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Common Physical Techniques in Purification 27

be activated by heating at 100-1 loo for a few hours. Other adsorbents (e.g. celluloses) adhere on glass plates without a setting agent. The materials to be purified are spotted in the solvent close to the lower end of the plate and allowed to dry. The spots will need to be placed at such a distance as to ensure that when the lower end of the plate is immersed in the solvent, the spots are a few mm above the eluting solvent. The plate is placed upright in a tank containing the eluting solvent. Elution is carried out in a closed tank as in paper chromatography to ensure equilibrium. It requires less than three hours for the solvent to reach the top of the plate. Good separations can be achieved with square plates if a second elution is performed at right angles to the first as in two dimensional paper chromatography. For rapid work plates of the size of microscopic slides or even smaller are used which can decrease the elution time to as little as fifteen minutes without loss of resolution. The advantage of plastic backed plates is that the size of the plate can be made as required by cutting the sheet with scissors. The thickness of the plates could be between 0.2mm to 2mm or more. The thicker plates are used for preparative work in which hundreds of milligrams of mixtures can be purified conveniently and quickly. The spots or areas are easily scraped off the plates and eluted with the required solvent. These can be revealed on the plates by UV light if they are UV absorbing or fluorescing substances, by spraying with a reagent that gives coloured products with the spot (e.g. iodine solution or vapour gives brown colours with amines), or with dilute sulphuric acid (organic compounds become coloured or black when the plates are heated at 100O) if the plates are of alumina or silica, but not cellulose. Some alumina and silica powders are available with fluorescent materials in them, in which case the whole plate fluoresces under UV light. Non-fluorescing spots are thus clearly visible, and fluorescent spots invariably fluoresce with a different colour. The colour of the spots can be different under W light at 254nm and at 365nm. Another useful way of showing up non-W absorbing spots is to spray the plate with a 1-276 solution of Rhodamine 6G in acetone. Under W light the dye fluoresces and reveals the non-fluorescing spots. If the material in the spot is soluble in ether, benzene or light petroleum, the spots can be extracted from the powder with these solvents which leave the water soluble dye behind. Thin and thick layer chromatography have been used successfully with ion-exchange celluloses as stationary phases and various aqueous buffers as mobile phases. Also, gels (e.g. Sephadex (3-50 to (3-200 superfine) have been adsorbed on glass plates and are good for fractionating substances of high molecular weights (1500 to 250,000). With this technique, which is called thin layer gel filfration (TLG), molecular weights of proteins can be determined when suitable markers of known molecular weights are run alongside. Commercially available precoated plates with a variety of adsorbents are generally very good for quantitative work because they are of a standard quality. More recently plates of a standardised silica gel 60 (as medium porosity silica gel with a mean porosity of 6mm) were released by Merck. These have a specific surface of 500 m2/g and a specific pore volume of 0.75 mug. They are so efficient that they have been called high performance thin layer chromatography (HPTLC) plates (Ropphahn and Halpap JC 112 81 1975). In another variant of thin layer chromatography the adsorbent is coated with an oil as in gas chromatography thus producing reverse- phase thin layer chromatography. A very efficient thin layer form of circular paper chromatography makes use of a circular glass disc coated with an adsorbent (silica, alumina or cellulose). The apparatus is called a Chromatotron (available from Harrison Research, USA). The disc is rotated by a motor, and the sample followed by the eluting solvent are allowed to drip onto a central position on the plate. As the plate rotates the solvent elutes the mixture, centrifugally, while separating the components in the form of circles radiating from the central point. When elution is complete the revolving circular plate is stopped and the circular bands are scraped off and extracted with a suitable solvent.

SOLVENT EXTRACTION AND DISTRIBUTION

Extraction of a substance from suspension or solution into another solvent can sometimes be used as a purification process. Thus, organic substances can often be separated from inorganic impurities by shaking an aqueous solution or suspension with suitable immiscible solvents such as benzene, carbon tetrachloride, chloroform, ethyl ether, isopropyl ether or petroleum ether. After several such extractions the combined organic phase is dried and the solvent is evaporated. Grease from the glass taps of conventional separating funnels is invariably soluble in the solvents used. Contamination with grease can be very troublesome particularly when the amounts of material to be extracted are very small. Instead, the glass taps should be lubricated with the extraction solvent; or better, the taps of the extraction funnels should be made of the more expensive material Teflon. Immiscible solvents suitable for extractions are given in Table 18. Addition of electrolytes (such as ammonium sulphate, calcium chloride or sodium chloride) to the aqueous phase helps to ensure that the organic

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2 8 Common Physical Techniques in Purification

layer separates cleanly and also decreases the extent of extraction into the latter. Emulsions can also be broken up by filtration (with suction) through Celite, or by adding a little octyl alcohol or some other paraffinic alcohol. The main factor in selecting a suitable immiscible solvent is to find one in which the material to be extracted is readily soluble, whereas the substance from which it is being extracted is not. The same considerations apply irrespective of whether it is the substance being purified, or one of its contaminants, that is taken into the new phase. (The second of these processes is described as washing.)

Common examples of washing with aqueous solutions include the following: Removal of acids from water-immiscible solvents by washing with aqueous alkali, sodium carbonate or sodium

Removal of phenols from similar solutions by washing with aqueous alkali. Removal of organic bases by washing with dilute hydrochloric or sulphuric acids. Removal of unsaturated hydrocarbons, of alcohols and of ethers from saturated hydrocarbons or alkyl halides by

bicarbonate.

washing with cold concentrated sulphuric acid.

This process can also be applied to purification of the substance if it is an acid, a phenol or a base, by extracting into the appropriate aqueous solution to form the salt which, after washing with pure solvent, is again converted to the free species and re-extracted. Paraffin hydrocarbons can be purified by extracting them with phenol (in which aromatic hydrocarbons are highly soluble) prior to fractional distillation. For extraction of solid materials with a solvent, a Soxhlet extractor is commonly used. This technique is applied, for example, in the alcohol extraction of dyes to free them from insoluble contaminants such as sodium chloride or sodium sulphate. Acids, bases and amphoteric substances can be purified by taking advantage of their ionisation constants. Thus an acid can be separated from other acidic impurities which have different pK, values and from basic and neutral impurities, by extracting a solution of the organic acid into an organic solvent (e.g. benzene or amyl alcohol) with a set of inorganic buffers of increasing pH (see Table 19). The acid will dissolve to form its salt in a set of buffers of pH greater than the pK, value. It can then be isolated by adding excess mineral acid to the buffer and extracting the free acid with an organic solvent. On a large scale, a countercurrent distribution machine (e.g. Craig type, see Quickfit and Quartz catalogue) can be used. In this way a very large number of liquid-liquid extractions can be carried out automatically. The closer the ionisation constants of the impurities are to those of the required material, the larger should the be the number of extractions to effect a good separation. A detailed discussion is available in review articles such as that in C.G.Casinovi's review, "A Comprehensive Bibliography of Separations of Organic Substances by Countercurrent Distribution" in Chromatographic Reviews 5 161 1963, and references on p. 47 under Solvents, Solvent Extraction and Distribution. This technique, however, appears to have been displaced almost completely by chromatographic methods.

MOLECULAR SIEVES

Molecular sieves are types of adsorbents composed of crystalline zeolites (sodium and calcium aluminosilicates). By heating them, water of hydration is removed, leaving holes of molecular dimensions in the crystal lattices. These holes are of uniform size and allow the passage into the crystals of small molecules, but not of large ones. This sieving action explains their use as very efficient drying agents for gases and liquids. The pore size of these sieves can be modified (within limits) by varying the cations built into the lattices. The three types of Linde (Union Carbide) molecular sieves currently available are:

Type 4A, a crystalline sodium aluminosilicate. Type 5A, a crystalline calcium aluminosilicate. Type 13X, a crystalline sodium aluminosilicate.

They are unsuitable for use with strong acids but are stable over the pH range 5- 1 1.

Type 4A sieves. The pore size is about 4 Angstroms, so that, besides water, the ethane molecules (but not butane) can be adsorbed. Other molecules removed from mixtures include carbon dioxide, hydrogen sulphide, sulphur dioxide, ammonia, methanol, ethanol, ethylene, acetylene, propylene, n-propyl alcohol, ethylene oxide and (below - 3 O O ) nitrogen, oxygen and methane. The material is supplied as beads, pellets or powder.

Type SA sieves. Because the pore size is about 5 Angstroms, these sieves adsorb larger molecules than type 4A. For example, as well as the substances listed above, propane, butane, hexane, butene, higher n-

Common Physical Techniques in Purification 2 9

olefines, n-butyl alcohol and higher n-alcohols, and cyclopropane can be adsorbed, but not branched-chain C6 hydrocarbons, cyclic hydrocarbons such as benzene and cyclohexane, or secondary and tertiary alcohols, carbon tetrachloride or boron trifluoride. This is the type generally used for drying gases.

Type 13X sieves. Their pore size of about 10 Angstroms enables many branched-chain and cyclic materials to be adsorbed, in addition to all the substances taken out by type 5A sieves.

Because of their selectivity, molecular sieves offer advantages over silica gel, alumina or activated charcoal, especially in their very high affinity for water, polar molecules and unsaturated organic compounds. Their relative efficiency is greatest when the impurity to be removed is present at low concentrations. Thus, at 25O and a relative humidity of 2%. type 5A molecular sieves adsorb 18% by weight of water, whereas for silica gel and alumina the figures are 3.5 and 2.5% respectively. Even at 100° and a relative humidity of 1.3% molecular sieves adsorb about 15% by weight of water. The much greater preference of molecular sieves for combining with water molecules explains why this material can be used for drying ethanol and why molecular sieves are probably the most universally useful and efficient drying agent. Percolation of ethanol with an initial water content of 0.5% through a 57-in long column of type 4A molecular sieves reduced the water content to IOppm. Similar results have been obtained with pyridine.

The main applications of molecular sieves to purification comprise: 1. Drying of gases and liquids containing traces of water. 2. Drying of gases at elevated temperatures. 3. Selective removal of impurities (including water) from gas streams.

(For example, carbon dioxide from air or ethylene; nitrogen oxides from nitrogen; methanol from ethyl ether. In general, carbon dioxide, carbon monoxide, ammonia, hydrogen sulphide, mercaptans, ethane, ethylene, acetylene, propane and propylene are readily removed at 2 5 O . In mixtures of gases, the more polar ones are preferentially adsorbed).

The following applications include the removal of straight-chain from branched-chain or cyclic molecules. For example, type 5A sieves will adsorb n-butyl alcohol but not its branched-chain isomers. Similarly, it separates n- tetradecane from benzene, or n-heptane from methylcyclohexane. A logical development is the use of molecular sieves as chromatographic columns for particular preparations. The following liquids have been dried with molecular sieves: acetone, acetonitrile, acrylonitrile, allyl chloride, amyl acetate, benzene, butadiene, n-butane, butene, butyl acetate, n-butylamine, n-butyl chloride, carbon tetrachloride, chloroethane, I-chloro-2-ethylhexane, cyclohexane, dichloromethane, dichloroethane, 1,2-dichloropropane, 1 , l - dimethoxyethane, dimethyl ether, 2-ethylhexanol, 2-ethylhexylamine, n-heptane, n-hexane, isoprene, isopropyl alcohol, isopropyl ether, methanol, methyl ethyl ketone, oxygen, n-pentane, phenol, propane, n-propyl alcohol, propylene, pyridine, styrene, tetrachloroethylene, toluene, trichloroethylene and xylene. In addition, the following gases have been dried: acetylene, air, argon, carbon dioxide, chlorine, ethylene, helium, hydrogen, hydrogen chloride, hydrogen sulphide, nitrogen, oxygen and sulphur hexafluoride. After use, molecular sieves can be regenerated by heating at between 150° and 300° for several hours, preferably in a stream of dry air, then cooling in a desiccator. However, care must be exercised in using molecular sieves for drying organic liquids. Appreciable amounts of impurities were formed when samples of acetone, 1,l ,I-trichloroethane and methyl-t-butyl ether were dried in the liquid phase by contact with molecular sieves 4A (Connett Lab.Practice 21 545 1972). Other, less reactive types of sieves may be more suitable but, in general, it seems desirable to make a preliminary test to establish that no unwanted reaction takes place. For the principles of synthesis and identification see R. Szostak Molecular Sieves, Chapman & Hall, London 1988, and for structure, synthesis and properties see RSzostak Handbook of Molecular Sieves, Chapman & Hall 1992.

SOME HAZARDS OF CHEMICAL MANIPULATION IN PURIFICATION AND RECOVERY FROM RESIDUES

Performing chemical manipulations calls for some practical knowledge if danger is to be avoided. However, with care, hazards can be kept to an acceptable minimum. A good general approach is t o consider every operation as potentially perilous and then to adjust one's attitude as the operation proceeds. A few of the commonest dangers are set out below. For a larger coverage of the following sections, and of the literature, the bibliography a t the end o f this chapter should be consulted. Several precautions on Safety in the chemical laboratory have been emphasised earlier in this monograph on page 3.

Perchlorates and perchloric acid. At 160° perchloric acid is an exceedingly strong oxidising acid and a strong dehydrating agent. Organic perchlorates, such as methyl and ethyl perchlorates, are unstable and are violently


explosive compounds. A number of heavy-metal perchlorates are extremely prone to explode. The use of anhydrous magnesium perchlorate anhydrone as a drying agent for organic vapours is not recommended. Desiccators which contain this drying agent should be adequately shielded at all times and kept in a cool place, i.e never on a window sill where sunlight can fall on it. No attempt should be made to purify perchlorates, except for ammonium, alkali metal and alkaline earth salts which, in water or aqueous alcoholic solutions are insensitive to heat or shock. Note that perchlorates react relatively slowly in aqueous organic solvents, but as the water is removed there is an increased possibility of an explosion. Perchlorates, often used in non-aqueous solvents, are explosive in the presence of even small amounts of organic compounds when heated. Hence stringent care should be taken when purifying perchlorates, and direct flame and infrared lamps should be avoided. Tetra-alkylammonium perchlorates should be dried below 50° under vacuum (and protection). Only very small amounts of such materials should be prepared, and stored, at any one time.

Peroxides. These are formed by aerial oxidation or by autoxidation of a wide range of organic compounds, including ethyl ether, allyl ethyl ether, allyl phenyl ether, benzyl ether, benzyl butyl ether, n-butyl ether, iso-butyl ether, t-butyl ether, dioxane, tetrahydrofuran, olefines, and aromatic and saturated aliphatic hydrocarbons. They accumulate during distillation and can detonate violently on evaporation or distillation when their concentration becomes high. If peroxides are likely to be present materials should be tested for peroxides before distillation (for tests see entry under "Ethers", in Chapter 2). Also, distillation should be discontinued when at least one quarter of the residue is left in the distilling flask.

Heavy-metal-containing explosives. Ammoniacal silver nitrate, on storage or treating, will eventually deposit the highly explosive silver nitride 'yufulminating silver". Silver nitrate and ethanol may give silver fulminate (see Chapter 4), and in contact with azides or hydrazine and hydrazides may form silver azide. Mercury can form such compounds. Similarly, ammonia or ammonium ions can react with gold salts to form "fulminating gold". Metal fulminates of cadmium, copper, mercury and thallium are powerfully explosive, and some are detonators [Luchs, Photog Sci Eng 10 334 19661. Heavy metal containing solutions, particularly when organic material is present should be treated with great respect and precautions towards possible explosion should be taken.

Strong acids. In addition to perchloric acid (see above), extra care should be taken when using strong mineral acids. Although the effects of concentrated sulphuric acid are well known these cannot be stressed strongly enough. Contact with tissues will leave irreparable damage. ALWAYS DILUTE THE CONCENTRATED ACID BY CAREFULLY ADDING THE ACID DOWN THE SIDE OF THE FLASK WHICH CONTAINS WATER, AND THE PROCESS SHOULD BE CARRIED OUT UNDER COOLING. THIS SOLUTION IS NOT SAFE TO HANDLE UNTIL THE ACID HAS BEEN THOROUGHLY MIXED WITH THE WATER. PROTECTIVE FACE AND BODY COVERAGE SHOULD BE USED AT ALL TIMES. Fuming sulphuric acid and chlorosulphonic acid are even more dangerous than concentrated sulphuric acid and adequate precautions should be taken. Chromic acid cleaning mixture (hot and cold, see p.4) contains strong sulphuric acid and should be treated in the same way; and in addition the mixture is potentially carcinogenic. Concentrated and fuming nitric acids are also dangerous because of their severe deleterious effects on tissues.

Reactive halides and anhydrides. Substances like acid chlorides, low molecular weight anhydrides and some inorganic halides (e.g. PCl3) can be HIGHLY TOXIC, LACHRYMATORY AFFECTING MUCOUS MEMBRANES AND LUNG TISSUES. UTMOST CARE SHOULD BE TAKEN WHEN WORKING WITH THESE MATERIALS. WORK SHOULD BE DONE IN A VERY EFFICIENT FUMECUPBOARD.

Solvents. The flammability of low-boiling organic liquids cannot be emphasised strongly enough. These invariably have very low flash points and can ignite spontaneously. Special precautions against explosive flammability should be taken when recovering such liquids. Care should be taken with small volumes (ca 250ml) as well as large volumes (> lL), and the location of all the fire extinguishers, and fire blankets, in the immediate vicinity of the apparatus should be checked. The fire extinguisher should be operational. The following flammable liquids (in alphabetical order) are common fire hazards in the laboratory: acetaldehyde, acetone, acrylonitrile, acetonitrile, benzene, carbon disulphide, cyclohexane, diethyl ether, ethyl acetate, hexane, low-boiling petroleum ethers, tetrahydrofuran and toluene. Toluene should always be used in place of benzene due to the potential carcinogenic effects of the liquid and vapour of the latter. The drying of flammable solvents with sodium or potassium metal and metal hydrides poses serious potential fire hazards and adequate precautions should be stressed.

Sal t s . In addition to the dangers of perchlorate salts, other salts such as nitrates and diazo salts can be hazardous and care should be taken when these are dried. Large quantities should never be prepared or stored for long periods.


TABLE 1A. PREDICTED EFFECT OF PRESSURE ON BOILING POINT* ~

Temperature in degrees Centigrade

760 mmHg 0 20 40 60 80 100 120 140 160 180

0.1 0.2

0 .4 0.6 0 . 8 1 .0 2.0 4 . 0 6.0 8 .0

10.0 14.0 16.0 20.0 30.0 40.0 50.0 60.0 80.0

100.0 150.0 200.0 300.0 400.0 500.0 600.0 700.0 750.0 770.0 800.0

-111 -105 -100 -96 -94 -92 -85 -78 -74 -70 -68 -64 -6 1 -59 -54 -50 -47 -44 -40 -37 -30 -25 -18 -13 -8 -5 -2 0 0 1

-99 -93 -87 -83 -8 1 -78 -7 1 -64 -59 -56 -5 3 -48 -45 -44 -38 -34 -30 -28 -23 -19 -12 -7 1 6

11 15 18 20 20 21

-87 -75 -81 -69 -74 -62 -70 -57 -67 -54 -65 -52 -58 -44 -49 -35 -44 -30 -41 -26 -38 -23 -33 -23 -29 -14 -28 -12 -22 -6 -17 -1 -14 3 -1 1 6 -6 11 -2 15 6 23

11 29 19 38 25 44 30 50 34 54 38 58 40 60 40 60 41 61

-63 -56 -49 -44 -4 1 -39 -30 -2 1 -15 -1 1

-8 -2 2 3

10 15 19 23 28 33 41 47 57 64 69 74 78 80 80 81

-5 1 -44 -36 -32 -28 -25 -16

-7 -1 4 7

13 17 19 26 32 36 40 45 50 59 66 75 83 88 93 98

100 100 101

-39 -32 -24 -19 -15 -12 -3 8

14 19 22 28 33 35 42 48 52 56 62 67 77 84 94

102 108 113 118 120 120 122

-27 -19 -1 1 -6 -2 1

11 22 29 34 37 44 48 50 58 64 69 73 79 85 95

102 113 121 127 133 137 140 140 142

-15 -7 2 7

11 15 25 36 43 48 53 59 64 66 74 81 86 86 97

102 112 120 131 140 147 152 157 160 160 162

-4 5

15 20 24 28 39 51 58 63 68 74 79 82 90 97

102 107 114 119 130 138 150 159 166 172 177 180 180 182

How to use the Table: Take as an example a liquid with a b.p. of 8OoC at 760mm Hg. The Table gives values of the b.ps of this liquid at pressures from 0.1 to 800mm Hg. Thus at 50mm Hg this liquid has a b.p. of 19OC, and at 2mm Hg its b.p. would be -3OOC.

*


TABLE 1B. PREDICTED EFFECT OF PRESSURE ON BOILING POINT'

Temperature in degrees Centigrade

760mmHg 200 220 240 260 280 300 320 340 360 380 400

0 .1 0.2 0.4 0.6 0 . 8 1 .o 2 .0 4.0 6 .0 8 . 0

10.0 14.0 18.0 20.0 30.0 40.0 50.0 60.0 80.0

100.0 150.0 200.0 300.0 400.0 500.0 600.0 700.0 750.0 770.0 800.0

8 17 27 33 38 41 53 65 72 78 83 90 95 97

106 113 119 123 131 137 148 156 169 178 185 192 197 200 200 202

20 30 40 40 51 54 66 79 87 93 98

105 111 113 123 130 135 140 148 154 166 174 187 197 205 21 1 217 220 220 222

32 42 53 59 64 68 80 93

102 108 113 120 126 129 139 146 152 157 165 171 184 193 206 216 224 23 1 237 239 24 1 242

44 54 65 72 77 81 94

108 116 123 128 136 142 144 155 162 168 174 182 189 20 1 21 1 225 235 244 25 1 257 259 26 1 262

56 67 78 85 90 94

108 122 131 137 143 151 157 160 171 179 185 190 199 206 219 229 243 254 263 270 277 279 28 1 282

68 79 91 98

103 108 121 136 146 152 158 166 173 176 187 195 202 207 216 223 237 247 262 273 282 290 296 299 301 302

80 91

103 111 116 121 135 151 160 167 173 182 188 191 203 21 1 218 224 233 24 1 255 265 28 1 292 302 310 316 319 32 1 322

92 103 116 124 130 134 149 156 175 182 188 197 204 207 219 228 235 24 1 250 258 273 283 299 311 321 329 336 339 34 1 342

104 116 129 137 143 147 163 179 189 197 203 212 219 223 235 244 25 1 257 267 275 290 302 318 330 340 349 356 359 361 262

115 128 141 150 156 161 176 193 204 212 218 228 235 238 25 1 260 268 274 284 293 308 320 337 350 360 368 376 279 38 1 382

127 140 154 163 169 174 190 208 219 227 233 243 25 1 254 267 277 284 29 1 30 1 3 10 326 338 355 369 379 388 396 399 40 1 403

How to use the Table: Taking as an example a liquid with a b.p. of 34OOC at 760mm Hg, the column headed * 34OOC gives values of the b.ps of this liquid at each value of pressures from 0.1 to 800mm Hg. Thus, at lOOmm Hg its b.p. is 258OC, and at 0.8mm Hg its b.p. will be 130OC.


TABLE 2. HEATING BATHS

u p to loo0 -20 to 200° Up to about 20O0 Up to about 250°

-40 to 250° Up to about 260°

Up to 340°

60 to 500° 150 to 500°

73 to 350°

250 to 800°

350 to 800°

Water baths Glycerol or di-n-butyl phthalate Medicinal paraffin Hard hydrogenated cotton-seed oil (m 40-60°) or a 1 : 1 mixture of cotton-seed oil and castor oil containing about 1% of hydroquinone. (to 400° under nitrogen); D.C. 550 silicone fluid A mixture of 85% orthophosphoric acid (4 parts) and metaphosphoric acid (1 part)

A mixture of 85% orthophosphoric acid (2parts) and metaphosphoric acid (1 part)

Fisher bath wax (highly unsaturated) A mixture of NaN02 (40%), NaN03 (7%) and KN03 (53%)

Wood’s Metal

Solder

Lead

* *

*

* In using metal baths, the container (usually a metal crucible) should be removed while the metal is still molten.

TABLE 3. WHATMAN FILTER PAPERS

Grade No.

Particle size retained in microns

* Filtration speed secllOOm1

1 2 3 4 5 6 113

11 8 5 1 2 2 .4 2.8 2 8

<300 125 9 4 0 5 5 155 2 0

Whatman routine ashless filters

Grade No. 40 4 1 4 2 43 4 4

Particle size retained in microns

* Filtration speed sec/lOOml

7.5 1 2 3 1 2 4

6 8 1 9 200 3 8 125

Whatman -___-_ Hardened------ ---Hardened ashless--

Grade No. 50 5 2 5 4 540 5 4 1 542

Particle size retained in microns 3 8 2 0 9 20 3

* Filtration speed sec/lOOml 250 5 5 10 5 5 1 2 250

continued


Whatman Glass Micro Filters (TABLE 3 continued)

Grade No GFIA GF/B GF/C GF/D GF/F

Particle size retained in microns 1.6 1 .o 1.1 2.2 0 . 8 Filtration * speed sed1 00ml 8.3 20.0 8.7 5.5 17.2 * Filtration speeds are rough estimates of initialflowrates and shouki be considered on a relative basis.

TABLE 4. MICRO FILTERS*

Nucleopore (polycarbonate) Filters

Mean Pore Size 8.0 2.0 1 .o 0.1 0.03 0.015 (microns) Av. pores/cm2 1 0 5 2x 106 2x107 3x10s 6x 1 Os 1 -6x 1 O9 Water flowrate ml/min/cm2 2000 2000 300 8 0.03 0.1-0.5

Millipore Filters #

Type Cellulose ester- -Teflon- -Microweb -

MF/SC MFNF LC Ls ws WH

Mean Pore Size (microns) Water flowrate ml/min/cm2

8 0.01 10 5 3 0.45

850 0.2 1 7 0 7 0 155 5 5

Gelman Membranes

Type -Cellulose ester- Copolymer- GA- 1 TCM-450 VM-IDM-800 AN-200 Tu ffryn-450

Mean Pore 5 0.45 5 0.8 0.2 0.45 Size(microns)

Water flow- 320 50 700 200 rate(mvmin/cm2 )

1 7 50

Sartorius Membrane Filters (SM)

Application Gravi- Biological Sterili- Particle For metric clarificatn. zation count in acids

bases

Type No. 11003 11004 1 1006 1101 1 12801 Mean Pore Size (microns) 1.2 0 .6 0.45 0.01 8

Water flowrate ml/min/cm2 300 150 6 5 0 . 6 1100

* Only a few representative filters are tabulated (available ranges are more extensive). # Reinforced nylon.

H20 &


TABLE 5. COMMON SOLVENTS USED IN RECRYSTALLISATION (and their boiling points)

Acetic acid (1 18O) *Acetone (56O) Acetylacetone (139O) *Benzene (800) Benzyl alcohol (93O/lOmrn)

Butyl acetate (126.5O) n-Butyl ether (142O) y-Butyrolactone (206O) Carbon tetrachloride (77O) Cellosolve (1 35O) Chlorobenzene (132O) Chloroform (61O)

n-Butanol(118O)

*Cyclohexane ( 8 lo) Diethyl cellosolve (121O) *Diethyl ether (34.5O) Dimethyl formamide (76O/39mm) *Dioxane ( 10 1 O)

*Ethanol (78O) *Ethyl acetate (78O) Ethyl benzoate (98O/19mm) Ethylene glycol (68O/4rnrn) Formamide (1 10°/l Omm) Glycerol (126O/1 l m m ) Isoamyl alcohol (1 3 lo) *Methanol (64.5O)

Methyl cyanide (82O) Methylene chloride ( 4 1 O)

*Methyl ethyl ketone (80O) Methyl isobutyl ketone (1 16O) Nitrobenzene (2100) Nitromethane ( 101 O)

*Petroleum ether (various) Pyridine (1 15.5O) Pyridine trihydrate (93O) *Tetrahydrofuran (64-66O) Toluene ( 1 100) Trimethylene glycol (59O/1 l m m ) Water ( 1 W )

Highly flammable, should be heated or evaporated on steam or electrically heated water * baths only (preferably in a nitrogen atmosphere).

TABLE 6. PAIRS OF MISCIBLE SOLVENTS

Acetic acid: with chloroform, ethanol, ethyl acetate, methyl cyanide, petroleum ether, or water. Acetone: with benzene, butyl acetate, butyl alcohol, carbon tetrachloride, chloroform, cyclohexane, ethanol,

Ammonia: with ethanol, methanol, pyridine. Aniline: with acetone, benzene, carbon tetrachloride, ethyl ether, n-heptane, methanol, methyl cyanide or

nitrobenzene. Benzene: with acetone, butyl alcohol, carbon tetrachloride, chloroform, cyclohexane, ethanol, methyl

cyanide, petroleum ether or pyridine. Butyl alcohol: with acetone or ethyl acetate. Carbon disulphide: with petroleum ether. Carbon tetrachloride: with cyclohexane. Chloroform: with acetic acid, acetone, benzene, ethanol, ethyl acetate, hexane, methanol or pyridine. Cyclohexane: with acetone, benzene, carbon tetrachloride, ethanol or ethyl ether. Dimethyl formamide: with benzene, ethanol or ether. Dimethyl sulphoxide: with acetone, benzene, chloroform, ethanol, ethyl ether or water. Dioxane: with benzene, carbon tetrachloride, chloroform, ethanol, ethyl ether, pet. ether, pyridine or water. Ethanol: with acetic acid, acetone, benzene, chloroform, cyclohexane, dioxane, ethyl ether, pentane,

Ethyl acetate: with acetic acid, acetone, butyl alcohol, chloroform, or methanol. Ethyl ether: with acetone, cyclohexane, ethanol, methanol, methylal, methyl cyanide, pentane or pet.ether. Glycerol: with ethanol, methanol or water. Hexane: with benzene, chloroform or ethanol. Methanol: with chloroform, ethyl ether, glycerol or water. Methylal: with ethyl ether. Methyl ethyl ketone: with acetic acid, benzene, ethanol or methanol. Nitrobenzene: with aniline, methanol or methyl cyanide. Pentane: with ethanol or ethyl ether. Petroleum ether: with acetic acid, acetone, benzene, carbon disulphide or ethyl ether. Phenol: with carbon tetrachloride, ethanol, ethyl ether or xylene. Pyridine: with acetone, ammonia, benzene, chloroform, dioxane, petroleum ether, toluene or water. Toluene: with ethanol, ethyl ether or pyridine. Water: with acetic acid, acetone, ethanol, methanol, or pyridine. Xylene: with ethanol or phenol.

ethyl acetate, methyl acetate, methyl cyanide, petroleum ether or water.

toluene, water or xylene.

36 Common Physical Techniques in Purification

TABLE 7. MATERIALS FOR COOLING BATHS Temperature Composition

0' Crushed ice -77' Solid C02 with chloroform or acetone -5' to -200 Ice-salt mixtures -78' Solid C02 (powdered) -33' Liquid ammonia -lW Solid C02 with ethyl ether -400 to -50' Ice (3.5-4 parts) - CaC12 6H2O (5 parts) -192' -72' Solid C02 with ethanol . -196' liquid nitrogen (see footnote*)

liquid air

Alternatively, the following liquids can be used, partially frozen, as cryostats, by adding solid COz from time to time to the material in a Dewar-type container and stimng to make a slush:

13' 12' 6' 5' 2'

-8.6' -9' - 10.5' -11.9' -12' -15' -16.3' -18' -22' -22.4' -22.8' -24.5' -25' -29'

-83.6' -86' -89' -900

-92' -93' -94' -94.6' -95.1' -97'

For other

-91'

pXylene Dioxane Cyclohexane Benzene Formamide Methyl salicylate Hexane-2Jdione Ethylene glycol rerr-Amyl alcohol Cycloheptane or methyl benzoate Benzyl alcohol n-Octanol 1 ,2-Dichlorobenzene Tetrachloroethylene Butyl benzoate Carbon tetrachloride Diethyl sulphate 1,3-Dichlorobenzene @Xylene or pentachloroethane

Ethyl acetate Methyl ethyl ketone

Nitroethane Heptane n-Propyl acetate 2-Nitropropane or cyclopentane Ethyl benzene or hexane Acetone Toluene Cumene

n-Butanol

-30' -32' -32.6' -38' -41' -42' -44' -45' -47' -500 -52' -55' -56' -600 -73' -74' -77' -79' -83'

-98'

-1040 -107' -108' -116' -1 17' - 126' -131' - 160'

-99'

Bromobenzene m-Toluidine Dipropyl ketone Thiophen Methyl cyanide Pyridine or diethyl ketone Cyclohexyl chloride Chlorobenzene m-Xylene Ethyl malonate or n-butylamine Benzyl acetate or diethylcarbitol Diacetone n-Octane Isopropyl ether Trichloroethylene or isopropyl acetate o-Cymene or p-cymene Butyl acetate Isoamyl acetate Propylamine

Methanol or methyl acetate Isobutyl acetate Cyclohexene Isooctane 1 -Nitropropane Ethanol or ethyl ether Isoamyl alcohol Methylcyclohexane n-Pentane Isopentane

organic materials used in low temperature slush-baths with liquid nitrogen see R.E.Rondeau [J.Chem.Eng.Dufu 11 124 19661. NOTE that the liquid nitrogen should be oxygen-free. Liquid nitrogen that has been in contact with air will contain oxygen (see Table 8 for boiling points) and should not be used.

Use high quality pure nitrogen, do not use liquid air or liquid nitrogen that has been in contact with air for a long period (due to the dissolution of oxygen in it) which could EXPLODE in contact with organic matter. If the quality of the liquid nitrogen is not known, or is uncertain then it should NOT be used.

*


TABLE 8. BOILING POINTS OF SOME USEFUL GASES AT ONE ATMOSPHERE PRESSURE

Argon -185.6' Krypton -152.3' Carbon dioxide - 7 8 3 ' Methane - 164.0' (sublimes) Carbon monoxide Ethane Helium Hydrogen

Neon -191.3' Nitrogen

-268.6' Nitric oxide -252.6' Oxygen

-88.6' Nitrous oxide

-246.0' -209.9'

-88.5' - 195.8' -182.96'

TABLE 9. LIQUIDS FOR DRYING PISTOLS Boiling points (760mm) Boiling points (760mm)

Ethyl chloride Methylene dichloride Acetone Chloroform Methanol Carbon tetrachloride Ethanol Benzene Trichloroethylene

12.2' 39.8' 56.1' 62.0' 64.5' 76.5' 78.3' 79.8' 86.0'

Water Toluene Tetrachloroethylene Chlorobenzene m-Xylene Isoamyl acetate Tetrachloroethane B romobenzene p-Cymene Tetralin

100.0' 110.5' 121.2' 132.0' 139.3' 142.5' 146.3' 155.0' 1 76.0' 207.0'

TABLE 10. VAPOUR PRESSURES (mm Hg) OF SATURATED AQUEOUS SOLUTIONS IN EQUILIBRIUM WITH

S a l t Temperature % Humidity SOLID SALTS

l o o 1 5 O 20' 2 5 O 30° at 20°

LiCI.H20 2.6 15 CaBr2.6H20 2.1 2.7 3.3 4.0 4.8 19 KOAc 3.5 20 CaC12.6H20 3.5 4.5 5.6 6.9 8.3 20 ca3 6.1 32 Zn(N03)2.6H20 7.4 42 K2C03.2H20 7 .7 10.7 44 KCNS 8 .2 47 Na2Cr207.2H20 9.1 52 Ca(N03)2.4H20 6.0 7.7 9.6 11.9 14.2 55 Mg(N03)2.6H20 9.8 56 NaBr.2H20 5.8 7.8 10.3 13.5 17.5 58 NaNO2 11.6 66 NaC103 13.1 75 NaCl 6.9 9.6 13.2 17.8 21.4 75 NaOAc 13.3 76 NH&1 13.8 79

KBr 14.7 8 4 KHS04 15.1 8 6 KCI 15.1 20.2 27.0 8 6 K2Cfl4 15.4 88 ZnS04.7H20 15.8 90

(NH4)2S04 14.2 8 1

NH4.H2P04 16.3 93 KNo3 16.7 22.3 29.8 95 Pb(N03)2 17.2 98 Water) 9.21 12.79 17.53 23.76 31.82 100


TABLE 11. DRYING AGENTS FOR CLASSES OF COMPOUNDS Class Dried with

Acetals Acids (organic) Acyl halides Alcohols

Aldehydes Alkyl halides

Amines

Aryl halides

Esters Ethers

Heterocyclic bases Hydrocarbons

Ketones

Mercaptans Nitro compounds and Nitriles Sulphides

Potassium carbonate Calcium sulphate, magnesium sulphate, sodium sulphate. Magnesium sulphate, sodium sulphate. Calcium oxide, calcium sulphate, magnesium sulphate, potassium carbonate, followed by magnesium and iodine. Calcium sulphate, magnesium sulphate, sodium sulphate. Calcium chloride, calcium sulphate, magnesium sulphate, phosphorus pentoxide, sodium sulphate. Barium oxide, calcium oxide, potassium hydroxide, sodium carbonate, sodium hydroxide. Calcium chloride, calcium sulphate, magnesium sulphate, phosphorus pentoxide, sodium sulphate. Magnesium sulphate, potassium carbonate, sodium sulphate. Calcium chloride, calcium sulphate, magnesium sulphate, sodium, lithium aluminium hydride. Magnesium sulphate, potassium carbonate, sodium hydroxide. Calcium chloride, calcium sulphate, magnesium sulphate, phosphorus pentoxide, sodium (not for olefines). Calcium sulphate, magnesium sulphate, potassium carbonate, sodium sulphate. Magnesium sulphate, sodium sulphate.

Calcium chloride, magnesium sulphate, sodium sulphate. Calcium chloride, calcium sulphate.

~~ ~

TABLE 12. GRADED ADSORBENTS AND SOLVENTS

Adsorbents (decreasing effectiveness)

Solvents (inreasing eluting ability)

Fuller's earth (hydrated aluminosilicate) Magnesium oxide Charcoal Alumina Magnesium trisilicate Silica gel Calcium hydroxide Magnesium carbonate Calcium phosphate Calcium carbonate Sodium carbonate Talc Inulin Sucrose = starch

Petroleum ether, b 4 0 - 6 0 O .

Petroleum ether, b 60-80°. Carbon tetrachloride. Cyclohexane . Benzene. Ethyl ether. Chloroform. Ethyl acetate. Acetone. Ethanol. Methanol. Pyridine. Acetic acid.


TABLE 13. REPRESENTATIVE ION-EXCHANGE RESINS

Sulphonated polystyrene Strong-acid cation exchanger

Amberlite IR-120 Dowex 50W-x8 Duolite 225 Permutit RS Permutite C50D

AG 5OW-x8

Carboxylic acid-type Weak acid cation exchangers Amberlite IRC-50 Bio-Rex 70 Chelex 100 Duolite 436 Permutit C Permutits H and H-70

Aliphatic amine-type weak base anion exchangers Amberlites IR-45 and IRA-67 Dowex 3-x4A Permutit E Permutit A 240A

Strong Base, anion exchangers AG 2x8 Amberlite IRA400 Dowex 2-x8 Duolite 113 Permutit ESB Permutite 330D

Distributor

(Bio-Rad, USA) (Rohm and Haas, USA) (Dow Chemical Co., USA) (Dia-Prosim Ltd) (Permutit AG, Germany) (Phillips and Pain-Vermorel, France)

(Rohm and Haas, USA) (Bio-Rad, USA) (Bio-Rad, USA) (Dia-Prosim Ltd) (Permutit AG, Germany) (Permutit Co, USA)

(Rohm and Haas, USA) (Dow Chemical Co, USA) (Permutit AG, Germany) (Phillips and Pain-Vermorel, France)

(Bio-Rad, USA) (Rohm and Haas, USA) (Dow Chemical Co, USA) (Dia-Prosim Ltd) (Permutit AG, Germany) (Phillips and Pain-Vermorel, France)

TABLE 14. MODIFIED FIBROUS CELLULOSES FOR ION-EXCHANGE

Cation exchange Anion exchange

CM cellulose (carboxymethyl) CM 22, 23 cellulose P cellulose (phosphate) SE cellulose (sulphoethyl) SM cellulose (sulphomethyl)

DEAE cellulose (diethylaminoethyl) DE 22, 23 cellulose PAB cellulose @-aminobenzyl) TEAE cellulose (triethylaminoethyl) ECTEOLA cellulose

SE and SM are much stronger acids than CM, whereas P has two ionisable groups (pK 2-3, 6-7). one of which is stronger, the other weaker, than for CM (3.5 - 4.5).

For basic strengths, the sequence is: TEAE >> DEAE (PK 8 - 9.5) > ECTEOLA (PK 5.5 - 7) > PAB. Their exchange capacities lie in the range 0.3 to 1.0 mg equiv./g.


TABLE 15. BEAD FORM ION-EXCHANGE PACKAGINGS'

Cation exchange Capacity Anion exchange Capacity (meqk) (meq/g)

CM-Sephadex C-25, 4.5M.5 DEAE-Sephadex A-25, 3.5k0.5 C-50.2(weak acid) A-50.7 (weak base)

SP-Sephadex C-25, 2.339.3 QAE-Sephadex A-25, 3.W0.4 C-50.3(strong acid) A-50.8 (strong base)

CM-Sepharose DEAE-Sepharose CL-6B.4 0.12M.02 CL-6B.4 0.13M.02

Fractogel EMD,CO;(pK -4.5) ,

so, (PK -< 11.5

DEAE-Sepha~el.~ 1.4kO.l

Fractogel EMD, DMAE (pK -9),

DEAE (PK -10.8), "MAE (PK >13).5

CM-32 Cellulose. DE-32 Cellulose.

CM-52 Cellulose.6 DE-52 Cellulose

May be sterilised by autoclaving at pH 7 and below 120O. Carboxymethyl. Sulphopropyl. Crosslinked agarose gel, no precycling required, pH range 3-10. Hydrophilic methacrylate polymer with very little volume change on change of pH (equivalent to Toyopearl), available in superfine 650S, and medium 650M particle sizes. Microgranular, pre-swollen, does not require precycling. Diethylaminoethyl. Diethyl(2- hydroxypropy1)aminoethyl. Bead form cellulose, pH range 2- 12, no precycling. Sephadex and Sepharose from Pharmacia, Fractogel from Merck, Cellulose from Whatman

TABLE 16. COLUMNS FOR HPLC'>2

Column Mobile Phase3 Application

DUPONT

ODs" permaphase" Most solvents, not (octadecyl strong acids and silane). bases, for gradient

elution.

HCP (hydrocarbon Aqueous alcohols up polymer). to 50% isopropanol.

CWT (carbowax 4000).

Hydrocarbons only.

TMG (trimethylene Hydrocarbons, CHC13, methylene glycol) dioxane and tetra-

hydrofuran. Not alcohols, Phase must be saturated with trimethylene glycol.

Aromatic compds, sterols, drugs, natural products.

Aromatic compds. quinones.

Steroids and polar organic compounds.

Hydroxy and amino compds, pesticides, polymer inter- mediates.

continued


TABLE 16 (cont.). COLUMNS FOR HPLC'*2

Column Mobile Phase3 Application

BOP (2.2'-oxydi- propionitrile).

WAX (weak anion exchange).

SAX (strong anion exchange).

SCX (strong cation exchange).

MERCK

Silica Gel 60- Kieselgel 60.

LiChromosorb SI60 SI 100 and Altex T.

Perisorb A.

Perisorb PA6.

Perisorb KAT

BAKER

Bakerbond Chiral DNBPG (ionic or c o v a ~ e n t ) . ~

DNBLeu (COV-

a ~ e n t ) . ~

Hydrocarbons, butyl ether, up to 15% of THF. Phase must be satd with 2,T-oxydi- propioni trile.

Water only, retention and resolution are modified by pH and ionic strength

Alkaloids, pesticides, polymer additives, steroids

Ionic compounds.

Water only, as above. As above.

Water only, as above. As above.

EtOH, CHC13, CH2CI2,

acetic acid.2 n-C7H 16, EtOAc,

Hydrocarbons, ether aliphatic acids, MezSO, CHC13, CH2Cl2 t-BuOH.

Hexane, acetic acid, isooctane, EtOAc.

MeOH, H20, AcOH.

Aq. Buffers to pH 11

t-BuOH, 2-PIOH. Butyl methyl ether, hexane, CHC13, and phases below.

Chiral phases: S-Asp- artyl-S-phenylalanine methyl ester, N,N-Di- propyl-S-alanine cupric acetate.

Vitamins, alkaloids esters, steroids, drugs, aromatic, compds.

As above, phthal- imido-acids, anti- oxidants.

Acids, esters, aromatic amines and hydrocarbons.

As above.

Heterocycles, nucleosides, acids and bases.

Chiral mixts of alcohols, acids, amines, variety of enantiomeric compds

Phosphonates, aryl- sulphoxides, nitrogen heterocycles, di-0-naphthols.

Only a few representative columns are tabulated, there is a very much larger selection avaliable commerially. Altex, T.J.Baker, Bio-Rad, Merck, Pharmacia, Waters Assoc. also have a wide range of columns. Not to be used above 50°, halide acids and salts are corrosive and must be avoided.

4R-N- 3,5-dinitrobenzoylphenylglycine. 5R- N-3,5-dinitrobenzoylleucine.


TABLE 17. LIQUIDS FOR STATIONARY PHASES IN GAS CHROMATOGRAPHY

Material Temp. Retards

Dimethy lsulpholane Di-n-butyl phthalate Squalane Silicone oil or grease Diglycerol

Dinonyl phthalate Polydiethylene glycol succinate Polyethylene glycol

Apiezon grease Tricresyl phosphate

0-40' 0-40' 0- 150' 0-250' 20- 120'

20- 130' 50-200'

50-200'

50-200' 50-250'

Olefines and aromatic hydrocarbons General purposes Volatile hydrocarbons and polar molecules General purposes Water, alcohols, amines, esters, and aromatic hydrocarbons General purposes Aromatic hydrocarbons, alcohols, ketones, esters. Water, alcohols, amines, esters and aromatic hydrocarbons Volatile hydrocarbons and polar molecules General purposes

TABLE 18. SOME COMMON IMMISCIBLE OR SLIGHTLY MISCIBLE PAIRS OF SOLVENTS

Carbon tetrachloride with ethanolamine, ethylene glycol, formamide or water. Dimethyl formamide with cyclohexane or petroleum ether. Dimethyl sulphoxide with cyclohexane or petroleum ether. Ethyl ether with ethanolamine, ethylene glycol or water. Methanol with carbon disulphide, cyclohexane or petroleum ether. Petroleum ether with aniline, benzyl alcohol, dimethyl formamide, dimethyl sulphoxide, formamide,

furfuryl alcohol, phenol or water. Water with aniline, benzene, benzyl alcohol, carbon disulphide, carbon tetrachloride, chloroform,

cyclohexane, cyclohexanol, cyclohexanone, ether (particularly if acidified), ethyl acetate, isoamyl alcohol, methyl ethyl ketone, nitromethane, tributyl phosphate or toluene.


TABLE 19. AQUEOUS BUFFERS

Approx. pH Composition

0 2N sulphuric acid or N hydrochloric acid

1 0.1N hydrochloric acid or 0.18N sulphuric acid

2 Either 0.01N hydrochloric acid or 0.013N sulphuric acid Or 50 ml of 0.1M glycine (also 0.1M NaCI) + 50 ml of 0.1N hydrochloric acid

3 Either 20 ml of the 0.2M Na2HP04 + 80 ml of 0.1M citric acid Or 50 ml of 0.1M glycine + 22.8 ml of 0.1N hydrochloric acid in 100 ml

4 Either 38.5 ml of 0.2M Na2HP04 + 61.5 ml of 0.1M citric acid Or 18 ml of 0.2M NaOAc + 82 ml of 0.2M acetic acid

S Either 70 ml of 0.2M NaOAc + 30 ml of 0.2M acetic acid Or 51.5 ml of 0.2M Na2HP04 + 48.5 ml of 0.1M citric acid

6 63 ml of 0.2M NazHP04 + 37 ml of 0.1 M citric acid

7 82 ml of M Na2HP04 + 18 ml of 0.1M citric acid

8 Either 50 ml of 0.1M Tris buffer + 29 ml of 0.1N hydrochloric acid, in 100 ml Or 30 ml of 0.05M borax + 70 ml of 0.2M boric acid

9 80 ml of 0.05M borax + 20 ml of 0.2M boric acid

1 0 Either 25 ml of 0.05M borax + 43 ml of 0.1N NaOH, in 100 ml Or 50 ml of 0.1M glycine + 32 ml of 0.1N NaOH, in 100 ml

1 1 50 ml of 0.15M Na2HP04 + 15 ml of 0.1N NaOH

1 2 50 ml of 0.15M Na2HP04 + 75 ml of 0.1N NaOH

1 3 0.1 N NaOH or KOH

1 4 N NaOH or KOH

These buffers are suitable for use in obtaining ultraviolet spectra. Alternatively, for a set of accurate buffers of low, but constant, ionic strength (I = 0.01) covering a pH range 2.2 to 11.6 at 200, see Perrin Australian J Chem 16 572 1963.


BIBLIOGRAPHY

The following books and reviews provide fuller details of the topics indicated.

Affinity Chromatography

I.A.Chaiken, Analytical Affinity Chromatography, CRC Press Inc, Florida, 1987. P.D.G.Dean, W.S.Johnson and F.A.Middle, Affinity Chromatography (a practical approach), IRL Press,

E.V.Gorman and M. Wilchek, Recent Developments in Affinity Chromatography Effects, Trends in

W.B.Jakoby and M.Wilchek, Affinity Chromatography in Methods in Enzymology, 34, 1975. T.Kline, Handbook of Affinity Chromatography, M Dekker Inc., NY, 1993. C.R.Lowe and P.D.G.Dean, Affinity Chromatography, Wiley & Sons, NY, 1974. J.Turkova, Affinity Chromatography, Elsevier, Amsterdam, 1978,

Oxford, 1985.

Biotechnology, 5 220 1987.

Chiral Chromatography

S.Allenmark, Chromatographic Enantioseparations (Methods and Applications), 2nd Edn, Eliss Horwood

W.A.Konig, The Practice of Enantiomeric Separation by Capillary Gas Chromatography, Huethig,

GSubramanian (ed.), A Practical Approach to Chiral Separations by Liquid Chromatography, VCH

Publ. NY, 1991.

1987.

Publ., Weinheim, 1994.

Chromatography

P.R.Brown and A.Grushka, Advances in Chromatography, M. Dekker, NY, vol34 1994, vol35 1995. W.D.Conway and R.J.Petroski, Modem Countercurrent Chromatography, American Chemical Society,

J.C.Giddings, E.Grushka and P.R.Brown (eds), Advances in Chromatography, (M.Dekker), Vols 1-36,

E.Lederer and M.Lederer, Chromatography, A Review of Principles and Applications, 2nd edn, Elsevier,

R.M.Smith, Retention and Selectivity Studies in Liquid Chromatography: Prediction, Standardisation

W.L.Hinze and D.W.Armstrong, eds, Ordered Media in Chemical Separations, ACS Symposia Series

C.F.Poole and K.S.Poole, Chromatography Today, Elsevier, Amsterdam, 199 1. K.K.Unger (ed.), Packings and Stationary Phases in Chromatographic Techniques, M.Dekker, Inc., NY,

1995.

1955- 1995.

Amsterdam, 1957.

and Phase Comparisons, Elsevier, Amsterdam, 1994.

342, ACS, Washington DC, 1987.

1990.

Crystallisation

C.W.Carter (ed.), Protein and Nucleic Acids Crystallisation Methods - A Companion to Methods in

A.Ducruix and R.Giege, Crystallisation of Nucleic Acids and Proteins, IRL Press, Oxford, 1992. A.Mersmann (ed.), Crystallisation Technology Handbook, M.Dekker Inc. NY, 1994. R.S.Tipson, in A.Weissberger (ed), Techniques of Organic Chemistry, vol 111, pt I, 2nd edn, Interscience,

H.Miche1, Crystallisation of Membrane Proteins, CRC Press, Boca Raton, 1991. J.Nyvit and J.Ulrich, Admixtures in Crystallisation, VCH Publ. Inc., Weinheim, 1995. Proceedings of the 5th Interrnational Conference on Crystallography of Biological Macromolecules (San

Enzymology, Academic Press, NY, 1 12 1990.

NY, 1956.

Diego, Acta Crystallographica Section D, 50 Part 4 337-666 1994.


Distillation

T.P.Carney, Laboratory Fractional Distillation, Macmillan, NY, 1949. E.Krel1, Handbook of Laboratory Distillation, Elsevier, Amsterdam, 1963. K.Sattler and H.J.Feiner, T h e m 1 Separation Processes, VCH Publ. Inc., Weinheim, 1994. A.Weissberger (ed), Techniques of Organic Chemistry, vol IV, Distillation, Interscience, New York,

C.L.Yaws, Handbook of Vapour Pressure, (4 vols), Gulf Publ. Co., 1995. 1951.

Drying

G.Broughton, in A.Weissberger's (ed) Techniques of Organic Chemistry, vol 111, pt I, 2nd edn, Interscience, New J.A.Riddick and W.B.Bunger, Organic Solvents: Physical Properties and Methods of Purification, Techniques of Chemistry, Vol 11, Wiley-Interscience, NY, 1970.

J.F.Coetzee (ed), Purification of Solvents, Pergamon Press, Oxford, 1982.

Gas Chromatography

D.Ambrose, Gas Chromatography, 2nd edn, Butterworths, London, 197 1. P.J.Baugh (ed.), Gas Chromatography (a practical approach), Oxford University Press, Oxford, 1993. G.Guichon and C.L.Guillemin, Quantitative Gas Chromatography for Laboratory and On-Line Process

W.Hemes, Capillary Gas Chromatography-Fourier Transform Infra Red Spectroscopy-Applications,

H.Jaeger, Capillary Gas Chromatography-Mass Spectrometry in Medicine and Pharmacology, Huethig,

R.A.Jones, An Introduction to Gas-Liquid Chromatography, Academic Press, London, 1970. R.Kaiser, Gas Chromatography, vo1.3, Butterworths, London, 1963 (practical details of liquid phases,

A.B .Littlewood, Gas Chromatography: Principles, Techniques and Applications, 2nd edn, Academic

R.W.Zumwalt, K.C.Kuo and C.W.Gehrke, Amino Acid Analysis by Gas Chromatography, CRC Press

Control, Elsevier, Amsterdam, 1988.

Huethig, 1987.

1987.

adsorbents, etc., with references).

Press, NY, 1970.

Inc, Florida, 1987.

Gel Filtration

H.Detemann, Gel Filtration, Springer-Verlag, Berlin, 1969. P.L.Dubin, Aqueous Size-Exclusion Chromatography, Elsevier, Amsterdam, 1988. L.Fischer, Gel Filtration, 2nd edn, ElsevierNorth-Holland, Amsterdam, 1980. P.Flodin, Dextran Gels and Their Applications in Gel Filtration, Pharmacia, Uppsala, Sweden, 1962. C-S.Wu, Handbook of Size Exclusion Chromatography, M.Dekker Inc., NY, 1995.

High Performance Liquid Chromatography

T.J.Baker, Chemists, HPLC Solvents Reference Manual, T.J.Baker Chemical Co., 1985. B.A.Bidlingmeyer, Preparative Liquid Chromatography, Elsevier, Amsterdam, 1987. H.Engelhardt, High Performance Liquid Chromatography, (translated from the German by G.Gutnikov),

R.W.Frei and K.Zech, Selective Sample Handling and Detection in High Performance Liquid

J.J.Kirkland, Columns for HPLC, Anal.Chem., 43(12) 36A 1971. A.M.Krstulovic and P.R.Brown, Reversed Phase HPLC. Theory, Practical and Biomedical Applications,

C.K.Lim (ed.), HPLC of Small Molecules, IRL Press, Oxford, 1986.

Springer-Verlag, Berlin, 1979.

Chromatograph, Elsevier, Amsterdam, Part A, 1988 and Part B 1989.

Wiley & Sons, NY, 1982.


W.J.Lough and I.W.Wainer, High Pegormance Liquid Chromatography, Chapman & Hall, London,

E.Molner (ed), Practical Aspects of Modem HPLC, W.deGmyter, Berlin, 1983. R.W.A.Oliver (ed.), HPLC of Macromolecules, IRL Press, Oxford, 1988. G.Szepes, Reverse Phase HPLC, VCH Publ. Inc., NY, 1992. F.J.Yang, Microbore Column Chromatography, M.Dekker, Inc., NY, 1989.

1995.

Ionic Equilibria

G.Kortiim, W.Vogel and K.Andrussow, Dissociation Constants of Organic Acids in Aqueous Solution,

D.D.Pemn, Dissociation Constants of Organic Bases in Aqueous Solution, Butterworths, London, 1965;

D.D.Pemn, Dissociation Constants of Inorganic Acids and Bases in Aqueous Solution, Butterworths,

D.D.Pemn and B.Dempsey, Buffers forpH and Metal Ion Control, Chapman and Hall, London, 1974. E.P.Serjeant and B.Dempsey, Ionization Constants of Organic Acids in Aqueous Solution, Pergamon

Butterworths, London, 1961.

and Supplement 1972.

London, 1969.

Press, Oxford, 1979.

Ion Exchange

C.Calmon and T.R.E.Kressman (eds), ton Exchangers in Organic and Biochemistry, Interscience, NY,

Dowex: ton Exchange, Dow Chemical Co., Midland, Michigan, 1959. D.T.Gjerde and J.S.Fritz, ton Chromatography, 2nd edn, Dr A.Hiithig Verlag, Heidelberg, 1987. C.G.Horvath, ton Exchangers, Vol. 3, Dekker, NY, 1972. ton Exchange Resins, British Drug Houses, 5th edn, Poole, England, 1977. J.Khym, Analytical ton Exchange Procedures in Chemistry and Biology, Prentice Hall, NJ, 1974. J.Weiss, Zon Chromatography, VCH Publ. Inc., Weinheim, 1995. E.A.Peterson in Laboratory Techniques in Biochemistry and Molecular Biology, Vol 2, Pt 11, T.S.Work

H.F.Walton (ed), ton-exchange Chromatography, Dowden, Hutchinson and Ross Inc., Stroudsburg, Pa.,

1957.

and E.Work (eds), North Holland, Amsterdam, 1970.

distributed by Halstead Press, 1976.

Laboratory Technique and Theoretical Discussion

K.L.Cheng, K.Ueno and T.Imamura, CRC Handbook of Organic Analytical Reagents, CRC Press Inc.,

P.S.Diamond and R.F.Denman, Laboratory Techniques in Chemistry and Biochemistry, 2nd edn,

Fieser and Fieser's Reagents for Organic Chemistry, Vols 1 to 15, Wiley-Interscience, NY, 1967 to

B.S.Furniss, A.J.Hannaford, V.Rogers, P.W.G.Smith and A.R.Tatchel1, Vogel's Textbook of Practical

C.J.O.R.Mon-is and P.Moms, Separation Methods in Biochemistry, 2nd edn, Interscience, NY, 1976. R.K.Scopes, Protein Purification. Principles and Practice, 3rd edn, Springer-Verlag, NY, 1994. G. Svehla, Vogel's Textbook of Macro and Semimicro Qualitative Organic Analysis, 5th edn,

Florida, 1982.

Butterworths, 1973.

1990.

Organic Chemistry, 4th edn, Longmans, London, 198 1.

Longmans, London 1979.

Molecular Sieves

P.Andrews, Molecular Sieve Chromatography, Brit.Med.Bull., 22 109 1966. D.W.Breck, Zeolite Molecular Sieves. Structure, Chemistry and Use, Wiley & Sons, NY, 1974. R.Szostak, Handbook of Molecular Sieves, Chapman & Hall, London, 1992.


Union Carbide Molecular Sieves for Selective Adsorption, 2nd edn, British Drug Houses, Poole, England, 1961.

Safety in the Chemical Laboratory

L.Bretherick, Handbook of Reactive Chemical Hazards, 3rd edn, Butterworths, London, 1985. College Safety Committee, Code of Practice against Radiation Hazards, 6th edn, Imperial College,

R.Cote and P.Wells, Controlling Chemical Hazards, Chapman & Hall, London, 1991. M.J.Lefevre, First Aid Manual for Chemical Accidents, Dowden, Hutchinson and Ross, PA, 1980. R.E.Lenga (ed.), The Sigma-Aldrich Library of Chemical Safety Data, Sigma-Aldrich Coporation,

G.Lunn and E.B.Sansone, Distruction of Hazardous Chemicals in the Laboratory, Wiley-Interscience

G.M.Muir (ed.), Hazards in the Chemical Industry, 2nd edn, The Royal Society of Chemistry, London,

A.Pocot and P.Grenouillet, Safety in the Chemistry and Biochemistry Laboratory, VCH Publ. Inc.,

D.A.Pipitone, Safe Storage of Laboratory Chemicals, J.Wiley & Sons Inc., NY, 1984. Prudent Practices for Handling Hazardous Chemicals in Laboratories, National Academy Press,

N.I.Sax, Dangerous Properties of Industrial Materials, 8th edn, Van Nostrand Reinhold, NY, 1992. N.I.Sax and R.J.Lewis, Hazardous Chemicals Desk Reference, Van Nostrand, Reinhold, NY, 1987. N.V.Steere (ed.), CRC Handbook of Laboratory Safety, CRC Press, Florida, 1971. Occupational Safety and Health Administration, OSHA Regulated Hazardous Substances (Health,

R.E.Lenga, The Sigma-Aldrich Library of Chemical Safety Data, 2nd Edn, (2 volumes), Sigma Aldrich

London, 1973.

Milwaukee, W1, 1986.

Publ., NY, 1990.

1977.

Weinheim, 1995.

Washington, D.C., 1983.

Toxicity, Economic and Technical Data), Noyes Data Corp., Park Ridge NJ, 1990.

Corp. 1988.

Solvents, Solvent Extraction and Distribution

L.C.Craig, D.Craig and E.G.Scheibe1, in A. Weissberger's (ed) Techniques of Organic Chemistry, vol

D.R.Lide, Handbook of Organic Solvents, CRC Press, Florida, 1995. F.A.von Metzsch, in W.G.Berl's (ed), Physical Methods in Chemical Analysis, vol IV, Academic Press,

B.Y.Zaslavsky, Aqueous Two-Phase Partitioning, M.Dekker Inc., NY, 1994.

111, pt I, 2nd edn, Interscience, NY, 1956.

NY, 1961.

Thin Layer Chromatography

B.Fried and J.Sherma, Thin Layer Chromatograpgy, M. Dekker Inc., NY, 1994. H.Jork, W.Funk, W.Fischer and H. Wimmer, Thin Luyer ChromAtography (3 volumes) VCH, Publ.

A.Zlatkis and R.E.Kaiser (eds), High Performance Thin Luyer Chromatography, Elsevier, Amsterdam, Inc., NY, 1992.

1977.

Zone Refining

E.F.G.Herington, Zone Melting of Organic Compounds, Wiley & Sons, NY, 1963. W.Pfann, Zone Melting, 2nd edn, Wiley, NY, 1966. H.Schildknecht, Zonenschmelzen, Verlag Chemie, Weinheim, 1964. W.R.Wilcox, R.Friedenberg et al., Chem.Rev., 64 187 1964. M.Zief and W.R.Wilcox (eds), Fractional Solidification, vol I , M Dekker Inc., NY, 1967.

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