8/2/2019 Strata-X General SPE Method

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S P E G P s trata-X

strata-X is a revolutionary, patent-pending polymeric s olid phase extraction (S P E ) s orbent. This simple, generalextraction method relies upon the unique polarity of the strata-X sorbent to retain a wide range of acidic, neutraland basic compounds from aqueous matrices by utilizing a combination of hydrophobic, hydrophilic and

retention mechanisms. It is designed to serve as a starting point and may be optimized for specific analytes.

Specimen preparation:

urine: dilute urine with an equal volume of 100mM phosphate buffer (pH = 6.0). Be aware that many compounds areexcreted as glucuronide metabolites from urine and may need hydrolysis.

plasma/serum: dilute 1:1 with deionized (DI) water or 100mM phosphate buffer (pH = 6.0). Be aware that the target compoundmaybe protein bound and may require an additional protein disruption step prior to extraction.

other aqueous s amples: adjust pH to 5.5-7.5.

P ha se : s urfa ce modifie d s tyrene -divinylbenz ene polyme r

P article s ize: 33m

P ore s ize: 85

S urface area: 800m2/g

pH stability: 1-14

Table 1. The physical and chemical characteristics of strata-X

The strataX Method

The volumes shown are for 30mg sorbent mass.

The strata-X method for general screening:

Conditionwith 1mL methanol

Equilibratewith 1mL D.I. water

Load Sample Wash Impuritieswith 1mL 5% methanol inD.I. water and dry 30 secat full vacuum

Elute Analyte!with 1mL methanol:ac etonitrile

Optimize the s trata-X method C omments

E nsure s the pH of the solution in the was h step is ke pt high so that the bas ic compoundremain neutralized, increasing their retention. This allows for aggressive clean-up ointerferences. The pH of the elution solvent is lowered by adding acid, facilitating the extractionof the a nalytes.

B asic compounds:Wash: 2% ammonium hydroxide in methanol/water (5:95)E lution:2% acetic acid in methanol/water (50:50)

Polar compounds:Wash: 10-20% ace tonitrile (or methanol) in water

E lution: methanol/ace tonitrile/water/acid (60: 30:10 :0. 1)

Optimizes the method for more aggressive clean-up of the interferences during the wash

step and to elute the stubborn, strongly retained polar analytes.

E nsure s the pH of the solution in the was h step is ke pt low so that the ac idic compoundremain neutralized, increasing their retention. This allows for aggressive clean-up ointerferences. Base is added to the elution solvent facilitating the extraction of the analytes

Acidic compounds:Wash: 2% acetic acid in methanol/water (5:95)E lution:2% ammonium hydroxide in methanol/water (50:50)

methanol / aceto

(1:1)