what do chemical information specialists, computer scientists, and chemists have in common?

THE NEWEST DEVELOPMENT IN

CAPILLARY COLUMNS! FOR INCREASED

SAMPLE CAPACITY WITH EXCELLENT

RESOLVING POWER, VERY THICK

FIVE MICRON BONDED FILMS

on

0 . 2 5 m m , 0 . 32mm and

NEW 0 . 5 3 m m I.D.

FUSED SILICA CAPILLARY COLUMNS

007' METHYL SILICONE (OV-1) and

007' METHYL 5% PHENYL SILICONE (SE-54) • HIGHEST SAMPLE CAPACITY

• HIGH SEPARATION EFFICIENCIES • ALL THE VIRTUES OF FUSED SILICA

• LONG LENGTHS AVAILABLE AVAILABLE EXCLUSIVELY FROM:

QUADREX CORPORATION P.O. Box 3881, New Haven, CT 06525

TEL: (203) 389-6620 Overseas: Quadrex Scientific, Box 79, Weybridge,

Surrey, KT 139 RA United Kingdom TEL: (093-22) 45848

See us at the 1984 PlttCon In Atlantic City on March Sth thru the 8th at

Booth No. 087 and 088

petitive, linear-mixed system, and hyperbolic-mixed system mechanisms quickly leads to the selection of the hyperbolic-mixed system as the most likely mechanism of the five consid­ered (Figure 12b). The residual sur­face deviations for the latter are equally distributed above and below the plane. A relative novice could in­terpret the data. Unlike the more tra­ditional techniques, all data were used in obtaining each set of parameter es­timates. To analyze the same data set by the traditional technique would have required the development and examination of hundreds of linear plots by a skilled kineticist.

Often it is desirable to obtain visual representations of the effects of four variables. This can be accomplished on a color terminal using transparen­cies. On a monochromic terminal one variable, e.g., the dependent variable, can be placed on the time axis, with the result that one sees a dynamic dis­play where each frame shows the rela­tionship of three independent vari­ables at a fixed level of the dependent variable. For the kinetics research de­scribed above, such a four-dimension­al representation was developed with a dynamic display of a reaction-rate surface as a function of three indepen­dent variables. Figure 13 shows three sequential frames from such a presen­tation, interactively displayed to the user in real time.

5 . 0 0

0 . 6 7

RATE

5 . 0 0

0 . 5 0 6 . 0 0

Figure 12. (a) Poor residual surface (un­competitive kinetic model); (b) good re­sidual surface (hyperbolic-mixed model)

CIRCLE 264 ON READER SERVICE CARD

318 A · ANALYTICAL CHEMISTRY, VOL. 56, NO. 2, FEBRUARY 1984