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As you may have already noted, this year introduces a new set of authors for this fundamental review. As new authors, they hope that they can do as accurate a job as did their predecessor, Professor Earl Wehry, of the University of Tennessee. The format for this review follows the basic outline used by Professor Wehry, with some modifications. They have condensed several sections and eliminated the section on gas-phase chemiluminescence. The primary areas of emphasis including advances in experimental techniques, developments in instrumentation, and applications for chemical analysis, remain the same. To keep the review at a reasonable length, they have not included articles that are only peripherally related to analytical chemistry or those that represent straightforward extensions or demonstrations of previously published research. In this first issue, it is likely that they have made some errors of omission, and they request your assistance in identifying any obvious errors. They have tried to be conscientious in surveying the literature and have also surveyed individual researchers in the field. This review covers literature indexed by Chemical Abstracts from January, 1985, Vol. 102, issue 1, through October 1987, Vol. 107, issue 16. Accordingly, there will be some overlap between this reviewmore » and Professor Wehry's last review.« less

Dipeptide micelle polymers are a new class of polymeric surfactants of which the polysodium undecanoyl-L-leucylvalinate (poly-L-SULV) was found to be a broadly applicable chiral selector for micellar electrokinetic chromatography. This negatively charged dipeptide micelle polymer is a high molecular weight compound with large countercurrent mobility, zero critical micelle concentration, low aggregation number, and high solubility in water or water-organic solvents. In an extensive chiral screening program, enantioseparation of 75 racemic compounds was tested with poly-L-SULV as chiral pseudostationary phase in neutral pH and basic pH background electrolytes. A total of 58 out of 75 racemic compounds could be resolved after choosing an appropriate concentration of poly-L-SULV. Although anionic chiral analytes are difficult to resolve using poly-L-SULV, the percent success rate for chiral resolution of cationic (77%) and neutral (85%) racemates was very high. Aspects regarding electrostatic, steric, hydrophobic, and hydrogen-bonding interactions of this dipeptide micelle polymer with various classes of chiral analytes are discussed.

A colloidal graphite-coated emitter is introduced for sheathless capillary electrophoresis/nanoelectrospray ionization time-of-flight mass spectrometry (CE/ESI-TOFMS). The conductive coating can be produced by brushing the capillary tip to construct a fine layer of 2-propanol-based colloidal graphite. The fabrication involves a single step and requires less than 2 min. Full cure properties develop in approximately 2 h at room temperature and then the tip is ready for use. The coated capillary tip is applied as a sheathless electrospray emitter. The emitter has proven to bear stable electrospray and excellent performance for 50 microm i.d. x 360 microm o.d. and 20 microm i.d. x 360 microm o.d. capillaries within the flow rate of 80-500 nL/min; continuous electrospray can last for over 200 h in positive mode. Baseline separation and structure elucidation of two clinically interesting basic drugs, risperidone and 9-hydroxyrisperidone, are achieved by coupling pressure-assisted CE to ESI-TOFMS using the described sheathless electrospray emitter with a bare fused-silica capillary at pH 6.7. It is found that the signal intensity of m/z in sheathless CE/ESI-TOFMS at pH 6.7 is approximately 50 times higher than that at pH 9.0 for the two analytes, although the electroosmotic flow (EOF) at pH 9.0 provides sufficient flow rate (approximately 150 nL/min) to maintain electrospray.