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The chromatographic behavior of acidic drugs in ion‐exchange liquid chromatography using a guanidino phase was analyzed in silico for developing a quantitative structure retention relationship in anion‐exchange liquid chromatography. The directly calculated molecular interaction energy values between an analyte and a model phase using molecular mechanics calculations, correlated with high precision with the capacity ratios of acidic drugs measured in ion‐exchange liquid chromatography. Retention order could be predicted based on the molecular interaction energy values using a model phase, even in ion‐exchange liquid chromatography with a pH controlled eluent. The measured capacity ratio at pH 7.4 correlated well with the human serum albumin binding affinity measured using a modified Hummer‐Dreyer method with purified human serum albumin.

Chromatographic behavior of basic compounds, including basic drugs, in ion‐exchange liquid chromatography was analyzed in silico to develop quantitative structure retention relationship models. The determination of molecular interaction energy values between an analyte and a model‐phase, determined using a direct molecular mechanics calculation, demonstrated that retention order could be predicted, even in ion‐exchange liquid chromatography with a pH controlled eluent.

A high selectivity analytical method for p‐hydroxymethamphetamine (pOHMA) in urine is presented. After extraction, the analyte was analyzed by high performance liquid chromatography with post‐column oxidation using potassium hexacyanoferrate(III) and sodium hydroxide to detect the fluorophor of pOHMA. The recovery of pOHMA is 86.5%, and the calibration curve for pOHMA is linear in the range of 5–75 µg/mL (r 2=0.997). The coefficients of variation determined for spiked samples are 2.2% for 10 µg/mL and 2.3% for 5 µg/mL pOHMA (each n=5), and the detection limit for pOHMA is 1 µg/mL (20 ng; S/N=3). Analysis for pOHMA in forensic samples is performed successfully, without interference from endogenous fluorophors, yielding concentrations in the appropriate range for methamphetamine abusers.

Dithiocarbamate fungicides react with luminol to produce an intense chemiluminescence in the presence of hexacyanoferrate(III) and hexacyanoferrate(II) in alkaline solution. Based on this fact, a simple and sensitive method for the determination of dithiocarbamate fungicides by reversed‐phase ion‐pair liquid chromatography with chemiluminescence was developed. The mancozeb and propineb of dithiocarbamate fungicides were able to be separated using 5 mM phosphate buffer (pH 7.5) contained 2.5 mM tetrabutylammonium hydrogen sulfate/methanol (75:25) in a short time. The proposed method could be applied to the analysis of vegetables spiked with dithiocarbamate fungicides.

An ab initio simulation of reversed‐phase liquid chromatography for phenolic compounds was developed using a molecular mechanics calculation in the CAChe™ program. The calculated molecular interaction energy values were well correlated with the log k values measured as molecular and ionized forms in reversed‐phase liquid chromatography. Molecular interaction in liquid chromatography can be quantitatively estimated from the energy values calculated by molecular mechanics using analytes and a model phase.

The retention factors of aromatic acids were predicted from their log P and pKa values in reversed-phase liquid chromatography in eluent at a given pH. The log P value, a modified CAChe-log P ™ and Vlog P ™, was calculated by computational chemical methods. The pKa values in this study were derived from partial charges of atoms by computational chemical methods instead of Hammett's equations. The precision of predicted retention factors was dependent on the accuracy of pKa values.

Glycated albumin in human serum was analyzed by solid-phase extraction and selective detection. One system with one solid-phase extraction column and a chemiluminescence detector facilitated rapid analysis. A second system with two solid-phase extraction columns and a fluorescence detector was a fast and stable analytical method compared to liquid chromatographic analysis. Both analytical systems were suitable for diagnostic analysis of glycated human serum albumin. These systems require 1 μL blood serum for analysis.