Evaluation of weighted discriminating power calculations as an aid to the selection of chromatographic systems for the analyses of drugs

Drug screening in biological fluids. The need for a systematic approach

In this paper the key steps towards drug screening in biological fluids are considered: (i) sample work up-isolation-concentration; (ii) differentiation-detection; (iii) identification. For (i) solid-phase extraction has very good potential; for (ii) thin-layer chromatography, gas chromatography and high-performance liquid chromatography, in combination with their respective detection modes, each have their particular advantages and disadvantages; for (iii) extensive computerized data bases are essential. It is emphasized that each step must be approached and carried out in a systematic way, not only to make sure that all substances of interest can be detected, but also for their correct identification. To this end all analytical procedures and techniques used require extensive validation of their detection and identification properties.

Reversed-phase high-performance liquid chromatographic database of retention indices and UV spectra of toxicologically relevant substances and its interlaboratory use

An HPLC identification system based on a 1-nitroalkane retention index scale and secondary retention index standards is described. The retention index values and spectral data for 383 toxicologically relevant compounds (therapeutic and illicit drugs, environmental toxins and endogenous compounds) are given. The retention data may be directly applied in any laboratory using any reversed-phase, base-deactivated column, provided that the standardized procedure is observed.

Use of dual-column fused-silica capillary gas chromatography in combination with detector response factors for analytical toxicology

Retention and detector response factor data have been given for 188 compounds on the DB1 capillary column using a dual nitrogen--phosphorus and flame ionization detection system. Factors affecting the detector response factor parameter in a dual-capillary column system have been discussed showing its advantage in drug screening.

Chromatography in analytical toxicology — state of the art and future perspectives

The aims of systematic toxicological analysis are considered with respect to the principal techniques available for quantitative and qualitative purposes. The use of thin-layer (TLC), gas-liquid (GLC), capillary GLC and high-performance liquid chromatography (HPLC) is discussed, with special reference to the need for standardized systems for toxicological analysis. The selectivity of correlations presented as mean list length values, derived from archives of Kováts retention indices in GLC and of Rf-values in up to eight TLC systems, is illustrated by some typical examples. The dependence of Kováts retention indices on column packing materials and on load capacity in CGLC is discussed and the particular difficulties of comparable standard systems in HPLC are considered. Conclusions are drawn concerning the established 'workhorse' techniques, such as TLC and GLC. The need to adapt and standardize other powerful analytical methods, such as HPLC, MS and GLC-MS, is examined with regard to the requirements of toxicological analysis.