[Retention indices for gas chromatographic identification of drugs (authors transl)]

Detection of anticonvulsants and their metabolites in urine within a "general unknown" analysis procedure using computerized gas chromatography-mass spectrometry

Detection of the anticonvulsants carbamazepine, clonazepam, diazepam, ethosuximide, mephenytoin, mesuximide, methylphenobarbital, phenobarbital, phenytoin, primidone, propylhexedrine, sultiame, trimethadion and their metabolites in urine is described. The method presented is integrated in a general screening procedure (general unknown analysis) for several groups of drugs, detecting several hundred drugs and over 1000 metabolites. It includes cleavage of conjugates by acid hydrolysis, isolation by liquid-liquid extraction, derivatization by acetylation, separation by capillary gas chromatography and identification by computerized mass spectrometry. Using mass chromatography with the selective ions m/z 58, 104, 113, 117, 165, 193, 204 and 246, the possible presence of anti-convulsants and/or their metabolites was indicated. The identity of positive signals in the reconstructed mass chromatograms was confirmed by a visual or computerized comparison of the stored full mass spectra with the reference spectra. The sample preparation, mass chromatograms, reference mass spectra and gas chromatographic retention indices are documented.

Identification of antiarrhythmic drugs and their metabolites in urine

Identification of the antiarrhythmic drugs ajmaline, aprindine, diltiazem, disopyramide, flecainide, gallopamil, lidocaine, lorcainide, mexiletine, phenytoin, prajmaline, propafenone, quinidine, sparteine, tocainide and verapamil and their metabolites in urine is described. After acid hydrolysis of the conjugates, extraction and acetylation, the urine samples were analysed by computerized gas chromatography-mass spectrometry. Using ion chromatography with the selective ions m/z 58, 72, 84, 86, 136, 224, 266, and 426, the possible presence of antiarrhythmic drugs and/or their metabolites was indicated. The identity of positive signals in the reconstructed ion chromatograms was confirmed by a visual or computerized comparison of the stored full mass spectra with the reference spectra. The ion chromatograms, reference mass spectra and gas chromatographic retention indices (OV-101) are documented. The method presented is integrated in a general screening procedure (general unknown analysis) for several groups of drugs.

Modern chromatographic procedures in systematic toxicological analysis

The fact that the toxicologist in systematic toxicological analysis never knows what he is looking at but has to take into account a vast number of toxicologically relevant substances makes this field a very difficult, yet challenging task. Because of the strong qualitative emphasis gas and thin-layer chromatography are at present the techniques of choice, and can be used with other relevant techniques such as spray reactions on the plate, UV spectrophotometry and mass spectrometry. However, as a single chromatographic technique will never provide unequivocal identification, the techniques have to be used side by side, so that the final identification matches the results from all the techniques applied. This approach requires that the advantages and disadvantages of each technique be well-known so that a combination of techniques can be chosen that provides the optimum identification power. After the unknown substance(s) have been analysed by a number of techniques and their particular behaviour in these techniques has been established, these findings are then matched against a data bank containing the behaviour of reference substances. This data bank should be as large as possible. Moreover, the search process used with the data bank must take into account the identification power of each individual technique, otherwise a well balanced "yes-no" decision about the presence or absence of a given substance is impossible.

Identification of phenothiazine antihistamines and their metabolites in urine

Identification of the phenothiazine antihistamines alimemazine, dimetotiazine, isothipendyl, mequitazine, oxomemazine, promethazine, thiethylperazine, triflupromazine and their metabolites in urine is described. After acid hydrolysis of the conjugates, extraction and acetylation the urine samples were analysed by computerized gas chromatography-mass spectrometry. Using ion chromatography with the selective ions m/z 58, 72, 100, 114, 124, 128, 141, and 199 the possible presence of phenothiazine antihistamines and/or their metabolites was indicated. The identity of positive signals in the reconstructed ion chromatograms was confirmed by a visual or computerized comparison of the stored full mass spectra with the reference spectra. The ion chromatograms, reference mass spectra and gas chromatographic retention indices (OV-101) are documented. The procedure presented is integrated in a general screening procedure (general unknown analysis) for several groups of drugs.

Separation and identification of illicit heroin samples by liquid chromatography using an alumina and C18 coupled column system and photodiode array detection

The analysis of illicit heroin and opium samples on a coupled alumina and C18 column system is described. The compounds to be analysed can be divided into two groups: those with low pKa values, such as caffeine, papaverine and noscapine, and those with high pKa values, such as heroin, acetylcodeine, O6-monoacetylmorphine, procaine, codeine, morphine and strychnine. The first group can best be separated on a C18 column, whereas alumina is more suitable for the second group. Previously reported criteria for choosing proper buffer systems for ion-exchange separations on alumina were used together with an iterative regressive optimization procedure developed in our laboratory. The system can be used with and without valve-switching, depending on the sample type. The peak purity of the judicially important components heroin and O6-monoacetylmorphine has been checked with a photodiode array detector and by use of advanced software.

Gas-liquid chromatographic retention indices of 1318 substances of toxicological interest on SE-30 or OV-1 stationary phase

Retention indices associated with 1318 substances likely to be encountered in toxicological analyses are presented. They are listed in ascending order of retention index for identification purposes and also in alphabetical order of compound name. The 4586 values used in this collection have been extracted from 36 sources, many of which have not been previously published. In many cases, where the quoted retention index is the mean of several determinations, the reproducibility and reliability of this value may be assessed. A histogram of the 1742 values listed is provided to help in determining the usefulness of a retention index for identification purposes. The reproducibility of inter-laboratory retention index measurements for twenty compounds on both SE-30 and OV-17 are presented and show the former, on average, to give more reproducible results.

[The detection of guaiacol glyceryl ether, a content of many sedatives and hypnotics in the Federal Republic of Germany]

Guaiacol Glyceryl Ether (GGE) is well known as an expectorant in a large number of cough syrups etc. More recently it was used in surgery because of its activity as a muscle relaxant and its additive effect on narcotics. Today many of the sedatives and hypnotics in the BRD, which are available without prescription, contain GGE in doses of 50 mg to 250 mg partially combined with other sedative acting substances. With regard to the abuse of sedatives and hypnotics GGE therefore will be more important in future. The analytical data of GGE (for details see key words), extraction behavior and identification of TLC combined with quantitative determination by HPLC are described.

Gas--liquid chromatographic retention indices of 296 non-drug substances on SE-30 or OV-1 likely to be encountered in toxicological analyses

The advent of the widespread use of selective detectors (electron capture detector, phosphorus/nitrogen dectector) for gas--liquid chromatography used in toxicological analyses has revealed the presence of hitherto unseen interfering materials. These substances may be conveniently grouped into (1), anti-oxidants; (2), putrefactive and endogenous compounds; (3), pesticides; (4), food additives, flavours and fragrances; (5) plasticisers, plastic additives and vulcanising agents and (6), scintillation reagents. To facilitate the identification of these materials, retention indices on the dimethyl silicone phases SE-30 or OV-1 have been compiled by the two laboratories to include 296 such compounds. Most gave single peaks, but some gave complex patterns indicating that they were mixtures of compounds. Of the 296 compounds, 14 did not give observable peaks, 8 gave 2 or 3 peaks and 44 gave more than 3 peaks. To determine the interlaboratory difference between retention index measurements, 17 compounds were chromatographed by both laboratories: the mean difference was +/- 13 retention index units with only one greater than +/- 50 retention index units. Examples of how these materials may be encountered during toxicological analyses are given. Data are also presented on compounds which have been used as internal standards.

[GLC-data of 19 hydrolysis-derivatives rised from 12 important benzodiazepines and 17 main-metabolites (author's transl)]

Analytical investigations of extracts after acid hydrolysis are in use especially considering benzodiazepine screening methods. The article describes the gas-chromatographic data of 19 hydrolysis-derivatives which are formed by hydrolysis of 12 important 1,4- and 1,5-benzodiazepines and 17 main metabolites.