SCREENING FOR DRUGS IN SERUM AND URINE BY LC / ESI / CID-MS AND MS / MS WITH LIBRARY SEARCHING
A mass spectra library using in-source collision induced dissociation (ESI/CID) as well as a MS/MS library with product ion spectra of ca. 500 drugs have been developed with a triple-quadrupole ionspray mass spectrometer. For the ESI/CID MS library single quadrupole mode and for the MS/MS library triple-quadrupole mode were used. The libraries have been used for general-unknown screening and for identification of drugs and metabolites in serum and urine.
Fragmentation of toxicologically relevant drugs in positive-ion liquid chromatography-tandem mass spectrometry.
The identification of drugs and related compounds by LC-MS-MS is an important analytical challenge in several application areas, including clinical and forensic toxicology, doping control analysis, and environmental analysis. Although target-compound based analytical strategies are most frequently applied, at some point the information content of the MS-MS spectra becomes relevant. In this article, the positive-ion MS-MS spectra of a wide variety of drugs and related substances are discussed. Starting point was an MS-MS mass spectral library of toxicologically relevant compounds, available on the internet. The positive-ion MS-MS spectra of ∼570 compounds were interpreted by chemical and therapeutic class, thus involving a wide variety of drug compound classes, such benzodiazepines, beta-blockers, angiotensin-converting enzyme inhibitors, phenothiazines, dihydropyridine calcium channel blockers, diuretics, local anesthetics, vasodilators, as well as various subclasses of anti-diabetic, antidepressant, analgesic, and antihistaminic drugs. In addition, the scientific literature was searched for available MS-MS data of these compound classes and the interpretation thereof. The results of this elaborate study are presented in this article. For each individual compound class, the emphasis is on class-specific fragmentation, as discussing fragmentation of all individual compounds would take far too much space. The recognition of class-specific fragmentation may be quite informative in determining the compound class of a specific unknown, which may further help in the identification. In addition, knowledge on (class-specific) fragmentation may further help in the optimization of the selectivity in targeted analytical approaches of compounds of one particular class.
Solid Phase Extraction of Abused Drugs.
: The current standard for acceptable practice in forensic urine drug testing, as reflected in both National Institute for Drug Abuse (NIDA) and military guidelines, requires an initial immunoassay followed by gas chromatography/mass spectrometry (GC/MS) confirmation. The GC/MS confirmatory procedures mandate extraction of the drug from the urine matrix, followed in most cases by chemical derivatization, prior to injection into the gas chromatograph. Classically, the extraction step has been accomplished using liquid-liquid techniques, but in recent years, the use of solid phase chromatographic techniques has become increasingly popular. Numerous companies now market solid phase columns that are designed specifically for extraction of drugs, some of them containing as many as three different components for extracting acidic, basic, and neutral drugs. A survey of NIDA laboratories, conducted specifically for this review article, revealed that 40 to 50% of the extraction procedures currently performed involved the use of solid phase cartridges. This article reviews chromatographic separation techniques in general, specific products that are currently available on the market, the performance of those products, and examines the results of the survey of NIDA-certified laboratories.