Propoxyphene and norpropoxyphene quantitation in the same solid-phase extraction using Toxi-Lab Spec VC MP3 system

Determination of dextropropoxyphene and nordextropropoxyphene in urine by liquid chromatography-electrospray ionization mass spectrometry

Dextropropoxyphene and nordextropropoxyphene were extracted from urine samples with mixed mode solid-phase extraction cartridges. After elution and evaporation to dryness, the eluate was dissolved in mobile phase and each sample was injected in a LC-ESI-MS system. Quantification was carried out in the selected ion monitoring mode. This article shows the possibility to analyse drugs of abuse substances in urine with a single quadrupole mass spectrometer if only a thorough work-up procedure and a sufficient chromatographic separation is accomplished. In order to enhance the fragmentation of the analytes, in-source fragmentation was carried out. One fragment and the pseudomolecular ion per analyte together with chromatographic retention times were sufficient to verify that the sought compound was found in the samples. In- and between day variation was lower than 10% and the recovery was well above 90%. The analytes were quantified in the range 100-10000 ng/ml urine.

Gas chromatographic-mass spectrometric quantitation of dextropropoxyphene and norpropoxyphene in hair and whole blood after automated on-line solid-phase extraction. Application in twelve fatalities

After conversion of norpropoxyphene (NP) to its corresponding amide, dextropropoxyphene (DP) and NP are extracted from 1 ml of blood or 50 mg of powdered hair, on C18 cartridges and eluted using methanol containing 0.5% acetic acid. Automated extraction is conducted on-line with automated device, starting from buffered and centrifuged sample. After extraction, the dried residue is reconstituted with 40 microl of methanol, and then injected in a gas chromatograph at 250 degrees C. Quantitation is carried out by gas chromatography-mass spectrometry in the selected-ion monitoring mode, lidocaine being the internal standard. The method gave relative standard deviations lower than 6.2% in whole blood, and 6.0% in hair for the entire range of calibration from 0.5 to 10 microg/ml in blood and from 1 to 20 ng/mg in hair of both compounds. Limits of detection in blood and hair for DP are, respectively, 0.07 microg/ml and 0.05 ng/mg, whereas the respective limits of detection in whole blood and hair for NP are 0.09 microg/ml and 0.04 ng/mg. The present method was used for one year in our laboratory. Postmortem concentrations of DP in blood ranged from 1.6 to 44.0 microg/ml (mean=9.8microg/ml, n = 12) and are comparable to those found in the literature. Out of 30 hair samples from people who died from heroin overdose, 13 were positive both for DP and NP with concentrations ranging from 0.2 to 27.4 ng/mg (mean 8.7 ng/mg) for DP and 0.3 to 68.9 ng/mg (mean 24.1 ng/mg) for NP.

Clinical evaluation of Toxi · Prep™: a semiautomated solid-phase extraction system for screening of drugs in urine

A prototype Toxi · Prep (TP) system that utilizes solid-phase extraction (SPE) has been developed as a method for broad-spectrum drug screening and identification of tetrahydrocannabinol (THC) metabolites in urine. TP can simultaneously extract up to seven specimens while automating the process of sample extraction, washing, and elution onto a chromatogram. TP was compared with the Toxi · Lab A (TL-A) system for extraction of basic drugs only. In a blind study, 33 distinct drugs and metabolites were detected in 55 urines over 13 runs. Of the drug occurrences, 68.8% (141 of 205) were detected on both TP and TL-A. Of the 13 runs, quinidine and quinine, nortriptyline metabolites, and diphenhydramine were noted more frequently on TP than TL-A, whereas nicotine and metabolites, morphine, and methadone metabolites were more frequently noted on TL-A. Twenty specimens were analyzed for THC metabolites. Of the cases positive for THC metabolites, 100% (16 of 16) were positive by both methods. Time and motion studies for all runs proved an overall labor reduction for extraction and spotting by ∼40%.

Screening for drugs of abuse (II): Cannabinoids, lysergic acid diethylamide, buprenorphine, methadone, barbiturates, benzodiazepines and other drugs

Requirements for the provision of an efficient and reliable service for drugs of abuse screening in urine have been summarized in Part I of this review. The requirements included rapid turn-around times, good communications between requesting clinicians and the laboratory, and participation in quality assessment schemes. In addition, the need for checking/confirmation of positive results obtained for preliminary screening methods was stressed. This aspect of the service has assumed even greater importance with widespread use of dip-stick technology and the increasing number of reasons for which drug screening is performed. Many of these additional uses of drug screening have possible serious legal implications, for example, screening school pupils, professional footballers, parents involved in child custody cases, persons applying for renewal of a driving licence after disqualification for a drug-related offence, doctors seeking re-registration after removal for drug abuse, and checking for compliance with terms of probation orders; as well as pre-employment screening and work-place testing. In many cases these requests will be received from a general practitioner or drug clinic with no indication of the reason for which testing has been requested. This also raises the serious problems of a chain of custody, provision of two samples, stability of samples, and secure and lengthy storage of samples in the laboratory-samples may be requested by legal authorities several months after the initial testing. The need for confirmation of positive results is now widely accepted but it may be equally important to confirm unexpected negative results. Failure to detect the presence of maintenance drugs may lead to the patient being discharged from a drug treatment clinic and, if attendance at the clinic is one of the terms of continued employment, to dismissal. It seems likely that increasing abuse of drugs and the efforts of regulatory authorities to control this, will lead to the manufacture of more designer drugs. Production of substituted phenethylamines was facilitated by the drug makers' cook book, 'PIHKAL' (Phenethylamines I Have Known And Loved) by Dr Alexander Shulgin and Ann Shulgin, and production of substituted tryptamines is promised in their next book, TIHKAL. Looking to the future, laboratories will need to ensure that they can detect and quantitate an ever-increasing number of drugs and related substances. The question of confidence in results of drugs of abuse testing raised in 1993 by Watson has assumed even greater importance as a result of attention focused on the OJ Simpson trial in Los Angeles. Toxicological investigations are likely to be challenged more frequently in the future. Even if analyses have been performed by GC-MS, there is a need to establish the level of match between the spectrum of the unknown substance and a library spectrum which is considered acceptable for legal purposes. It will also be essential to ensure that computer libraries contain spectra for all substances likely to be encountered in drugs of abuse screening.