Development and validation of a single LC-MS/MS assay following SPE for simultaneous hair analysis of amphetamines, opiates, cocaine and metabolites.

The two major challenges in hair analysis are the limited amount of samples usually available and the low targeted concentrations. To overcome these limitations, a liquid chromatography-electrospray-tandem mass spectrometry method (LC-ESI-MS/MS) allowing the simultaneous analysis of 17 amphetamines (amphetamine, BDB, m-CPP, dexfenfluramine, DOB, DOM, ephedrine, MBDB, MDA, MDEA, MDMA, methamphetamine, methylphenidate, 4-MTA, norephedrine, norfenfluramine and PMA), 5 opiates (morphine, codeine, heroin, ethylmorphine, and 6AM), cocaine and 5 metabolites [ecgonine methyl ester (EME), benzoylecgonine (BZE), anhydroecgonine methyl ester (AME), cocaethylene, and norcocaine] has been developed. The validation procedure included linearity, intra-day and inter-day variability and accuracy for 5 days (5 replicates at 3 concentration levels). Proficiency studies were used to check the accuracy of the method. As a result, all amphetamines, opiates and cocaine derivatives were satisfactory identified by 2 MRM transitions in 15 min. Calibration curves were performed by a quadratic 1/X weighted regression. The calibration model fits from 0.05 to 10 ng/mg. The limits of detection (LODs) range between 0.005 and 0.030 ng/mg. Precision has been checked by intra-day and inter-day RSD, and associated relative bias, which were lower than 25% for the limits of quantifications (LOQs) and lower than 20% for the other levels tested. This method was routinely applied to hair samples: two positive results of adult drug addicts are presented.

Urinary determination of 2-isopropyl-4-methyl-6-hydroxypyrimidine in case of non fatal poisoning with diazinon.

We reported one non fatal case (42 month old boy) of intoxication with diazinon following accidental ingestion. Diazinon and three of its metabolites (2 common metabolites with other organophosphate pesticides: diethylphosphate and diethylthiophosphate; one specific metabolite: 2-isopropyl-4-methyl-6-hydroxypyrimidine) were determined in serum and in urine, respectively, using three liquid chromatography-tandem mass spectrometry methods. Diazinon was detected in serum while its metabolites were detected in urine. The concentrations of diazinon and its common metabolites were compared to concentrations previously described in literature in the same intoxication context and were discussed. The concentration of the specific metabolite was compared to concentrations highlighted in occupational exposure, because to the best of our knowledge, we reported here the first urinary concentration of this metabolite in an acute intoxication context.

Multi-center evaluation of analytical performance of the microparticle enzyme immunoassay for sirolimus.

OBJECTIVES: This study evaluated the analytical characteristics of the new Abbott microparticle enzyme immunoassay (MEIA) for sirolimus. DESIGN AND METHODS: The protocol consisted of nine sections: evaluation of antibody specificity, linearity, detection limit, quantification limit, endogenous interferents, exogenous interferents, precision, proficiency testing panel, and method comparison. RESULTS: The mean analytical detection limit was 0.68 microg/L. The sirolimus concentration corresponding to a total CV of 20% was 1.5 microg/L. Linearity of response was demonstrated across the dynamic range of the assay. Total precision (CVs) at QC control levels from 5 to 22 microg/L ranged from 5.7 to 12.6%. Assay standardization was found to be in good agreement with LC/MS/MS as compared with target values for spiked sirolimus proficiency samples from an international sirolimus proficiency testing program. Good correlations (R values) of the immunoassay were observed in comparisons to LC/MS/MS. R values tended to be lower in comparisons with LC/UV methods. Across both LC-based methods and all study sites, there was approximately 25% overall positive slope bias due to cross reactivity of the MEIA antibody to metabolites of sirolimus. The assay cross-reactivity to metabolites of sirolimus parent drug ranged from 6 to 63%. Assay interferences were minimal with the exception of hematocrit, which presented a negative relationship to measured sirolimus concentration. CONCLUSIONS: The MEIA demonstrated acceptable analytical characteristics for use for routine monitoring of sirolimus immunosuppressive therapy, and is a viable alternative to HPLC-based methods for sirolimus monitoring.

WITHDRAWN: Multi-center evaluation of analytical performance of the microparticle enzyme immunoassay for sirolimus.

The Publisher regrets that this article is an accidental duplication of an article that has already been published in Clin. Biochem. 39 (2006) 378-386, doi:10.1016/j.clinbiochem.2006.01.017. The duplicate article has therefore been withdrawn. This article has been withdrawn consistent with Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). The Publisher apologizes for any inconvenience this may cause.

[Rape drugs: pharmalogical and analytical aspects]. / Les substances de la soumission chimique: aspects pharmacologiques et analytiques.

Rape drugs or compounds used for chemical submission are current hot topics of numerous media based on a few well-documented identified cases. In the aim of considering the compounds potentially involved and subsequently the samples to collect and the toxicological analyses to perform, and according to the aggressor's viewpoint (victim submission and impunity of himself or herself), the characteristics of such compounds were drawn following the drug pharmacological properties. The compounds or therapeutic classes potentially used are numerous and diverse because the expected effects can be obtained by many neuropharmacological mechanisms or combinations of mechanisms. However, a few drugs (i.e. several benzodiazepines, and gamma-hydroxybutyrate) seem to be the ideal candidates owing to advantageous pharmacological properties (low blood concentrations, short elimination half-life) and practical ones (availability, galenic forms). It appears that the quality and precocity of biological specimen collection, the use of specific and sensitive analytical techniques, and the collaboration between the clinician and the toxicologist, are the essential keys for successful toxicological investigations when a case of chemical submission is suspected.

Utilisation de l'acide gamma-hydroxybutyrique (ghb) dans les rave-parties et pour la soumission chimique en france : mythe ou réalité?

Since many years gamma-hydroxybutyric acid (GHB) is presented as very popular in rave-parties and for bodybuilders. It seems to be a controversy between media coverage and the results of toxicological analysis done in high-level laboratories. In order to clarify this problem, we compiled the data of 6 laboratories. They used the same analytical method by GC/MS. Depending the laboratory, the limit of detection was 1-2 µg/mL and the limit of quantification was 2.5-5 µg/ mL. Two labs where looking for GHB in each forensic case (100 and 150 cases a year). Others labs performed GHB analysis only on specific request (each 10 cases a year). Mean time between ingestion of GHB and blood/urine sampling was 12-48 h. Mean time between sampling and analysis was much higher (a few hours to a few month. All samples were stored at +4°C. Only 3 cases were considered as positive (blood GHB : 165, 132 and 114 µg/mL, urine GHB : 7450 and 436 µg/ mL) They were admitted in an hospital EU. Interpreting results remains very difficult because GHB is endogenous, present in blood and urine, and its half-life is very short. One has to report only « positive ¼ GHB results when amounts are higher than 5 µg/mL in blood and 10 µg/mL in urine. Obviously, forensic toxicologists have to play a very important part in diagnosis of GHB intoxications and estimating its frequency. Actually, because the lack of data in France, it is not possible to answer the question asked in the title of this paper.

Nouvelles drogues de « rave-parties ¼ : ketamine et prolintane.

"Rave parties", all-night dance parties based on "techno" music, represent an increasing phenomenon in France. "Rave drugs" refers to a wide variety of drugs used by the young participants owing to their hallucinogenic or stimulant effects. Uncertainties about the sources of these substances, the possible contaminants and the multiplicity of the associations make it difficult to evaluate the toxic consequences that might be expected in this particular context. This report presents toxicological cases documented by analytical findings in which two pharmacological agents abused in "rave parties" in South-West of France were found. The day following a party, a 17 year-old girl showed a confused state with drowsiness and hallucinations. She confessed having consumed a white powder sold as "ecstasy", that sample analysis identified as pure ketamine. Ketamine is an anaesthetic agent primarily used in veterinary medicine and paediatrics. This drug seems to be abused, mainly by the intranasal route, owing to its hallucinogen effects. Its used in "rave-party" appears to be marked by unsuspected consumption. All long another party, a large quantity of orange tablets were sold and abused by several participants. Analysis performed on some fragments of these tablets revealed the presence of prolintane and ascorbic acid. Prolintane, an amphetamine-related substance, is a central nervous system stimulant. This compound is "freely" available in Spain in combination with several vitamins, under the form of tablets with orange coating named "Katovit" and sold at low price: 1.93 €/20 tablets (200 mg of prolintane).