Experimental design for optimization of microwave-assisted extraction of benzodiazepines in human plasma.

A simple and fast microwave-assisted-extraction (MAE) method has been evaluated as an alternative to solid-phase extraction (SPE) for the determination of six benzodiazepines widely prescribed in European countries (alprazolam, bromazepam, diazepam, lorazepam, lormetazepam and tetrazepam) in human plasma. For MAE optimization a Doehlert experimental design was used with extraction time, temperature and solvent volume as influential parameters. A desirability function was employed in addition to the simultaneous optimization of the MAE conditions. The analysis of variance showed that the solvent volume had a positive influence on the extraction of all the analytes tested, achieving a statistically significant effect. Also, the extraction time had a statistically significant effect on the extraction of four benzodiazepines. The selected MAE conditions-89 degrees C, 13 min and 8 mL of chloroform/2-propanol (4:1, v/v)-led to recoveries between 89.8 +/- 0.3 and 102.1 +/- 5.2% for benzodiazepines using a high performance liquid chromatography method coupled with diode-array detection. The comparison of MAE and SPE shows better results for MAE, with a lower number of steps in handling the sample and greater efficiency. The applicability of MAE was successfully tested in 27 plasma samples from benzodiazepine users.

Cocaine and opiates use in pregnancy: detection of drugs in neonatal meconium and urine.

In this study, the case of a newborn with symptoms of hyperexcitability was analyzed. After it was confirmed in the hospital that the mother had consumed drugs during pregnancy using an enzyme multiplied immunoassay technique, samples of the newborn's urine and meconium were sent to our laboratory to observe the evolution in the distribution of cocaine and opiates during the days following birth. For urine analysis, screening was done with an immunoassay technique, and the confirmation was done by gas chromatography-mass spectrometry (GC-MS) according to a published method. A GC-MS method for simultaneous analysis of cocaine, benzoylecgonine, codeine, morphine, and 6-acetylmorphine in meconium is described. GC-MS confirmation of urine and meconium results showed consumption of cocaine and codeine during pregnancy and also showed the levels of drugs gradually declined, totally disappearing by the third day.

Prenatal alcohol exposure and its repercussion on newborns.

BACKGROUND: Alcohol consumption during pregnancy, even when moderate, implies a risk of impaired neurodevelopment, physical impairments and malformations. Its early identification is essential for establishing preventive measures to diminish disabilities among newborns. METHODS: To determine the frequency of consumption of substance use in pregnant women, we have used the techniques of gas chromatography/mass spectrometry and liquid chromatography/tandem mass spectrometry to detect drugs and markers of chronic consumption of alcohol in meconium. We performed a prospective study during a period of 10 months among 110 infants in our hospital, assessing anthropometry, neuromuscular development and determination of toxic substances in urine and meconium. Furthermore, meconium analysis identified fatty acid ethyl esters (FAEEs) and ethyl glucuronide (Etg). We also conducted a survey regarding the obstetric history, toxic habits, and employment status of the mothers. RESULTS: According to early detection markers analyzed in meconium (FAEE >1000 ng/g and/or Etg >50 ng/g meconium), 34.65% of pregnant women consumed alcohol during pregnancy, and 17% were positive for both markers. Within the positive cases, 50% of those exceeding a FAEE's value of 5000 ng/g in meconium had low birth-weight children. Only 5/110 mothers (4.5%) admitted to occasional alcohol consumption during pregnancy. Nobody admitted to frequent intake. The cocaine test was positive in three cases; two of them were positive for alcohol as well. CONCLUSION: As expected, many screening devices do not accurately capture use during pregnancy and supplemental methods such as meconium analysis of biomarkers of chronic alcohol consumption may be warranted.

Analysis of six benzodiazepines in vitreous humor by high-performance liquid chromatography-photodiode-array detection.

The purpose of this study was to validate a high-performance liquid chromatography-photodiode-array detetion method for the determination of six benzodiazepines in vitreous humor. The sample preparation was carried out using solid-phase extraction with Oasis HLB cartridges and 10% acetic acid/MeOH as elution solvent. The vitreous humor is less affected by postmortem changes and is a very useful sample when blood or urine specimens are not available. Linear curves for bromazepam, alprazolam, lorazepam, lormetazepam, diazepam, and tetrazepam were obtained within the range 0.03-3 µg/mL, with coefficients of correlation lower than 0.999. The limit of detection was 3 ng/mL, and the lower limit of quantification was 30 ng/mL for each benzodiazepine. Intra- and interassay for precision and accuracy provided results less than 16.81% and 16.78%, respectively. Recoveries were higher than 68.51% in all cases. Finally, the method was applied to determine benzodiazepines in vitreous humor from intoxicated patients.