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A c c e p t e d m a n u s c r i p t AbstractThe objective of this study was to measure plasma cotinine levels in pregnant women and their newborns using a gas chromatography-mass spectrometry (GC-MS) method in an epidemiological delivered population with a wide range of tobacco intakes. Nearly one thousand pregnant women from regional maternity wards (n = 1007) were selected for the study. Each patient kept a tobacco diary and underwent a blood test to assess cotinine levels at the same time that newborns' cordonal plasma was taken. These values were then crosschecked.Cotinine was estimated using a selected-ion monitoring mode with a 1.5 ng/ml quantification limit. Cotinine levels in mothers and newborns were highly correlated, whatever the mother's smoking status with a calculated cut-off for cotinine levels in active smokers of 21.5 ng/ml. Finally, cotinine determined through this GC-MS method offered a sensitive and accurate measure of tobacco exposition of pregnant women and their babies.

The combined use of an automatic solid-phase extraction (SPE) apparatus with Oasis MCX cartridges and gas chromatography/mass spectrometry (GC/MS) to rapidly quantify quinine in biological samples with cyproheptadine as the internal standard is described. The selected ion monitoring mode, with the quantification ions m/z 136 and 287 (qualifier ions: m/z 261, 381 and 215, 96), allows the estimation of quinine levels, respectively. Separation was completed within 12.7 min. Excellent linearity was found up to 10 000 microg/L of plasma. The limit of detection (LOD) was 12.2 microg/L and the limit of quantification (LOQ) was 40.6 microg/L. High reproducibility (intra-assay CV range 1.9-4.3%, inter-assay CV range 2.2-11.3%) and accuracy values (intra-assay range 83.2-103.7%, inter-assay range 86.8-103.7%) were obtained. Recoveries were concentration-independent (97.2% and 89.8% for 4000 and 10 000 microg/L, respectively). This sensitive, simple assay for quinine in various matrices meets the current requirements for bioanalytical assays and may be used to monitor quinine levels in patients developing severe malaria with acute renal failure during hemofiltration. The optimal quinine dose in this situation is not really established and to improve clinical care, quinine concentrations might be explored to improve efficacy and minimise potential toxicity.

A rapid, sensitive, and ready-to-use gas chromatography-mass spectrometry method for meprobamate assay using carisoprodol as internal standard is described. The method involves extracting a 0.2-mL sample with chloroform, previously acidified with HCl 0.2N. For the quantitative analysis, we used selected-ion monitoring mode, selecting the ion m/z 144 for quantification of meprobamate and m/z 245 for carisoprodol. Excellent linearity was found between 0 and 200 mg/L plasma. The limit of detection was 0.58 mg/L, and the limit of quantification was 1.93 mg/L. A high reproducibility [intra-assay coefficient of variation (CV) range of 2.3-4.3% and interassay CV range of 5.5-12.3%] and accuracy (intra-assay range of 96.8-112.3% and interassay range of 85.5-99.3%) were observed. Recoveries were concentration-independent (87.0%, 76.2%, and 81.2% for 20, 75 and 150 mg/L, respectively). No interference from endogenous compounds, other metabolites of meprobamate, or frequently coadministered drugs was detected. This sensitive, simple assay for meprobamate in plasma, whole blood, and urine meets the current requirements for bioanalytical assays in overdose cases.