@article{3067139,
    title = "Direct urine analysis for the identification and quantification of selected benzodiazepines for toxicology screening",
    author = "Karampela, S. and Vardakou, I. and Papoutsis, I. and Dona, A. and Spiliopoulou, C. and Athanaselis, S. and Pistos, C.",
    journal = "Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences",
    year = "2012",
    volume = "902",
    pages = "42-46",
    doi = "10.1016/j.jchromb.2012.06.012",
    keywords = "Alprazolam;  Analytes;  Benzodiazepines;  Bromazepam;  Correlation coefficient;  Direct injection analysis;  False negatives;  Flunitrazepam;  High costs;  Human urine;  Immunoassay techniques;  Internal standards;  LC-MS/MS;  LC/MS;  Linear range;  Midazolam;  Minimal sample;  Oxazepam;  Positive mode;  Real samples;  Sample preparation;  Selected ion monitoring;  Sensitivity and specificity;  Toxicology screening;  Urine analysis;  Urine sample, Chemical analysis;  Direct injection;  Electrospray ionization;  Immunology;  Screening, Body fluids, 7 aminoflunitrazepam;  alprazolam;  benzodiazepine;  bromazepam;  diazepam;  flunitrazepam;  flurazepam;  midazolam;  nordazepam;  oxazepam;  temazepam, accuracy;  article;  drug urine level;  electrospray;  false negative result;  false positive result;  human;  immunoassay;  ion monitoring;  liquid chromatography;  mass fragmentography;  mass spectrometry;  measurement error;  priority journal;  sensitivity and specificity;  urinalysis, Benzodiazepines;  Chromatography, Liquid;  Gas Chromatography-Mass Spectrometry;  Humans;  Least-Squares Analysis;  Limit of Detection;  Linear Models;  Reproducibility of Results;  Sensitivity and Specificity;  Tandem Mass Spectrometry",
    abstract = "A simple and rapid LC/MS method with direct injection analysis was developed and validated for the identification and quantification of ten benzodiazepines (flunitrazepam, nordiazepam, diazepam, 7-aminoflunitrazepam, flurazepam, bromazepam, midazolam, alprazolam, temazepam and oxazepam) in human urine using diazepam-d5 as internal standard (IS). The main advantage of the proposed methodology is the minimal sample preparation procedure, as diluted urine samples were directly injected into LC/MS system. Electrospray ionization in positive mode using selected ion monitoring was chosen for the identification and quantification of the analytes. The linear range was 50-1000ng/mL for each analyte, with square correlation coefficient (r 2)≥0.981. Interday and intraday errors were found to be ≤5.72%. The LC/MS method was applied at ten real samples found initially to be positive and negative, using immunoassay technique. Finally the results were confirmed with GC/MS. The method demonstrates simplicity and fast sample preparation, accuracy and specificity of the analytes which make it suitable for replacement of immunoassay screening in urine avoiding thus false negative/false positive results. Using this method, laboratories may overcome the problem of high cost instrumentation such as LC-MS/MS by providing similar sensitivity and specificity with other methods. © 2012 Elsevier B.V.."
}