Determination of flunitrazepam and 7-aminoflunitrazepam in human urine by on-line solid phase extraction liquid chromatography–electrospray-tandem mass spectrometry

Fuh, Ming‐Ren; Lin, Shieh-Shing; Chen, Li-Lung; Lin, Tzuen-Yeuan

doi:10.1016/j.talanta.2007.01.040

Cited by 32 publications

(20 citation statements)

References 25 publications

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“…Our sensitivity of urine benzodiazepines is superior or equal to the previous results [24,26–28]. Our LOQ of flunitrazepam (2 ng/mL) was similar to that of a previous study [27].…”

Section: Discussionsupporting

confidence: 88%

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Simultaneous identification of abused drugs, benzodiazepines, and new psychoactive substances in urine by liquid chromatography tandem mass spectrometry

Lee

Lin

et al. 2016

The Kaohsiung J of Med Scie

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A literature search reveals no studies concerning simultaneous identification of commonly abused drugs, benzodiazepines, and new psychoactive substances in urine by liquid chromatography tandem mass spectrometry (LC-MS/MS). We developed and validated an LC-MS/MS method for simultaneous identification of multiple abused drugs, benzodiazepines, and new psychoactive substances in urine from suspected drug abusers. The instrument was operated in multiple-reaction monitoring using an electrospray ionization mode. Chromatograms were separated using an ACE5 C18 column on a gradient of acetonitrile. After liquid-liquid extraction, samples were passed through a 0.22-μm polyvinylidene difluoride filter before injection into the LC-MS/MS. The limits of quantitation ranged from 0.5 ng/mL to 31.3 ng/mL. The linearity ranged from 0.5 ng/mL to 200 ng/mL. The precision results were below 15.4% (intraday) and 18.7% (interday). The intraday accuracy ranged from 85.9% to 121.0%; interday accuracy ranged from 66.1% to 128.7%. The proposed method was applied to 769 urine samples. The most common three drugs identified were ketamine, amphetamine, and opiates. The drug positive rate for one or more drugs was 79.6%. Our results demonstrate the suitability of the LC-MS/MS method for simultaneous identification of multiple abused drugs, benzodiazepines, and new psychoactive substances in urine.

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“…Our sensitivity of urine benzodiazepines is superior or equal to the previous results [24,26–28]. Our LOQ of flunitrazepam (2 ng/mL) was similar to that of a previous study [27].…”

Section: Discussionsupporting

confidence: 88%

“…Our within‐day and between‐day precisions for flunitrazepam and 7‐aminoflunitrazepam showed lower precision results data than that of Fuh et al. [26]. The accuracy performance in this study for flunitrazepam and 7‐aminoflunitrazepam was also similar to the studies of Fuh et al.…”

Section: Discussionsupporting

confidence: 84%

Simultaneous identification of abused drugs, benzodiazepines, and new psychoactive substances in urine by liquid chromatography tandem mass spectrometry

Lee

Lin

et al. 2016

The Kaohsiung J of Med Scie

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“…6 However, one of the challenges for the application of chromatography technology in TDM is the sample pretreatment. [10][11][12][13][14][15][16][17][18][19] A number of methods for the determination of these three analytes in biological uids by LC-MS/MS individually or in combination have been described 20-28 using conventional method such as protein precipitation, offline solid phase extraction and liquid-liquid extraction for sample pretreatment that were time-consuming, labor intensive and costly. To remove biological matrix, sample pretreatment is essential.…”

Section: Introductionmentioning

confidence: 99%

A simple and automated online SPE-LC-MS/MS method for simultaneous determination of olanzapine, fluoxetine and norfluoxetine in human plasma and its application in therapeutic drug monitoring

Fan

Shen

et al. 2015

RSC Adv.

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The olanzapine-fluoxetine augmentation strategy has been proved efficacious for treatment-resistant depression, psychotic depression and bipolar depression. To achieve efficient therapeutic drug monitoring (TDM), we develop an automated online SPE-LC-MS/MS method for the simultaneous quantification of olanzapine, fluoxetine and norfluoxetine in human plasma. After adding an internal standard of diphenhydramine and centrifugation, a 10 mL plasma sample was directly injected into the SPE cartridge. While the analytes were retained on the SPE cartridge, the endogenous materials were washed out by the loading solvent. Following the valve switching, the analytes were eluted from the SPE cartridge to the analytical column by gradient elution. The analytes were quantified using a triplequadrupole tandem mass spectrometer. Calibration curves were linear over the concentration range of 0.25-50.00 ng mL À1 for olanzapine, and 0.50-100.00 ng mL À1 for fluoxetine and norfluoxetine. The intra-and inter-day precisions were within 1.17% and 4.63%. And the accuracies were between 95.60% and 101.48%. The mean matrix effect was in the range of 90.35% to 99.89% and mean recovery was in the range of 90.35% to 96.99%. This method has been successfully applied to two Chinese schizophrenia patients. The online SPE-LC-MS/MS method allows sensitive and robust quantification of olanzapine, fluoxetine and norfluoxetine for routine TDM in clinic.

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“…Liquidliquid extraction [13], solid-phase extraction (SPE) [14][15][16], online SPE [17] and solid-phase microextraction [18] have usually been successfully employed. Different analytical methods have been effectively developed and established to both identify and quantify these compounds; relevant information on a selected number of BZD-based applications is presented in Table 1.…”

Section: Introductionmentioning

confidence: 99%

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

Fernández¹,

Vázquez²,

Lorenzo

et al. 2010

Anal Bioanal Chem

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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°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.

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Determination of flunitrazepam and 7-aminoflunitrazepam in human urine by on-line solid phase extraction liquid chromatography–electrospray-tandem mass spectrometry

Cited by 32 publications

References 25 publications

Simultaneous identification of abused drugs, benzodiazepines, and new psychoactive substances in urine by liquid chromatography tandem mass spectrometry

Simultaneous identification of abused drugs, benzodiazepines, and new psychoactive substances in urine by liquid chromatography tandem mass spectrometry

A simple and automated online SPE-LC-MS/MS method for simultaneous determination of olanzapine, fluoxetine and norfluoxetine in human plasma and its application in therapeutic drug monitoring

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

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