A rapid fluorimetric screening method for the 1,4-benzodiazepines: Determination of their metabolite oxazepam in urine

Tejedor, Ana; Hernando, Pilar Fernández; Alegría, Jesús

doi:10.1016/j.aca.2007.03.055

Cited by 20 publications

(17 citation statements)

References 24 publications

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“…The peak height increased up to a concentration of 3 mol L À1 and then fell as the HCl concentration further increased. In the previous study (Gil Tejedor et al 2007) carried on by our group in batch-wise mode, a similar result was obtained; in that case, the optimal HCl concentration was 8 mol L À1 in a studied range of 6-12 mol L À1 , which indicates that a lower HCl concentration is required when reaction is carried on on-line.…”

Section: Optimization Of the Methodssupporting

confidence: 76%

“…The method was applied to the chlordiazepoxide quality control (ACB impurity) since chlordiazepoxide did not react. Gil Tejedor et al (2007) studied the hydrolysis and subsequent cyclization of several benzodiazepines using Cerium (IV) as cyclization catalyst. The method was fast compared to those using lead dioxide and was able to detect benzodiazepines giving oxazepam as metabolite in urine after therapeutic administration.…”

Section: Analytical Performance and Urine Analysismentioning

confidence: 99%

“…The selectivity of the proposed method was previously studied by our group in batch-wise mode (Gil Tejedor et al 2007). Diazepam, flunitrazepam, nitrazepam, lorazepam, lormetazepam, bromazepam, tetrazepam, and clorazepate were submitted to the method and it was concluded that the selectivity was high; not only the benzodiazepines must give a benzophenone as hydrolyzed product, but also this benzophenone must have specific substitutes in some positions which prevents cross-reactivity from other metabolites presented in urine.…”

Section: Analytical Performance and Urine Analysismentioning

confidence: 99%

“…The proposed method is based on the molecular rearrangement of the hydrolysis product of oxazepam, 2-amino-5-chlorobenzophenone, to 2-chloro-9(10H)-acridinone, previously studied by our group in batch-wise mode (Gil Tejedor, Fernández Hernando, and Durand Alegría 2007). Reactions proceeded on-line using a flow injection analysis manifold.…”

Section: Introductionmentioning

confidence: 99%

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Study of On-Line Fluorimetric Determination of Oxazepam. Application to the Screening of 1,4-Benzodiazepines Giving Oxazepam as Metabolite in Urine

et al. 2013

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An automated, rapid, and sensitive flow injection method was developed for the fluorimetric determination of oxazepam and afterward applied for the screening of benzodiazepines with oxazepam as a common metabolite in urine. This method is based on the hydrolysis of oxazepam to the corresponding benzophenone and subsequent cyclization to form the fluorescent molecule 2-chloro-9(10H)-acridinone. Both reactions were allowed to proceed in a two channel flow injection manifold. The physical and chemical variables affecting the method were optimized and a linear calibration graph obtained. Oxazepam was detectable in the 40-700 ng mL À1 range. The detection limit of this method was 35 ng mL À1 for k ¼ 3 and the throughput was 25 samples h À1 . The method was successfully applied for the screening of oxazepam in urine samples collected at different times after the single oral administration of Valium and Tranxilium by two healthy volunteers.

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Section: Optimization Of the Methodssupporting

confidence: 76%

Section: Analytical Performance and Urine Analysismentioning

confidence: 99%

Section: Analytical Performance and Urine Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Study of On-Line Fluorimetric Determination of Oxazepam. Application to the Screening of 1,4-Benzodiazepines Giving Oxazepam as Metabolite in Urine

et al. 2013

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“…are a group of drugs with important clinical applications. They are widely prescribed as anxiolytic, hypnotic, anticonvulsant, myorelaxant, amnesic agents sleep regulator agents 1, 2. The major impact of these compounds operates widely in the brain, affecting emotional reactions, memory, thinking, muscle tone and coordination 3.…”

Section: Introductionmentioning

confidence: 99%

Multiwall Carbon Nanotube‐Ionic Liquid Modified Paste Electrode as an Efficient Sensor for the Determination of Diazepam and Oxazepam in Real Samples

et al. 2014

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A carbon‐based electrode using multiwall carbon nanotube as a modifier and room temperature ionic liquid as a binder has been applied for the determination of diazepam (DZP) and oxazepam (OZP) in real samples including serum, urine and tablets. Square wave voltammetry as an appropriate electrochemical technique was applied to achieve improved limits of detection and higher sensitivities. The electrochemical studies were investigated under various experimental conditions such as pH, buffer concentration, ionic strength, deposition potential, deposition time and scan rate to achieve higher sensitivities. Linear concentration ranges for DZP and OZP were 0.02–0.76 mg L−1 and 0.05–1.90 mg L−1 with the detection limits of 4.1 µg L−1 and 5.8 µg L−1, respectively. The proposed method was successfully applied for the analysis of commercially available tablets as well as serum and urine samples and satisfactory results were obtained.

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Applying cloud point extraction technique for the extraction of oxazepam from human urine as a colour or fluorescent derivative prior to spectroscopic analysis methods

Tabrizi

Harasi

2011

Drug Testing and Analysis

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Two new methods based on cloud point extraction (CPE) technique were developed and optimized for the extraction and preconcentration of oxazepam from human urine, as an azo or fluorescent derivative. The first method is a spectrophotometric one, which is based on the acid hydrolysis of the oxazepam to a benzophenone, diazotization of the benzophenone, and then the coupling with oxine to form an azo dye. The second method is a spectrofluorimetric one, which involves reduction of the target compound using Zn°/HCl at room temperature with the formation of a highly fluorescent derivative. The main factors affecting the chemical reactions and CPE were investigated and optimized systematically. Under optimum experimental conditions, the calibration graphs were linear in the range of 0.1 to 1.5 (0.05 to 2.0) µg/ml with correlation coefficients of 0.9989 (0.9985), for the CPE-spectrophotometric (CPE-spectrofluorimetric) method. The limit of detection was found to be 0.034 (0.018) µg/ml and the relative standard deviation was calculated to be 1.35 (2.52)%. Recoveries in the spiked samples ranged from 87 to 94%. Finally, the proposed methods were applied to the determination of oxazepam in human urine.

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A rapid fluorimetric screening method for the 1,4-benzodiazepines: Determination of their metabolite oxazepam in urine

Cited by 20 publications

References 24 publications

Study of On-Line Fluorimetric Determination of Oxazepam. Application to the Screening of 1,4-Benzodiazepines Giving Oxazepam as Metabolite in Urine

Study of On-Line Fluorimetric Determination of Oxazepam. Application to the Screening of 1,4-Benzodiazepines Giving Oxazepam as Metabolite in Urine

Multiwall Carbon Nanotube‐Ionic Liquid Modified Paste Electrode as an Efficient Sensor for the Determination of Diazepam and Oxazepam in Real Samples

Applying cloud point extraction technique for the extraction of oxazepam from human urine as a colour or fluorescent derivative prior to spectroscopic analysis methods

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