ABSTRACT
In China, some forensic cases are caused by barbiturates. Thus, the determination of trace level barbiturates in body fluid is important for the poisoning investigation. In this study, an online large-volume sample stacking (LVSS) with polarity switching in capillary electrophoresis (CE) was applied for the sensitive determination of barbiturates. This technique involves injecting a large volume of sample into a capillary and removing the sample matrix plug out of the capillary by reversing the polarity. Quantitation limit obtained was 0.048, 0.057, 0.039, and 0.015 µg/mL for secobarbital, amobarbital, barbital, and phenobarbital (signal-to-noise ratio = 9). By using LVSS, the stacking was simply achieved at 171.7-, 169.7-, 202.7-, and 169.1-fold for the above four barbiturates. The relative standard deviation values of intraday and interday were <2.11% and 4.69%, respectively. Recoveries were ranged from 83.7 to 105.2%. Finally, the trace analysis method was applied to the analysis of real forensic specimens and has achieved satisfactory results.
Subject(s)
Barbiturates/blood , Acetonitriles , Animals , Buffers , Electricity , Electrophoresis, Capillary/methods , Forensic Toxicology , Hydrogen-Ion Concentration , Injections , Methanol , Rats , Rats, Sprague-DawleyABSTRACT
A rapid method for sensitive ultraviolet detection of multiple psychotropic drugs in human plasma was developed on a low-cost and expediently fabricated hybrid microfluidic device. The device was composed of one fused-silica capillary with a sampling fracture, a poly(methyl methacrylate) board with four reservoirs, and a printed circuit board. At the optimal separation and detection conditions, the baseline separation of three kinds of psychotropic drugs including barbiturates (phenobarbital and barbital), benzodiazepines (nitrazepam, clonazepam, chlordiazepoxide, alprazolam and diazepam) and tricyclic antidepressant drugs (amitriptyline) was achieved within 200 s with separation efficiency up to 3.80 × 10(5) plates m(-1). The linear ranges for ultraviolet detection were from 2.0 to 1000.0 µg mL(-1) for chlordiazepoxide and 1.0 to 1000.0 µg mL(-1) for other seven drugs. Combining with solid-phase extraction, this novel protocol could successfully be used to screen naturally existing psychotropic drugs in a known human plasma sample. The minimum detectable concentration was down to 27 ng mL(-1) for phenobarbital spiked in plasma. This work provided a promising way to initially screen different psychotropic drugs with high resolution, rapid separation and low-cost.
Subject(s)
Electrophoresis, Microchip/instrumentation , Electrophoresis, Microchip/methods , Microfluidic Analytical Techniques/instrumentation , Psychotropic Drugs/blood , Amitriptyline/blood , Barbital/blood , Benzodiazepines/blood , Disposable Equipment , Equipment Design , Female , Humans , Limit of Detection , Male , Phenobarbital/blood , Photometry , Reproducibility of Results , Solid Phase ExtractionABSTRACT
A disposable microfluidic device was constructed by conveniently integrating one poly(methyl methacrylate) board with four reservoirs and one fractured fused-silica capillary with 50 microm i.d. and 7.5 cm total length on a printed circuit board for applying sampling and separation voltages. The disposable microfluidic device combined with a home-made ultraviolet workstation could be conveniently used for efficient screening and quantitative detection of microg mL(-1) illicit drugs. Using eight illicit drugs as models, they could be baseline-separated within 240 s with the separation efficiency up to 600,047 plates m(-1) at the designed device. The novel device and proposed protocol were successfully used to screen illicit drugs in human urine. This work presented a simple and low-cost method to fabricate the microfluidic device and provided a powerful way for sensitive and specific multi-screening of different drugs with high resolution, fast separation and low-cost.
Subject(s)
Illicit Drugs/urine , Microfluidic Analytical Techniques/instrumentation , 3,4-Methylenedioxyamphetamine/isolation & purification , Disposable Equipment , Dronabinol/isolation & purification , Ephedrine/isolation & purification , Equipment Design , Heroin/isolation & purification , Humans , Ketamine/isolation & purification , Limit of Detection , Morphine/isolation & purification , Morphine Derivatives/isolation & purification , Reproducibility of Results , Substance Abuse Detection/instrumentation , Substance Abuse Detection/methods , Ultraviolet RaysABSTRACT
Based on the records of carboxyhemoglobin in blood samples stored for recent years, the stability of carboxyhemoglobin in these samples could be affected by the containers, the storage temperatures, the volumes of air above the blood, the saturation of the initial carboxyhemoglobin and preservatives added in these blood samples, among which the storage temperatures, the volumes of air above the blood and the saturation of the initial carboxyhemoglobin are the major influence factors.
