Dispersive liquid-liquid microextraction based on solidification of floating organic drop and high-performance liquid chromatography to the analysis of cocaine's major adulterants in human urine.

Dispersive liquid-liquid microextraction based on solidification of floating organic drop and high-performance liquid chromatography to the analysis of cocaine's major adulterants in human urine. Toxicology. 2016 Apr 30; Authors: Sena LC, Matos HR, Dórea HS, Pimentel MF, de Santana DC, de Santana FJ Abstract A simple method has been proposed for the determination of cocaine's major adulterants (caffeine, levamisole, lidocaine, phenacetin, diltiazem, and hydroxyzine) in human urine by dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) in combination with high-performance liquid chromatography - photodiode array detector (HPLC-PDA). The reversed-phase chromatographic separation was obtained with a column C18 extended (250×4.6mm; 5μm; 80Å) in gradient elution mode using acetonitrile-trifluoroacetic acid 0.026% (v,v) (pH=2.5) at 1mLmin(-1) as mobile phase, at 25°C, and detection at 235nm. The analysis time was 25min. This condition had the best resolution factors (>1.15), retention factors (>0.68), number of plates (>2094.9), and separation factors (>1.05) for all targets, indicating a good separation. The kind of extraction and dispersive solvent were investigated for unifactorial design. The buffer pH, the volume of extraction and disperser solvent, and the amount of salt were optimized for full factorial design. Under optimum conditions, human urine samples were alkal...
Source: Toxicology - Category: Toxicology Authors: Tags: Toxicology Source Type: research