Development of a screening method for cocaine and cocaine metabolites in urine using solvent microextraction in conjunction with gas chromatography

Jager, Lowri S. de; Andrews, Anthony R. J.

doi:10.1016/s0021-9673(00)01256-5

Cited by 117 publications

(44 citation statements)

References 9 publications

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“…Similar to SPME, there are two modes of LPME sampling: direct LPME and headspace LPME (HS-LPME). The direct extraction mode has been successfully used for the determination of polycyclic aromatic hydrocarbons (PAHs) [13], organochlorine pollutants [14][15][16], nitroaromatic explosive [12,17], triazine herbicides [18], cocaine and cocaine metabolites [19] so far. Although the headspace extraction mode was first reported in 2000 [20], recently Theis et al [21] described detailed kinetic studies of headspace mode.…”

Section: Introductionmentioning

confidence: 99%

Headspace liquid-phase microextraction of trihalomethanes in drinking water and their gas chromatographic determination

Zhao

Lao

2004

Talanta

108

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In the present work, a novel method for the determination of trihalomethanes (THMs) such as chloroform, dichlorobromomethane, chlorodibromomethane and bromoform in drinking water has been described. It is based on coupling headspace liquid-phase microextraction (HS-LPME) with gas chromatography-electron capture detector (GC-ECD). A microdrop of organic solvent at the tip of a commercial microsyringe was used to extract analytes from aqueous samples. Three organic solvents-xylene, ethylene glycol and 1-octanol-were compared and 1-octanol was the most sensitive solvent for the analytes. Extraction conditions such as headspace volume, extraction time, stirring rate, content of NaCl and extraction temperature were found to have significant influence on extraction efficiency. The optimized conditions were 15 ml headspace volume in a 40 ml vial, 10 min extraction time and 800 rpm stirring rate at 20 • C with 0.3 g ml −1 NaCl. The linear range was 1-100 g l −1 for THMs. The limits of detection (LODs) ranged from 0.15 g l −1 (for dichlorobromomethane and chlorodibromomethane) to 0.4 g l −1 (for chloroform); and relative standard deviations (RSD) for most of THMs at the 10 g l −1 level were below 10%. Real samples collected from tap water and well water were successfully analyzed using the proposed method. The recovery of spiked water samples was from 101 to 112%.

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Section: Introductionmentioning

confidence: 99%

Headspace liquid-phase microextraction of trihalomethanes in drinking water and their gas chromatographic determination

Zhao

Lao

2004

Talanta

108

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“…After the equilibrium is reached, the drop with concentrated analytes is then transferred to the injection port of a gas chromatography for analysis. LPME has been successfully used for the determination of polycyclic aromatic hydrocarbons (PAHs), 11 organochlorine pollutants, [12][13][14] triazine herbicides, 15 cocaine and cocaine metabolites 16 so far. LPME was seldom used in the determination of nitrobenzenes in aqueous samples.…”

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confidence: 99%

Optimization of Nonequilibrium Liquid-Phase Microextraction for the Determination of Nitrobenzenes in Aqueous Samples by Gas Chromatography-Electron Capture Detection

Zhao

Chu

2004

ANAL. SCI.

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Nitrobenzenes are widely used in industry for making dyes, pesticides, medicines, and explosives, and also used as intermediates in many chemistry syntheses. 1 There are several probable sources for nitrobenzenes in different matrices, including oil spills, industrial and municipal effluents, and atmospheric input. Nitrobenzenes are toxic; for example, the 14-day LC50 values toward the guppy (Poecilia reticulzata) are 12.5 mg l -1 for 2,4-DNT and 18 mg l -1 for 2,6-DNT. 2 Because of the ecotoxicology of nitrobenzenes and their ubiquitous existence in the environment, they become a risk or threat to both the growth of animals and the health of humans. For these reasons, nitrobenzenes have been included on the list of priority pollutants in water environment of China. 3 Therefore, it is imperative to develop rapid and simple methods for their determination in different matrices.For the aqueous samples, liquid-liquid extraction (LLE) is probably the most widely used sample preparation method. However, the main drawback of LLE is that it is timeconsuming and labor-intensive and requires a large amount of high-purity solvents, which are expensive and toxic. 4 SPE column needs pretreatment and still requires toxic organic solvents for the elution step, although solid-phase extraction (SPE) is less time-consuming than LLE.Solid-phase microextraction (SPME) is a solvent-free sample preparation method developed by Pawliszyn and his coworkers. 5 The technique is simple, rapid and easily operated, while it eliminates the disadvantages of conventional extraction methods, such as time-consuming operation and analytes loss. But SPME also suffers from some drawbacks: it is expensive and sample carry-over is also a problem.

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“…Anyway, higher concentrations of salt curb extraction of the OPs. The presence of higher concentrations of salt change the physical properties of the extraction film and thus diminish the diffusion rates of the OPs into the organic and graphene phase 29,30 . The pH value of aqueous phase plays a fundamental role in the microextraction.…”

Section: Effect Addition Of Salt Of Ph and In Water Sample Solutionmentioning

confidence: 99%

Preconcentration and Determination of Organophosphorus Pesticides in Water Samples by Graphene Oxide Nanoparticles Reinforced Hollow Fiber Solid/liquid Phase Microextraction and Gas Chromatography-flame Ionization Detector

Mardanbeigi¹,

Ebrahimi²,

Bozorgmehr³

2015

Biosci., Biotech. Res. Asia

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Pesticides were extracted from the sample to the organic solvent immobilized in the fibre and they were desorbed in methanol prior to chromatographic analysis. Experimental parameters related to microextraction such as type of extraction time , organic solvent and agitation rate have been optimized. The extraction method has been validated for several types of real samples, and no matrix effect was observed. The technique requires minimal sample handling and solvent consumption. Using optimum conditions, low detection limits (0.03-3.91µgL "1 ) and good linearity (R2 > 0.96) were obtained. Repeatability ranged from 3.1 to 11.1%. Finally The obtained results indicated that the method can be successfully applied for microextraction and determination of pesticides in environmental samples.

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Development of a screening method for cocaine and cocaine metabolites in urine using solvent microextraction in conjunction with gas chromatography

Cited by 117 publications

References 9 publications

Headspace liquid-phase microextraction of trihalomethanes in drinking water and their gas chromatographic determination

Headspace liquid-phase microextraction of trihalomethanes in drinking water and their gas chromatographic determination

Optimization of Nonequilibrium Liquid-Phase Microextraction for the Determination of Nitrobenzenes in Aqueous Samples by Gas Chromatography-Electron Capture Detection

Preconcentration and Determination of Organophosphorus Pesticides in Water Samples by Graphene Oxide Nanoparticles Reinforced Hollow Fiber Solid/liquid Phase Microextraction and Gas Chromatography-flame Ionization Detector

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