Disposable pipette extraction for gas chromatographic determination of codeine, morphine, and 6‐monoacetylmorphine in vitreous humor

Abstract

The availability of a sensitive and rapid analytical method for the determination of opiates, and other substances of forensic interest, in a variety of biological specimens is of utmost importance to forensic laboratories. Solid-phase extraction is very popular in the pre-treatment of forensic samples. Nevertheless, a new approach, disposable pipette extraction (DPX), is gaining increasing interest in sample preparation. DPX has already been applied to the analysis of drugs of abuse in common biological matrices, such as urine and blood, but has not yet been evaluated on alternative biological samples, such as vitreous humor. The objective of this study was to evaluate the applicability of DPX on the analysis of opiates in vitreous humor. The currently developed method is fast, reliable, and easy to perform. The sensitivity, precision, and accuracy are satisfactory. Recoveries obtained are within the range of 72-91%, whereas the sample volume of vitreous humor required is only 100 μL.

Disposable pipette tips extraction: Fundamentals, applications and state of the art

“…The analytes were eluted with a mixture of dichloromethane, isopropanol and ammonium hydroxide (78:20:2, v/v/v). Recoveries ranged from 61 to 99% for the three analytes [8]. In a SPE method, recovery values for these analytes ranged between 98 and 103% when extracted in saline samples (similar to real vitreous humor matrix), which shows the DPX extraction is satisfactory for analysis of drugs in vitreous humor [27].…”

“…The mixing/contact time must be controlled to allow an adequate chemical interaction (by van der Waals forces in reversed-phase mode or by electrostatic interactions in ion exchanger modes), reaching the equilibrium time for analyte adsorption in sorbent particles and consequently provide an efficient extraction and good repeatability [3,7,8].…”

Multi-Target Screening of Biological Samples Using LC–MS/MS: Focus on Chromatographic Innovations

“…This feature is not an issue with recent solid-based microextractions such as disposable pipette extraction (DPX) or microextraction by packed-sorbents (MEPS), which have thus been already used in combination with LC-MS(/MS) in bioanalysis [19,33]. DPX has been already successfully applied to clinical and forensic toxicology, for example for the extraction of drugs of abuse in urine [33], opiates in vitreous humor [34] and antipsychotic drugs in urine [35]. MEPS extraction can be fully automated and on-line coupled with LC-MS, encompassing the sample processing, the extraction, and the injection steps which are performed within the same syringe [21,25,36].…”

Determination of Explosives in Water Using Disposable Pipette Extraction and High Performance Liquid Chromatography

“…Rapid equilibration, partitioning, and enhanced DISPOSABLE PIPETTE EXTRACTION FOR EXPLOSIVES 1435 contact between analytes and solid phase sorbent are also enhanced by allowing air bubbles to be drawn through the tip following sample solution. DPX has been successfully employed in extraction of analytes in various matrices, such as drugs of abuse (Samanidou et al 2013;Kovatsi et al 2011;Ellison, Brewer, and Morgan 2009) and food contaminants (Guan, Brewer, and Morgan 2009;Guan, Brewer, Garris, Craft et al 2010) in biological samples. However, there has been no report for applicability of DPX on the determination of explosives in water.…”