Capillary electrophoresis combined in-line with solid-phase extraction using magnetic particles as new adsorbents for the determination of drugs of abuse in human urine

Abstract

A simple approach is presented based on the in-line coupling between magnetic particles-based SPE and CE. Silica-coated iron oxide particles functionalized with C18 were successfully synthesized and used as a reverse-phase sorbent for in-line SPE-CE. Magnets were used to locally immobilize these sorbents inside the capillary. Four drugs of abuse were preconcentrated and determined in urine samples using the developed method with a simple pretreatment procedure based on LLE. Several parameters affecting the preconcentration were evaluated. The obtained results show that this strategy enhanced detection sensitivity in the range of 125-700-fold compared with CE without preconcentration. The developed method provides LODs (S/N = 3) for standard samples in the range of 0.5-20 ng/mL with satisfactory analytical precision, in both intraday and day-to-day experiments (RSDs <20%). The LODs (S/N = 3) reached for urine samples were in the range of 20-50 ng/mL. Relative recoveries greater than 75.9% were obtained. The established method has been applied to the analysis of drugs of abuse in urine samples from drug abusers.

Enrichment-free analysis of anionic micropollutants in the sub-ppb range in drinking water by capillary electrophoresis-high resolution mass spectrometry

“…However, CE was rarely applied for the analysis of pollutants in water analysis [12][13][14], which is mostly due to the weak concentration sensitivity. To some extent, this can be compensated by online preconcentration techniques such as inline-SPE [15] or stacking [16]. CE-MS was applied for the analysis of halogenated acetic acids (HAAs) in water samples with an acetic acid and methanol-based electrolyte [17].…”

Enantioselective determination of cathinones in urine by high pressure in‐line SPE–CE

“…To overcome this, different preconcentration strategies have been developed, and in recent years, there has been much interest in the in‐line coupling of SPE with CE (in‐line SPE–CE). In in‐line SPE–CE a microcartridge (or preconcetrator) is inserted near the inlet end of the separation capillary, so it is an integral part of the separation capillary . There are various designs used for the preconcentrator in in‐line SPE–CE, the most popular being the fritless packed bed .…”

“…In in‐line SPE–CE a microcartridge (or preconcetrator) is inserted near the inlet end of the separation capillary, so it is an integral part of the separation capillary . There are various designs used for the preconcentrator in in‐line SPE–CE, the most popular being the fritless packed bed . With this approach the preconcentrator, a small piece of capillary (2–4 mm) filled with SPE sorbent, is placed between an inlet (5–10 cm) and a separation capillary (50–100 cm) of a narrower i.d.…”

Recent advances in CE and microchip‐CE in clinical applications: 2014 to mid‐2017

“…Basic CE‐UV has been reported as a successful approach for the detection and monitoring of several drugs. Such studies have been described for the determination of cocaine, cocaethylene, heroin, morphine, 6‐monoacetylmorphine, and 4‐methylmethcathinone in urine , cocaine and its major metabolites in urine and hair samples , and erlotinib and its metabolites also in urine . The use of chiral selectors in CE has been suggested as a viable way to analyze drugs in body fluids, tissues, and in cell‐culture fluids .…”