Automation of Solid-Phase Microextraction in High-Throughput Format and Applications to Drug Analysis

Abstract

The automation of solid-phase microextraction (SPME) coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS) was accomplished using a 96 multiwell plate format, a SPME multifiber device, two orbital shakers, and a three-arm robotic system. Extensive optimization of the proposed setup was performed including coating selection, optimization of the fiber coating procedure, confirmation of uniform agitation in all wells, and the selection of the optimal calibration method. The system allows the use of pre-equilibrium extraction times with no deterioration in method precision due to reproducible timing of extraction and desorption steps and reproducible positioning of all fibers within the wells. The applicability of the system for the extraction of several common drugs is demonstrated. The optimized multifiber SPME-LC-MS/MS was subsequently fully validated for the high-throughput analysis of diazepam, lorazepam, nordiazepam, and oxazepam in human whole blood. The proposed method allowed the automated sample preparation of 96 samples in 100 min, which represents the highest throughput of any SPME technique to date, while achieving excellent accuracy (87-113%), precision (<or=20% RSD), and sensitivity (limit of quantitation 4 ng/mL). Automated SPME provides unique advantages over automated solid-phase extraction (SPE) including lower cost, the ability to quantitatively determine free and total drug concentrations in a single biofluid sample, and the ability to directly process whole blood samples with absolutely no sample pretreatment required.

Rapid and label-free screening of enzyme inhibitors using segmented flow electrospray ionization mass spectrometry

“…Therefore, for the segmented flow approach to be as versatile as the flow injection approach for HTS, it is necessary to develop systems that allow compatible solid-phase extraction or similar sample preparation steps that are high-throughput. One promising approach is parallel solid-phase extraction based on multiple fibers [32].…”

Application of Solid Phase Microextraction for Quantitation of Polyunsaturated Fatty Acids in Biological Fluids

“…28,31,[68][69][70][71] The presented method could be also adopted for high throughput in vitro analy--sis either in its fiber form or using thin--film ge--ometry format using automated 96--SPME device autosampler. 72 ! ASS OCIA TED C ONTENT…”

Use of a novel technique, solid phase microextraction, to measure tranexamic acid in patients undergoing cardiac surgery

“…The SPME fibre extracts molecules with weights in the range of 70-3,000 Daltons. 3,12 This leaves behind many of the contaminating salts and large-molecular-weight substances in the original serum sample. 22 In contrast, PPP retains many of these contaminants in the final extract, which can interfere with the precision and accuracy of the final measurement of the analyte.…”

“…Use of the CONCEPT 96 system enabled the extraction and desorption of 96 samples simultaneously. 11,12 This system has been described in detail elsewhere. 11,12 The optimized equilibrium time was 120 min at 1,000 rpm, and desorption time was 120 min at 1,200 rpm.…”

“…11,12 This system has been described in detail elsewhere. 11,12 The optimized equilibrium time was 120 min at 1,000 rpm, and desorption time was 120 min at 1,200 rpm. Prior to the extraction, plasma samples were diluted fourfold with phosphate-buffered saline (PBS) at pH 7.4.…”