The application of fully automated on-line solid phase extraction in bioanalysis

Microbore-based vacuum jacketed liquid chromatography for fast, efficient and sustainable high throughput bioanalysis

Extra-column band broadening can significantly reduce the performance of rapid ultra-high performance liquid chromatography-MS-based methods (UHPLC-MS). However, as we show here, UHPLC-MS/MS methods on short 2.1 mm i.d. columns can be optimized to reduce band broadening by simple procedures such as dispensing with the solvent divert valves placed between the column and the MS source. Vacuum jacketed columns have previously been shown to provide superior performance to conventional UHPLC-MS/MS by reducing on and post column band broadening. Here we have compared the optimized "direct" UHPLC approach for the high throughput (HT) bioanalysis of drugs and metabolites in biofluids such as urine and blood plasma with vacuum jacketed chromatography (VJC), using columns of the same geometry and packed with the same stationary phases. This study demonstrates that the performance of VJC was still superior to the direct UHPLC-MS/MS methods for rapid "generic" bioanalysis using gradient times of 0.25 to 5 min. Further investigations using microbore VJC-MS/MS, with 1 mm i.d. columns, for bioanalysis of the same biofluid samples showed that this format offers great promise for HT "discovery" drug and metabolite analysis/profiling. In addition the reduction of solvent use, by up to 90 % for methods when using microbore columns, can significantly contribute to improved sustainability and reducing costs per analysis.

A Review on Recent Applications of High-Performance Liquid Chromatography in Metal Determination and Speciation Analysis

High-performance liquid chromatography (HPLC) has several advantages over the conventional methods due to their operational simplicity. It is a vital tool to determine metal ions having same mass but different electronic configuration, to separate complex mixtures and to resolve ions that may be indistinguishable by mass spectrometry alone. Metal ions play vital role in many biological processes and involved in setting up of many diseases. Therefore, the development of simple methods for the detection and quantification of metals in real samples might serve as diagnostic tools for various diseases. This review article focuses on the recent main feature of this technique, i.e. speciation of metal ions and their applications to series of problem of metal ion chemistry in different environmental matrixes. Speciation of metals is of increasing interest and has a great importance because of bioavailability, environmental mobility, toxicity and potential risk of metals. With the capability of partitioning the complex species of different metal ions, HPLC is an efficient technique for this task. This review summarizes recent advances in the development of HPLC to the fundamental understanding of metal ion chemistry in the environment and discusses all the issues that still need a lot of consideration. It has been classified into different sections depending on the role of HPLC in separation used and metal speciation; furthermore, the underlying sample preconcentration techniques and detection systems involved for the determination of metal ions and their applications were discussed.

A simple and automated online SPE-LC-MS/MS method for simultaneous determination of olanzapine, fluoxetine and norfluoxetine in human plasma and its application in therapeutic drug monitoring

An integration of sample pretreatment automation using online SPE technique could provide an easy to use, efficient, sensitive and high quality methods for TDM.

Simultaneous determination of a broad range of cardiovascular drugs in plasma with a simple and efficient extraction/clean up procedure and chromatography-mass spectrometry analysis

A simple, easy to use and efficient method was described for simultaneous determination of ten cardiovascular drugs with a broad range of physicochemical properties in rat plasma via online SPE and HPLC-MS/MS.

Optimization of on-line solid phase extraction and HPLC conditions using response surface methodology for determination of WM-5 in mouse plasma and its application to pharmacokinetic study

Response surface methodology (RSM) was utilized for rapid and systematic optimization of on-line solid-phase extraction (SPE) parameters to maximize the response and separation of WM-5. The optimization was performed with Box-Behnken designs. Four major parameters were investigated for their contributions to the response and separation of WM-5, with a total of 29 experiments being performed for each instrument, respectively. Quantitative determination of WM-5 in mouse plasma was performed to evaluate the statistical significance of the parameters on chromatographic response. A fully automated on-line SPE and high-performance liquid chromatography (HPLC) with diode array detection (DAD) method was developed for the determination of WM-5 in mouse plasma. Calibration curve with good linearity (r=0.9989) was obtained in the range of 20-4000 ng/mL in mouse plasma. The limit of detection (LOD) and lower limit of quantification (LLOQ) of the assay were 6 ng/mL and 20 ng/mL, respectively. The overall intra-day and the inter-day variations were less than 1.90%. The recovery of the method was in the range of 93.74-96.33% with RSD less than 3.06%. The optimized method demonstrated good performance in terms of specificity, LLOQ, linearity, recovery, precision and accuracy, and was successfully applied to quantify WM-5 in mouse plasma to support the pharmacokinetic study.

Automated micropipette tip-based SPE in quantitative bioanalysis

Background: Automated methodologies using silica-based, monolithic, micropipette tip-based SPE have been developed for the analysis of small molecules in support of both preclinical and first-in-human development studies using LC–MS/MS. The use of micropipette tip-based SPE with the Tomtec Quadra 96® and the evaluation of prototype micropipette tips for use with the Hamilton Microlab® Star robot is outlined. Results: Mixed-mode cation exchange and C18 SPE methods have been developed using human and rat plasma for the extraction of lipophilic and polar analytes. These methods are advantageous as they use low plasma sample, washing and elution volumes and result in a method extraction cycle time of approximately 6.2 min for 96 samples. Conclusion: This significantly reduced extraction time, compared with 96-well plate format SPE, indicates that the sample preparation stage is no longer the rate-limiting stage in performing a selective extraction procedure. Robust and sensitive methods have been developed that have proven to be more cost effective than traditional 96-well plate format SPE methods.