Automated sample preparation using membrane microtiter extraction for bioanalytical mass spectrometry

Abstract

The development and application of membrane solid phase extraction (SPE) in 96-well microtiter plate format is described for the automated analysis of drugs in biological fluids. The small bed volume of the membrane allows elution of the analyte in a very small solvent volume, permitting direct HPLC injection and negating the need for the time consuming solvent evaporation step. A programmable liquid handling station (Quadra 96) was modified to automate all SPE steps. To avoid drying of the SPE bed and to enhance the analytical precision a novel protocol for performing the condition, load and wash steps in rapid succession was utilized. A block of 96 samples can now be extracted in 10 min., about 30 times faster than manual solvent extraction or single cartridge SPE methods. This processing speed complements the high-throughput speed of contemporary high performance liquid chromatography mass spectrometry (HPLC/MS) analysis. The quantitative analysis of a test analyte (Ziprasidone) in plasma demonstrates the utility and throughput of membrane SPE in combination with HPLC/MS. The results obtained with the current automated procedure compare favorably with those obtained using solvent and traditional solid phase extraction methods. The method has been used for the analysis of numerous drug prototypes in biological fluids to support drug discovery efforts.

Determination of plasma ziprasidone using liquid chromatography with fluorescence detection

“…Liquid chromatography with UV detection at 215 nm, preceded with a solid-phase extraction with a structurally similar analog as the internal standard, achieved a lower limit of quantitation (LLOQ) of 1 ng/ml with acceptable precision and accuracy [7]. A method for serum ziprasidone using LC-APCI-MS was reported with an emphasis on automated sample preparation [8]. This procedure resulted in a LLOQ of 0.5 ng/ml with good precision and accuracy.…”

“…4 represents a chromatogram of 0.5 ng/ml plasma extract of a ziprasidone standard. This level compares favorably with the existing LC-MS method also having the same LLOQ [8]. The upper limit of quantitation (ULOQ) was determined at 200 ng/ml (intra-assay variation: 0.83%, n = 12, Table 1).…”

Determination of ziprasidone in human plasma by liquid chromatography–electrospray tandem mass spectrometry and its application to plasma level determination in schizophrenia patients

“…There are number of reported quantitative methods using high performance liquid chromatography (HPLC)-thin layer chromatography (TLC) [17], HPLC-ultra violet [18], HPLC-mass spectrometry [19] and HPLC-fluorescence [20] for the determination of ZIP. Previously reported LC-MS-MS [16,19] methods did not provide sufficient details of the method to reproduce it in our laboratory. A recently published article describes a LC-MS-MS method with a range of 0.5-200 ng/ml when 1 ml of plasma was used for analysis [21].…”

Automated 96-well solid phase extraction and hydrophilic interaction liquid chromatography–tandem mass spectrometric method for the analysis of cetirizine (ZYRTEC®) in human plasma—with emphasis on method ruggedness

“…Method ruggedness can also be improved by employing well-established automated sample preparation strategy and eliminating or minimizing labor-intensive and timeconsuming manual operation [19][20][21][22][23]. Automated SPE using 96-well plate format has enjoyed the greatest success and is the leading industry trend for bioanalysis [19][20][21][22][23][24][25][26][27]. Here we report an HILIC-MS/MS method for analysis of cetirizine in human plasma that utilizes automated sample transfer and automated SPE based on 96-well plate format.…”