Dowload the latest Bioanalysis application notes just released by Waters

1. Providing a Universal, One-step Alternative to Liquid-Liquid Extraction in Bioanalysis
2. Improving the Cleanliness of DBS Extracts using the Ostro 96-well Sample Preparation Plate and Single Step Method
3. Eliminating Phospholipids in Drug Discovery Extractions Using a Fast, Generic Sample Clean-up Method

Providing a Universal, One-step Alternative to Liquid-Liquid Extraction in Bioanalysis

Bioanalytical methods are under constant pressure from regulatory agencies to meet requirements for matrix effects, accuracy and precision, more challenging lower limits of quantitation and incurred sample reanalysis. Liquid-liquid extraction (LLE) is a common sample preparation choice in regulated bioanalysis and can generate high analyte recoveries, clean extracts, and is perceived as low cost. In many cases, however, the choice of LLE solvent may lead to extracts saturated with phospholipids (PLs), which contribute to matrix effects and can build-up on the analytical column and the LC system. An alternative bioanalytical sample preparation technique, the Ostro sample preparation plate, and a generic LLE method were compared for the extraction of a diverse group of pharmaceutical drugs. With no method development, analyte recovery was high, >75%, for polar and nonpolar, acidic, and basic analytes, and 95% of PLs were removed relative to LLE. Ostro sample preparation plate extraction of 96 samples was achieved in half the time relative to 96-well LLE and in less than 1/10th the time if LLE was performed in individual tubes. Download application note

Improving the Cleanliness of DBS Extracts using the Ostro 96-well Sample Preparation Plate and Single Step Method

Dried blood spot (DBS) analysis has been gaining momentum in the pharmaceutical industry due to economic and ethical issues surrounding laboratory animal usage and costs associated with shipping and storing biological samples. DBS analysis can generate high analyte recoveries. However, this technique does little to eliminate endogenous interferences. Interferences, in particular residual phospholipids (PLs), can contribute to matrix effects and build-up on the analytical column and the LC system. The Ostro sample preparation plate eliminates greater than 99% of PLs and further simplifies the DBS extraction process by simultaneously extracting analytes, reducing PLs and filtering out the spot. This novel method significantly reduces sample prep time and eliminates potential analyte losses due to extract transfer, dry down, and reconstitution. Download application note

Eliminating Phospholipids in Drug Discovery Extractions Using a Fast, Generic Sample Clean-up Method

Drug discovery is a vital segment of pharmaceutical research where compounds are screened to determine therapeutic efficacy, activity, and ADME properties. Many closely related drug compounds must be rapidly analyzed and quick decisions must be made as to which drugs will continue into development and eventually clinical trials. With little time for method development, simple and universal sample prep methods such as protein precipitation (PPT) are an attractive choice. However, PPT does little to eliminate phospholipids (PLs) which contribute to matrix effects and can build-up on the analytical column and the LC system. In this publication, Ostro 96-well sample preparation plate are shown to eliminate proteins and the majority of PLs when used to screen for a group of 26 structural analogs and metabolites. Download application note