Hensel R R, King R C, Owens K G
Rhone-Poulenc Rorer Pharmaceutical, Inc., Collegeville, PA 19426, USA.
Rapid Commun Mass Spectrom. 1997;11(16):1785-93. doi: 10.1002/(SICI)1097-0231(19971030)11:16<1785::AID-RCM78>3.0.CO;2-Q.
The goal of this work is the development of a rapid and objective matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) method for the quantitation of peptides and proteins in human plasma suitable for use in the Good Laboratory Practices (GLP) environment, where the analytical method, validation and pharmacokinetic parameters derived from concentration data will be scrutinized by global regulatory agencies. Electrospray deposition has traditionally been used to prepare thin, uniform samples for a number of techniques, including Cf-252 plasma desorption and secondary ion mass spectrometry. Here the electrospray process of sample application is used to reduce the segregation of analyte from matrix during the sample drying step. The small droplets formed during the electrospray process are found to significantly improve the homogeneity of the sample surface prepared. Experiments comparing the traditional air dried and electrosprayed methods of sample preparation show that the increase in sample homogeneity from electrosprayed samples decreases both the within-sample spot and between-sample spot variability, resulting in a decrease in percent coefficient of variation (%CV) for the recorded MALDI mass spectra. The increase in sample homogeneity permits a more objective use of MALDI-TOFMS as a quantitative analytical method and has led to the development of an assay for the determination of desamino-[8-D-arginine] vasopressin (DDAVP) using arginine vasopressin (AVP) as internal standard in human plasma. The range of quantitation observed (2.0-10 micrograms/mL) is of limited value for bioanalytical application; however, the analysis of neat standards shows lower quantitation limits are easily achieved.
本研究的目标是开发一种快速、客观的基质辅助激光解吸/电离飞行时间质谱（MALDI-TOFMS）方法，用于定量测定人血浆中的肽和蛋白质，该方法适用于良好实验室规范（GLP）环境，在这种环境下，分析方法、验证以及从浓度数据得出的药代动力学参数将受到全球监管机构的严格审查。传统上，电喷雾沉积已被用于为多种技术制备薄而均匀的样品，包括Cf-252等离子体解吸和二次离子质谱。在此，样品施加的电喷雾过程用于减少样品干燥步骤中分析物与基质的分离。发现电喷雾过程中形成的小液滴显著提高了所制备样品表面的均匀性。比较传统空气干燥和电喷雾样品制备方法的实验表明，电喷雾样品的样品均匀性提高降低了样品内斑点和样品间斑点的变异性，导致记录的MALDI质谱的变异系数百分比（%CV）降低。样品均匀性的提高使得MALDI-TOFMS作为定量分析方法的使用更加客观，并导致开发了一种以精氨酸加压素（AVP）作为内标物测定人血浆中去氨基-[8-D-精氨酸]加压素（DDAVP）的分析方法。观察到的定量范围（2.0-10微克/毫升）在生物分析应用中的价值有限；然而，对纯标准品的分析表明，很容易实现更低的定量限。
