Department of Molecular Anatomy, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan.
Spectrochim Acta A Mol Biomol Spectrosc. 2011 Jan;78(1):253-7. doi: 10.1016/j.saa.2010.10.003. Epub 2010 Oct 28.
Drop-to-drop solvent microextraction (DDSME) coupled with matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) for quantitative determination of nicotinic acid in one drop of urine sample has been proposed. All parameters, such as type of organic solvent, extraction time, exposure volume solvent, pH of the sample solution that affecting the separation and preconcentration of nicotinic acid were investigated. Under the optimal conditions, the detection limit of the method was 20 ng mL(-1) and the relative standard deviations (RSD) for determination of the nicotinic acid were in the range of 8.0-12.5%. The calculated calibration curves gave linearity in the range of 80-1000 ng mL(-1). The main advantages of the proposed method are simple, fast, and small amount of sample solution is used for separation and preconcentration of nicotinic acid. This method could be also useful for the analysis of other interested analytes in small volume of biological samples, like plasma, saliva and urine, where the availability of samples are limited.
提出了一种液滴到液滴溶剂微萃取（DDSME）与基质辅助激光解吸/电离质谱（MALDI-MS）联用，用于对一滴尿样中的烟酸进行定量测定的方法。考察了影响烟酸分离和预浓缩的所有参数，如有机溶剂的类型、萃取时间、溶剂暴露体积、样品溶液的 pH 值等。在最佳条件下，该方法的检测限为 20ng mL(-1)，测定烟酸的相对标准偏差（RSD）在 8.0-12.5%范围内。计算出的校准曲线在 80-1000ng mL(-1)范围内呈线性。该方法的主要优点是简单、快速，且用于分离和预浓缩烟酸的样品溶液用量少。这种方法也可用于分析其他在小体积生物样品（如血浆、唾液和尿液）中感兴趣的分析物，在这些情况下，样品的可用性有限。
