U.S. Centers for Disease Control and Prevention, National Center for Environmental Health, 4770 Buford Hwy, MS F-55, Atlanta, GA 30341, USA.
Anal Bioanal Chem. 2012 Jan;402(3):1123-36. doi: 10.1007/s00216-011-5550-x. Epub 2011 Nov 29.
We present here a high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantifying phytoestrogenic isoflavones (daidzein, equol, genistein, and O-desmethylangolensin) and lignans (enterodiol and enterolactone) in urine without the use of extraction or the preconcentration techniques inherent in existing methods. The development of this concept was made possible by use of atmospheric pressure photoionization (APPI); an ionization technique that we found to improve analyte sensitivity relative to electrospray ionization and atmospheric pressure chemical ionization for this particular group of compounds. The analytical performance of this method was equal to or exceeded that of comparable methods. Between-run coefficients of variation (CVs) across three quality control (QC) pool levels analyzed in duplicate over 20 days were 3.1-5.8% CV; within-run CVs were 2.3-6.0%. Accuracy, as determined by average spike recovery in QC pools, was generally within ±10% of being quantitative (100%). Relative limits of detection were 0.04-0.4 ng/mL urine, with absolute detection limits as low as 0.1 pg. This method was applied to the analysis of >2,500 urine specimens for the 2005-2006 Centers for Disease Control and Prevention's National Health and Nutrition Examination Survey (NHANES). The method was capable of quantifying these compounds in 95-100% of study samples. This work is the first ever report of using APPI for the LC-MS/MS determination of these compounds in urine. It is also the first method of its kind to do so without any need for analyte extraction or preconcentration prior to analysis.
我们在此提出一种高效液相色谱-串联质谱（LC-MS/MS）方法，用于定量尿液中的植物雌激素异黄酮（大豆苷元、雌马酚、染料木黄酮和 O-去甲安哥拉紫檀素）和木脂素（肠二醇和肠内酯），而无需使用现有方法中固有的提取或预浓缩技术。大气压光电离（APPI）的应用使得这一概念的发展成为可能；我们发现，对于这组特定的化合物，与电喷雾电离和大气压化学电离相比，这种电离技术可以提高分析物的灵敏度。该方法的分析性能与可比方法相当或优于可比方法。在 20 天内重复分析三个质量控制（QC）池水平的三个 QC 池水平，批间变异系数（CV）为 3.1-5.8%CV；批内 CV 为 2.3-6.0%。通过 QC 池中平均加标回收率确定的准确性通常在定量（100%）的±10%范围内。相对检测限为 0.04-0.4ng/ml 尿液，绝对检测限低至 0.1pg。该方法应用于 2005-2006 年疾病控制与预防中心全国健康和营养检查调查（NHANES）的>2500 个尿液标本的分析。该方法能够定量分析 95-100%的研究样本中的这些化合物。这是首次报告使用大气压光电离（APPI）在尿液中对这些化合物进行 LC-MS/MS 测定。它也是第一种不需要在分析前进行任何分析物提取或预浓缩的同类方法。
