Department of Clinical Biochemistry, University Hospital of South Manchester, Southmoor Road, Manchester, UK.
Ann Clin Biochem. 2010 Mar;47(Pt 2):131-6. doi: 10.1258/acb.2009.009053. Epub 2010 Feb 11.
We have developed a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for measuring salivary cortisol, which requires only 200 microL sample and no extraction.
Sample (200 microL) and 25 microL internal standard were added directly to a 96-deep-well plate. Of this, 50 microL was loaded onto a guard cartridge, the cartridge was then washed and the eluate was diverted to waste. The compounds were eluted from the guard cartridge onto the C18 analytical column. Cortisol and deuterated cortisol were monitored using transitions m/z 363.2 > 121.1 and 365.1 > 122.2, respectively.
The method had a lower limit of quantitation of 2 nmol/L. Intra-assay and inter-assay imprecision were better than 9.5%. Comparison with an established dissociation enhanced lanthanide fluorescent immunoassay (DELFIA) gave good agreement for the majority of samples; LC-MS/MS = 1.0065 x DELFIA - 3.7 (n = 130). The reference range was determined to be 5.8-45.7 nmol/L at 08:00 h and <6.4 nmol/L at 23:00 h (n = 44).
We have developed a simple, robust assay to measure salivary cortisol using on-line solid-phase extraction to reduce sample clean-up requirements.
我们开发了一种用于测量唾液皮质醇的液相色谱串联质谱（LC-MS/MS）方法，该方法仅需 200μL 样本且无需提取。
直接向 96 孔深孔板中加入 200μL 样本和 25μL 内标。其中 50μL 加载到保护柱上，然后对其进行清洗，洗脱液排入废物。化合物从保护柱洗脱到 C18 分析柱上。皮质醇和氘代皮质醇分别通过监测 m/z 363.2 > 121.1 和 365.1 > 122.2 的转换来进行监测。
该方法的定量下限为 2nmol/L。日内和日间精密度均优于 9.5%。与已建立的解离增强镧系元素荧光免疫分析（DELFIA）进行比较，大多数样本的结果具有良好的一致性；LC-MS/MS = 1.0065 x DELFIA - 3.7（n = 130）。参考范围确定为 08:00 时 5.8-45.7nmol/L，23:00 时 <6.4nmol/L（n = 44）。
我们开发了一种简单、稳健的方法，通过在线固相萃取来测量唾液皮质醇，从而减少了样本净化要求。
