Qualitative and relative quantitative analysis of urinary components with linear ion trap and FT ICR mass spectrometer to search for biomarkers.

The purpose of the present study was to construct a method to identify varying amounts of urinary components between two groups. We measured urine acquired from 4 healthy men and 4 healthy women with a high performance liquid chromatograph-linear ion trap and Fourier transform ion cyclotron resonance mass spectrometer (HPLC-LIT FT ICR mass spectrometer). We also rigorously compared the different amounts of compounds in men and women by multiple reaction monitoring (object and creatinine). We identified 12 compounds present in equal amounts in men and women as well as pregnanediol glucuronide, a compound found in 5.4-fold larger quantities in women than men. Urinary compounds can be identified by separating them with HPLC, and their exact mass can be measured with an FT ICR mass spectrometer, which has high resolution and high mass accuracy, and by performing multistage mass spectrometry (MS;n;) with LIT. In comparing the quantities of a compound from two groups, it is essential to correct the urine volume by measuring creatinine. The method presented here can be used to search for and identify biomarkers of disease.