JOURNAL OF CHEMICAL METROLOGY, vol.1, no.1, pp.1-9, 2007 (ESCI)
25-OH Vitamin D-3 and 25-OH Vitamin D-2 were determined by rapid, simple and validated LC/MS/MS method without using SPE and isotopic standard. The relative standard deviations (RSD) were found to be 3.1 and 2.8 % for 25-OH Vitamin D-3 and 25-OH Vitamin D-2, respectively. The correlation coefficient was grater than 0.99 for both analytes in the calibration range. The recoveries at 100 mu g L-1 concentration averaged to 92 % for 25-OH vitamin D-3 and 94 % for 25-OH-vitamin D-2. The uncertainty of the measurements for 25-OH vitamin D-3 and for 25-OH-vitamin D-2 was 7.77 % and 7.24 %, respectively.