ஐ.எஸ்.எஸ்.என்: 2157-7064
Eduard Rogatsky, Shaynah Browne, Min Cai, Harsha Jayatillake and Daniel Stein
We report a low sample volume LC/MS method for 25OH Vitamin D analysis. The method requires only 40 μl serum, is fully automatable, fast and sensitive. The method was successfully implemented for clinical analysis of infants for vitamin D deficiency. The 6 min method has a sensitivity range from 2 to 100 ng/ml. A 3 min method was validated from 5 to 100 ng/ml range. Fast analysis, low sample volume and high sensitivity were achieved by combination of supported liquid extraction sample preparation, UHPLC chromatography and fused-core chromatographic column for separation, and highly sensitive mass spectrometry for detection. We emphasize the importance of sample preparation quality for rugged LC/MS analysis. Using SLE-based sample preparation we successfully used only 40 μl of serum while achieving a LLOQ of 2 ng/ml. We found from assayed samples, that 3-12 month old infants were not Vitamin D deficient, compared to adults. The average level of 25(OH)D3 in infants was 57.3 compared to 38.0 ng/ml for adults in a Bronx, NY patient population.