Comparison of two human serum 25-hydroxyvitamin D testing methods

Objective To compare ESI-LC-MS/MS and APCI-LC-MS/MS method which are used to determine human serum 25-hydroxyvitamin D concentration. Methods The methods were developed and well-validated by establishing linearity, analytical sensitivity, recovery, precision, accuracy. 50 human serum specimens were tested by two methods separately. The results were analyzed by SPSS Statistics 17.0 software. Results The limit of qualitation of two methods was good. The analytical measurement range was all in the range of 2.1-158.0 ng/ml for 25-hydroxyvitamin D3, and 2.1-152.0 ng/ml for 25-hydroxyvitamin D2. The recovery was between 85% and 115%. The precision and maintenance frequency of ESI method was better than that of APCI. T test analysis showed there was no significant difference between the two methods. Conclusions These two methods can be substituted. However, in order to get more stable results and reduce the workload of instrument maintenance in the routine work, we recommend that ESI-LC-MS/MS method is the first choice for serum 25-hydroxyvitamin D testing in clinical laboratory.