|
Abstract 【Abstract】Objective To explore the optimization of the method for detecting 10 trace elements [copper (Cu), zinc (Zn), calcium (Ca), magnesium (Mg), iron (Fe), selenium (Se), lead (Pb), manganese (Mn), cadmium (Cd), and arsenic (As)] in capillary blood by inductively coupled plasma mass spectrometry (ICP-MS), as well as the comparability of trace elements detection results between capillary blood and venous blood. Method In this study, venous blood and capillary blood samples with volumes of 40 μl, 60 μl, 80 μl, and 100 μl were collected to investigate the stability of directly diluted blood samples. Meanwhile, a comparative analysis was conducted on the consistency of trace element contents in capillary blood and venous blood samples, with the judgment based on the allowable total error (TE) specified in the National Health Industry Standard (WS/T 403-2012). Quality control was performed in accordance with the requirements of the College of American Pathologists (CAP) quality system, and Levey-Jennings quality control charts were plotted. Statistical methods was performed by paired sample t-test. MedCalc software was applied for Passing-Bablok regression analysis to calculate the regression equations and correlation coefcients between capillary blood and venous blood samples, percentage bias was calculated; excel was used to draw Levey-Jennings charts and calculate the coefcient of variation (CV). Result The minimum blood volume required for detecting 8 trace elements (Cu, Zn, Ca, Mg, Fe, Pb, Se, and Cd) was 40 μl, while that for Mn and As was 80 μl. Directly diluted capillary blood samples could be stably stored for 72 hours under both at 4 °C and -20 °C. The detection results in venous blood of Cu, Zn, Ca, Mg, Fe, Se, Pb, and Mn in venous blood were (12.29±1.50) μmol/L, (85.71±15.19) μmol/L, (1.46±0.12) mmol/L, (1.68±0.14) mmol/L, (8.69±1.02) mmol/L, (1.43±0.20) μmol/L, (11.96±6.49) μmol/L, and (0.43±0.13) μmol/L, respectively; and those in capillary blood were (11.66±1.34) μmol/L, (84.9±13.00) μmol/L, (1.45±0.12) mmol/L, (1.65±0.13) mmol/L, (8.57±0.87) mmol/L, (1.41±0.21) μmol/L, (11.88±6.34) μmol/L, and (0.42±0.14) μmol/L, respectively. The differences in Mn, Zn, Ca, Mg, Fe, Se, and Pb levels between the two samples were not clinically significant (none exceeding 1/2 TE), while the difference in Cu levels between the two samples was statistically significant (t=7.751, P<0.001). For Zn, Ca, Mg, Fe, Se, Pb, and Mn, there were no statistically significant differences in their detection results between the two samples (t values were 1.073, 1.112, 1.723, 1.601, 0.931, 0.313, and 1.352, respectively, all P>0.05). For Mn, the proportion of Mn detection result difference between the two samples exceeded 1/2 TE was 18%, and the proportion exceeding 3/4 TE was 0%. All laboratory quality control data met the requirements of relevant national health industry standards. Conclusion The method of ICP-MS for detecting 10 trace elements in capillary blood has the advantages of requiring a small blood sample, being simple to operate, yielding stable results, and providing comparable results to venous blood analysis. It is suitable for routine clinical testing, and provides a reliable technical solution, particularly for trace elements analysis in pediatric patients.
|