[Direct determination for 22 kinds of elements in umbilical cord serum by ICP-MS]

A method for analysis of 22 kinds of elements in umbilical cord serum by inductively coupled plasma mass spectrometry( ICP-MS) was developed.

The serum samples were taken out and diluted 15 times with 2% HNO3. After centrifugation for 5 min at 5000 r/min, the supernatant was injected into ICP-MS for analysis. Ge was used as internal standard element for correcting analysis of octopole collision model( Fe, As, Se, I) and Sc, Ge, In, Bi were for standard model. ICP-MS analysis was performed on 1550 W of RF power, 15. 00 L/min of plasma gas flow rate, 0. 30 mL/min of sample injection volume and 90 ms of residence time. Octopole collision was carried out with He as reaction gas at 1. 0 L/min, 150 V of octopole RF power and5. 0 V of energy discrimination.

Internal standard curves were plotted for quantitative analysis and good linearity was obtained in their linear range( r > 0. 9993)and the limits of detection were 0. 00158-1. 21 μg/L. Control serum was analyzed withthe proposedmethod and theresult were in accordance with the standard values. The proposed method was applied to analysis of umbilical cord serum and the spiked recoveries were 86. 4%-116% with RSD of 0. 164%-18. 79%( n = 6).

ICP-MS is rapid, sensitive, accurate and simple. It can effectively determine the concentration of the elements in serum.