Study on a Matrix Modifier for the Determination of Trace Cobalt and Zinc in Dried Persimmon by Atomic Absorption Spectrometry

Objectives To determine the content of Zn and Co in dried persimmon from Shanxi by using a matrix modifier in graphite furnace atomic absorption spectrometry (GFAAS).

Methods A closed microwave digestion system was used to reduce the loss of elements in sample during digestion. 5 to 10 μL of PdCl₂ +2% ascorbic acid solution (measured value 1 600 mg/L by weight) was used as a matrix modifier, and the determination of Co and Zn was corrected by using deuterium lamp as background.

Results In the determination of Co and Zn, the recovery rates of standard addition were 96.2%~102.4% and 89.2%~107.8% respectively, the relative standard deviations of the method were 6.1% and 8.2%, respectively, and the detection limits were 0.50 ng/mL and 0.1 ng/mL respectively.

Conclusions The method was convenient, rapid, sensitive, stable and low in interference; the method was suitable for the analysis and determination of Zn and Co in dried persimmon.