Determination of lead,cadmium,arsenic and total mercury in wheat flour by inductively coupled plasma mass spectrometry

Objective To develop a method for determining the contents of lead,cadmium,arsenic and total mercury in wheat flour by inductively coupled plasma mass spectrometry. Methods After wet digestion with nitric acid,the sample was determined directly by Agilent 7700s inductively coupled plasma mass spectrometry under helium collision mode,and the correction equation and mixed internal standard were used to correct matrix interference and signal drifting. Results The contents of lead,cadmium,arsenic and total mercury in wheat flour can be determined simultaneously by ICP-MS. The RSDs of the method were less than 4%,the recoveries were 95. 0% ~ 110%. The analysis results of standard material were in line with the requirements of certificate. The results of 396 wheat flour real samples were satisfactory and the concentrations of four metal elements in wheat flour in Guangdong province were within the range of safety. Conclusion The concentrations of lead,cadmium,arsenic and total mercury in wheat flour can be determined rapidly and precisely by ICP-MS. This method is simple and reliable. It can be applied to the determination of multiple elements in the same type of foods.