Method for measuring harmful elements of lead, arsenic, cadmium, copper and chromium in eucalyptus oil food additive

The invention belongs to the field of chemistry and is suitable for measuring the harmful elements of lead, arsenic, cadmium, copper and chromium in a eucalyptus oil food additive. The measuring method comprises the following steps of: firstly, quantitatively splitting a sample of the eucalyptus oil food additive and placing the sample into a polytetrafluoroethylene digester of a microwave digestion instrument; secondly, digesting the sample by adding 40-50mL of nitric acid-peroxide into each 10mL of the sample of the eucalyptus oil food additive; thirdly, taking off a sample solution to cool, release pressure and discharge waste gas and adding ultrapure water to 50mL; fourthly, using 4 percent nitric acid to dilute lead, arsenic, cadmium, copper and chromium of a national standard stock solution (GBW) into standard solution mixing liquid with concentrations of 0.00microgram/L, 2.50microgram/L, 5.00microgram/L, 10.00microgram/L, 20.00microgram/L and 30.00microgram/L step by step, measuring ion abundance by using an ICP-MS (Inductively Coupled Plasma-Mass Spectroscopy) instrument, and with the concentrations as traverse coordinate and the ion abundance as longitudinal coordinate, automatically drawing an element calibration curve by a computer; and fifthly, measuring the ion abundance of the lead, the arsenic, the cadmium, the copper and the chromium in the sample solution of the third step and calculating the content of each element.