[Test method for lead in metal utensils for food contact use]

We compared test methods for measurement of lead in metal utensils using flame-atomic absorption spectroscopy (AAS), graphite furnace-AAS (GFAA), inductively coupled plasma atomic emission spectrometry (ICP) and X-ray fluorescence analysis (XRF). The procedure for preparation of the test solution was improved. A 100 mg of sample was dissolved in 2.5 mL of HCl and HNO(3) (3 : 1) mixture (in the case of titanium sample, dissolved in HCl). Stock solution was prepared by diluting to 50 mL with water. The test solution was prepared by diluting with 0.1 mol/L HNO(3). The recoveries of lead added to various kinds of metal reagent at the level of 0.1% were 90-118%. When standard materials which contained lead at the level of 0.0098-0.11% were measured, the measured values were in close agreement with the standard values. These procedures are applicable to aluminum, iron, stainless steel, copper, tin and titanium products. The AAS method, GFAA method and ICP method were suitable as the lead test methods. Moreover, the XRF method was useful as a screening method or a simple determination method. The ICP method was used to determine the lead contents in 22 kinds of commercial metal utensils, and 0.011-0.040% of lead were detected in 6 samples.