Validation of Cadmium Determination in Polyethylene Reference Materials by Means of Solid Sampling Zeeman Atomic Absorption Spectrometry

Direct solid sampling Zeeman atomic absorption spectrometric (SS-ZAAS) method was developed for validation of cadmium determination in polyethylene. Measurements were performed by a third generation Zeeman atomic absorption spectrometer combined with an automatic solid sampler. Applied on alternative wavelength (326.1 nm) the magnetic-3-fieldmeasurement mode extended the linear range of the calibration up to 2500 ng cadmium. High analyte contents (up to 3500 ng Cd) were detectable without laborious dilution of solid samples. Limit of detection was calculated to be 12 ng cadmium according to the 3s-criterion, the maximum sample weight was about 10 mg. The use of matrix-matched solid certified reference materials (CRMs) allowed simple calibration and modifier-free determination of cadmium in polyethylene resulting in high accuracy of the method.