Application of Soluble Membrane Filter in Simultaneous Determination of Trace Levels of Cadmium, Copper, Lead and Zinc in Food Additives by Inductively Coupled Plasma Atomic Emission Spectrometry
A method for simultaneous determination of trace levels of Cd(II), Cu(II), Pb(II) and Zn(II) in food additives by inductively coupled plasma atomic emission spectrometry ( ICP–AES ) after soluble membrane filter pre-concentration was developed. Based on collection of the chelates of metal ions(II) with 2-(5-bromo-2-pyridylazo)-5- diethylaminophenol ( 5-Br-PADAP ) on soluble membrane filter, the analyte ions were pre-concentrated and separated from sample matrix solutions. Multi-channel membrane filter device and soluble mixed cellulose ester membrane were selected. Analytical parameters such as pH, amount of 5-Br-PADAP, sample volume, etc. were optimized. Under the matrix of Na+, K+ and Mg2+, the limits of detection were 0.02 – 0.03, 0.14 – 0.23, 0.31 – 0.53, 0.10 – 0.15 μg L-1 for Cd(II), Cu(II), Pb(II) and Zn(II) respectively. The developed method was successfully applied to sodium benzoate, potassium sorbate and basic magnesium carbonate with spiked recoveries of 94% – 115%. Some sample analysis results were checked by inductively coupled plasma mass spectrometry ( ICP–MS ) directly.
Zhong Cao, Yinghe He, Lixian Sun and Xueqiang Cao
Z. K. Zhu et al., "Application of Soluble Membrane Filter in Simultaneous Determination of Trace Levels of Cadmium, Copper, Lead and Zinc in Food Additives by Inductively Coupled Plasma Atomic Emission Spectrometry", Advanced Materials Research, Vols. 236-238, pp. 2236-2241, 2011