Rapid Determination of Copper,Iron and Zinc in Pork Liver by Flame Atomic Absorption Spectrometry

As an alternative for the time-consuming ashing method of sample decomposition,methods of incomplete digestion and suspension were applied to the treatment of pork liver samples.In the incomplete digestion method,the sample was digested with HNO3-HClO4 mixture and finally fumed with HClO4 to obtain a transparent grass-green colored solution in which Cu(Ⅱ),Zn(Ⅱ) and Fe(Ⅲ) were determined by FAAS.In the suspension method,the ground sample was mixed and shaked with agar in a definite volume to make a suspension which was stable for about 80 min.An aliquot of the suspension was used for the FAAS determination of Zn(Ⅱ) and Fe(Ⅲ) in an acidic medium of 0.96 mol·L-1 HCl.In this case,same viscosity of the sample suspension and the blank solution should be kept,in order to compensate the background absorption.Both of the proposed methods were proved to be more rapid in operation,and comparable in accuracy and precision with the ashing method,as shown by the values of RSD′s (n=6) less than 2.5% (for suspension method) and less than 4.0% (for incomplete digestion method);and as compared with the results of ashing method,the results obtained by the proposed methods showed a relative deviation of ±1.8% (suspension method) and ±2.7% (in complete digestion method).