火焰原子吸收光谱法测定猪肝中铜铁锌

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

用悬浮液技术及非完全消化法分别处理猪肝样品,建立了悬浮液技术和非完全消化-火焰原子吸收光谱法快速测定猪肝中铜、铁、锌的分析方法。试验表明,在悬浮液中加入适量盐酸可显著提高被测元素的吸光度,试液的粘度与空白溶液的一致,无背景吸收干扰。对非完全消化法样品处理条件、悬浮液的稳定时间及酸的影响进行了考察。相对标准偏差小于4.0%,测定结果与灰化法一致,相对误差小于±1.8%(悬浮液法),±2.7%(非完全消化法)。

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 HNO2-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）.