协同乳化制样-GFAAS直接测定口香糖中的痕量铬

Direct determination of trace chromium in gum by synergistic emulsion for sample preparation and GFAAS

目的：开发原子光/质谱分析检测中的样品前处理新技术,建立采用石墨炉原子吸收光谱法直接测定口香糖中痕量铬的新方法。方法：采用风油精做环保绿色溶剂分散溶解口香糖,单因素轮换研究风油精对样品的溶解度,选择为60 mg·m L-1壬基酚聚氧乙烯醚NP-10和NP-50为乳化剂协同乳化样品。结果：优化乳化剂配比为1∶2时乳化效果好,可快速制备稳定均匀细小的微乳液试样。新方法对铬的检出限（3σ）为0.16μg·L^-1,相应原固体样品的检出限为26.6 ng·g^-1。方法测定铬的精密度的RSD为3.8%[C样=0.6%（m/v）,n=7]。线性范围为0.5~40μg·L^-1,加标测定回收率在96%~105%间。绿箭、益达、乐天口香糖和雅客泡泡糖等食品测定铬含量分别为155.3、196.0、278.4、219.5 ng·g^-1。结论：协同乳化样品前处理技术简便、快速、均匀。新方法也可拓展应用于其他一些含胶质药品食品中铬元素的直接测定。

Objective： To develop new sample pretreatment technology for atomic spectrometry / mass spectrometry analysis and establish a new method for direct determination of trace chromium in gum by synergistic emulsion for sample preparation and GFAAS. Methods： Essential balm was used as the solvent to dissolve the gum sample. The solubility of the sample in the essential balm was studied by single factor rotation. 60 ng·g^-1nonyl pheneol polyoxyethylene ether NP- 10 and NP- 50 were used as the emulgators to emulsify samples through synergistic effect. Results： The ratio of the two emulsifiers was optimized as 1∶ 2 for the best emulsion. Uniform and stable emulsion containing tiny particle was prepared at last. The detection limit of the new method（ 3σ） was 0. 16 μg·L^- 1d the detection limit for the original solid sample was 26. 6 ng·g- 1. The precision（ RSD） was 3. 8% [Csample=0. 6%（ m / v）,n = 7]. The linear calibration range of chromium（ Cr） was 0. 5- 40 μg·L^- 1nd the recoveries for the spiked sample ranged from 96% to 105%. The determination results of Doublemint gum,Extra gum,ACUO gum and Yake bubble gum were 155. 3 ng·g- 1,196. 0 ng·g- 1,278. 4 ng·g- 1,219. 5 ng·g- 1,respectively. Conclusion： Synergistic emulsion technology for sample pretreatment is simple,fast and uniform. The new method can be also applied for the chromium determination in other gelatin- containing food and medicine samples.