电感耦合等离子体发射光谱法测定食品中钠关键影响因素探究

Research on key influencing factors of determination of sodium in food by inductively coupled plasma atomic emission spectrometry

中文关键词:  电感耦合等离子体发射光谱法  基质  钠  关键因素  内标

英文关键词:inductively coupled plasma optical emission spectrometer  substrates  sodium  key factors  internal standards

中文摘要:

      目的 探究电感耦合等离子体发射光谱法测定食品中钠关键影响因素。方法 选用不同基质的样品, 采用微波消解的前处理方法, 用电感耦合等离子体发射光谱法测定食品中的钠。通过选取589.592、588.995 nm 2条谱线、对样品稀释不同的倍数使其处于不同的线性区间、选取不同基质的样品等关键因素对检测结果进行分析研究, 并应用电感耦合等离子体质谱法对分析结果进行了验证、比对。结果 589.592 nm峰形好, 干扰小, 但电感耦合等离子体发射光谱法测定钠样品结果受溶液浓度范围、基质的影响较大, 溶液中的钠浓度小于0.5 mg/L与浓度为5.0~10.0 mg/L时, 平行实验检测结果偏差可达11.9%, 根据实验结果确定1.0~5.0 mg/L是测定钠的最佳线性范围。特殊基质的样品蒜粉、糖果不加内标时, 加标回收率分别为113.8%~117.1%和115.1%~120.0%, 而通过改进实验方法, 采用4 mg/L的锂做内标, 蒜粉、糖果的加标回收率分别为98.5%~104.8%、102.1%~104.3%。应用电感耦合等离子体质谱法进行方法验证, 样品加标回收率为97.6%~104.2%, 相对标准偏差(relative standard deviation, RSD)为0.984%~1.47%。结论 本研究指出了准确应用电感耦合等离子体发射光谱法测定食品中钠的关键点, 为准确测定食品中的钠提供了技术支持。

英文摘要:

      Objective To explore the key factors affecting the determination of sodium in food by inductively coupled plasma optical emission spectrometry (ICP-OES). Methods Samples with different matrices were selected, the pretreatment method of microwave digestion was adopted, and the sodium in food was determined by inductively coupled plasma emission spectrometry. The detectionresults were analyzed and studied by the key factors such as selecting 2 spectral lines of 589.592 nm and 588.995 nm, diluting the samples at different multiples to make them in different linear intervals, and selecting the different substrates samples. The analytical results were verified and compared by inductively coupled plasma mass spectrometry. Results The peak shape of 589.592 nm was good and the interference was small. The determination of sodium by ICP-OES was greatly affected by the concentration range of sample solution and matrix. When the concentration of sodium in the solution was less than 0.5 mg/L and the concentration was 5.0?10.0 mg/L, the deviation of parallel test results could reach 11.9%. According to the experimental results, 1.0?5.0 mg/L was the best linear range for the determination of sodium. The recoveries of garlic powder and candy without internal standard were 113.8%?117.1% and 115.1%?120.0% respectively. By improving the experimental method, the recoveries of garlic powder and candy were 98.5%?104.8% and 102.1%?104.3% respectively by using 4 mg/L lithium as internal standard. The method was validated by inductively coupled plasma mass spectrometry. The sample recovery rates were 97.6%?104.2%, and the relative standard deviations were 0.984%?1.47%. Conclusion This study points out the key points for the accurate determination of sodium in food by ICP-OES, which provides technical support for the accurate determination of sodium in food.