色谱 ›› 2013, Vol. 31 ›› Issue (12): 1194-1200.DOI: 10.3724/SP.J.1123.2013.09003

• 研究论文 • 上一篇    下一篇

橙汁中苯甲酸含量测定的国际比对APMP.QM-P23

国振, 符惠, 李秀琴, 张庆合   

  1. 中国计量科学研究院, 北京 100013
  • 收稿日期:2013-09-04 修回日期:2013-11-06 出版日期:2013-12-28 发布日期:2013-12-05
  • 通讯作者: 李秀琴
  • 基金资助:

    国家质量监督检验检疫总局食品安全监管专项(21-ASPAQ1302);国家质量监督检验检疫总局公益性行业科研专项(2012104010-5)

International comparison APMP.QM-P23:determination of benzoic acid in orange juice

GUO Zhen, FU Hui, LI Xiuqin, ZHANG Qinghe   

  1. National Institute of Metrology, Beijing 100013, China
  • Received:2013-09-04 Revised:2013-11-06 Online:2013-12-28 Published:2013-12-05

摘要:

建立了橙汁中苯甲酸含量的高效液相色谱-紫外检测(HPLC-UV)和液相色谱-同位素稀释质谱法(LC-IDMS)两种准确测定方法,应用于亚太计量规划组织(Asia Pacific Metrology Programme,APMP)开展的橙汁中苯甲酸含量测定的国际比对(APMP.QM-P23),取得了满意的结果,对我国在相关领域的国际计量等效互认提供了有力的支持。本研究着重考察了色谱分离条件和样品预处理条件对测定结果的影响,对两种方法测定比对样品结果的不确定度进行了详细分析研究。HPLC-UV方法的检出限(信噪比大于3)为0.75 mg/kg,在100 mg/kg添加水平下,橙汁中苯甲酸的平均回收率为99.4%;LC-IDMS方法的检出限为0.05 mg/kg,在相同浓度添加水平下,苯甲酸的平均回收率为99.6%。采用两种方法同时对样品进行测定,比对报出结果苯甲酸含量为(102.0±2.1)mg/kg(包含因子k=2)。两种方法均简单、准确、可靠,且具有较好的重现性,LC-IDMS方法由于灵敏度高更适合于橙汁中微量苯甲酸的测定。

关键词: 苯甲酸, 不确定度, 橙汁, 高效液相色谱-紫外检测, 国际比对, 液相色谱-同位素稀释质谱

Abstract:

A method was developed for the separation and determination of benzoic acid in orange juice by high performance liquid chromatography-ultraviolet detection (HPLC-UV) and liquid chromatography-isotope dilution mass spectrometry (LC-IDMS). National Institute of Metrology (NIM) of China participated the international comparison activity organized by Asia Pacific Metrology Programme (APMP) and got good results using this method. The effects of several important factors, such as the chromatographic conditions and sample preparation conditions, were investigated to acquire optimum conditions. A method of uncertainty determination was also developed which can be used in similar measurements of uncertainty. The limit of detection (LOD, S/N>3) of HPLC-UV method was 0.75 mg/kg, and the recovery of benzoic acid in orange juice at the spiked level 100 mg/kg was 99.4%. The LOD of LC-IDMS method was 0.05 mg/kg, and the recovery of benzoic acid at the same spiked level was 99.6%. The final determination result of benzoic acid in the orange juice sample by both methods was (102.0±2.1) mg/kg (coverage factor k=2). The two methods are both simple, accurate, reliable and reproducible. The LC-IDMS method is more suitable for the determination of benzoic acid at low concentrations due to its high sensitivity.

Key words: benzoic acid, high performance liquid chromatography-ultraviolet detection (HPLC-UV), international comparison, liquid chromatography-isotope dilution mass spectrometry (LC-IDMS), orange juice, uncertainty

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