凯氏定氮蒸馏装置-高效液相色谱法同时测定蚝油等食品中丙酸钠(钙)和双乙酸钠

Simultaneous Determination of Sodium(or Calcium) Propionate and Sodium Diacetate in Oyster Sauce and Other Similar Seasonings by High Performance Liquid Chromatography Using Kjeldahl Distillation Apparatus

利用凯氏定氮蒸馏装置,建立同时检测蚝油、酱油、鱼露中丙酸钠(钙)和双乙酸钠的高效液相色谱法。蚝油等食品中的丙酸钠(钙)和双乙酸钠经过磷酸酸化后转化为相应的酸,通过凯氏定氮蒸馏装置,水蒸气蒸馏法提取,加磷酸调节蒸馏液pH值至3.0,采用高效液相色谱法进行测定。丙酸钠(钙)和双乙酸钠在0.005~1.000 mg/m L内线性良好,相关系数为0.999 9。丙酸钠(钙)(以丙酸计)、双乙酸钠的回收率分别为88.5%~108.3%和86.5%~108.7%,相对标准偏差为2.13%~6.42%和2.02%~6.37%(n=6)。方法简便快捷、稳定可靠,适用于蚝油、酱油和鱼露中丙酸钠(钙)和双乙酸钠含量的测定。

Using a Kjeldahl distillation apparatus,a method for the simultaneous determination of sodium(or calcium)propionate and sodium diacetate in oyster sauce,soy sauce and fish sauce by high performance liquid chromatography(HPLC)was established.The sodium(or calcium)propionate and sodium diacetate in samples were converted to the correspondingacids by treatment with phosphoric acid.After that,both acids were collected by steam distillation using a Kjeldahl apparatus.The pH of the distillates was then adjusted to around3.0by adding phosphoric acid.Finally,the analysis was completed withHPLC.A good linear relationship was gained in the range from0.005to1.000mg/mL with a correlation coefficient of0.9999.Recoveries of sodium(or calcium)propionate and sodium diacetate were88.5%–108.3%%and86.5%–108.7%with relativestandard deviations(RSDs)of2.13%–6.42%and2.02%–6.37%(n=6),respectively.This method is simple,rapid,easy tooperate,stable,reliable,and suitable for the determination of sodium(or calcium)propionate and sodium diacetate in oystersauce,soy sauce,fish sauce and other liquid seasonings.