超声波浸提—加标浓度直读法快速测定大豆中的微量氟

Ultrasonic Extraction-Standard Addition-Concentration Direct-reading Method for the Rapid Determination of Trace Fluorine in Soybean

建立一种快速测定食品中微量氟的分析方法。以大豆为原料,用超声波浸提样品,用离子选择电极法进行测定,向试液中加入标准溶液后直接读取氟的浓度。结果表明:大豆中氟的含量分别为3.424、3.050μg/g,5次平行测定的相对标准偏差RSD<3.0%,与标准溶液比较,测定的相对误差为-1.25%,分析结果令人满意。本法无需作图和进行复杂计算,直观方便、实用性强、测定时间短、工作效率高,适用于现场大批量复杂样品的快速测定。

A rapid method using ion selective electrode was established for the determination of trace fluorine in soybean. The procedure was based on extraction of test portions with 1.0 mol/L HCl solution in an ultrasonic field and addition of standard fluorine solution followed by direct reading of fluorine concentration. The average fluorine contents in two samples of soybean tested were 3.42 and 3.050 μg/g respectively, with a RSD less than 3.0% （n=5）, and the relative error was -1.25% in comparison with the determination results of the standard solution. This method is simple, fast and practicable, and can meet the requirements for in situ determination of large quantities of complex matrix samples without plotting and complex calculation.