改进分光光度法快速测定羊杂碎中亚硝酸盐含量

Determination of Nitrite in Haggis by Improved Ultraviolet Spectrophotometry

通过改进紫外分光光度法对羊杂碎中亚硝酸盐进行测定,羊杂碎试样经醋酸-水(8∶2,V/V)溶液沉淀蛋白,75℃水浴超声提取25 min后过滤。通过显色剂对氨基苯磺酸-酸萘乙二胺偶合呈紫红色,在538 nm波长处检测吸光度测定亚硝酸含量。结果表明,亚硝酸盐在0.02~0.20μg·mL^(-1)线性关系良好,相关系数为0.99825,试样在3个不同含量水平(0.20 mg·kg^(-1)、0.40 mg·kg^(-1)、1.00 mg·kg^(-1))下的加标回收率为85.8%~90.3%,RSD为0.1%~3.9%,方法检出限为0.30 mg·kg^(-1),定量限为0.80 mg·kg^(-1)。该方法简便、提取效率高、准确性好、灵敏度高,适用于羊杂碎及羊杂汤中低亚硝酸盐含量的检测。

Nitrite in haggis was determined by an improved ultraviolet spectrophotometric method,and the haggis sample was filtered after precipitation of proteins by acetic acid-water(8∶2,V/V)solution and ultrasonic extraction for 25 min at 75℃in a water bath.The content of nitrite was determined by detecting the absorbance at 538 nm through the coupling of the chromogenic agent p-aminobenzene sulfonic acid-acid naphthalene ethylenediamine to a purplishred color.The results showed that the linearity of nitrite was good in the concentration range of 0.02~0.20μg·mL^(-1)with the correlation coefficient of 0.99825,and the recoveries of the specimens spiked at three different levels(0.20 mg·kg^(-1),0.40 mg·kg^(-1),1.00 mg·kg^(-1))ranged from 85.8%to 90.3%with the RSD of 0.1%~3.9%.The limit of detection was 0.30 mg·kg^(-1)and the limit of quantification was 0.80 mg·kg^(-1).The method is simple,with high extraction efficiency,good accuracy and high sensitivity,and is suitable for the determination of nitrite in haggis and haggis soup.