建宁莲子中二氧化硫检测及污染情况分析

Detection and pollution analysis of sulphur dioxide in Jianning lotus seed

中文关键词:  建宁莲子  二氧化硫  污染  凯氏定氮蒸馏法  检测

英文关键词:Jianning lotus seed  sulfur dioxide  pollution  kaiser’s nitrogen distillation method  detection

中文摘要:

      目的 检测建宁及其周边地区出产的52批莲子中二氧化硫残留量, 以了解莲子加工过程中二氧化硫污染情况。方法 采用半自动凯氏定氮仪建立莲子中二氧化硫残留量的检测方法。莲子样品经凯氏定氮仪酸化、蒸馏, 蒸馏物用乙酸铅溶液吸收, 吸收后的溶液用盐酸酸化, 碘标准溶液滴定, 根据所消耗的碘标准溶液量计算出样品中的二氧化硫含量。结果 经统计学方法验证, 该方法与GB 5009.34-2016中的玻璃蒸馏法测定的结果无显著性差异(P>0.05); 对于0.254、0.507、1.014 g/kg水平添加回收率范围在71.9%~93.5%之间; 相对标准偏差范围在4.4%~7.8%。应用该方法对建宁及其周边地区出产的52批莲子进行二氧化硫污染检测分析, 有7批样品不同程度检出二氧化硫, 最高的83 mg/kg, 超过了50 mg/kg的标准限量, 最低的19 mg/kg。 结论 建宁莲子中二氧化硫总体污染水平不高, 但仍存在个别超标现象。

英文摘要:

      Objective To understand the sulfur dioxide pollution level during the processing of lotus seeds by detecting sulfur dioxide residues in 52 batches of lotus seeds produced in Jianning and surrounding areas. Methods Method for determination of sulphur dioxide residues in lotus seeds was established by means of a semi-automatic Kaiselding instrument. The lotus seed sample was acidified and distilled by the Kaiselding instrument. The distillation was absorbed by lead acetate solution. The absorbed solution was acidified with hydrochloric acid and the iodine standard solution titrated. The sulfur dioxide content in the sample was calculated based on the amount of iodine standard solution consumed. Results The statistical method proved that there was no significant difference between this method and the results of the glass distillation method in GB 5009.34-2016 (P>0.05). For 0.254、0.507、1.014 g/kg levels, the added recovery rate ranged from 71.9% to 93.5%. The relative standard deviation ranged from 4.4% to 7.8%. This method was used to detect sulfur dioxide pollution in 52 batches of lotus seeds produced in Jianning and its surrounding areas. Sulfur dioxide was detected in 7 batches of samples to different degrees, with the highest level 83 mg/kg, exceeding the standard limit of 50 mg/kg and the lowest level 19 mg/kg. Conclusion The overall level of sulfur dioxide pollution in Jianning lotus seeds is not high, but there are still individual excessive phenomena.