摘要
从测定范围、分析步骤、溴酸钾一溴化钾及滴定剂消耗量、精密度和准确度等方面对溴化容量法测定水质中挥发酚GB74911987和HJ5022009两种标准进行了比较。结果表明：HJ502—2009标准明确了挥发酚的测定范围为0．1～45．0mg／I，，增加了精密度和准确度条款，预蒸馏方式由二次蒸馏改为一次蒸馏；操作中固定溴酸钾溴化钾溶液的体积为3mL，仅一个空白试验可测试多个样品，更适合试样的批量分析。当100mL馏出液中挥发酚质量为2．35mg时，两种标准消耗的溴酸钾溴化钾溶液的量相同；当100mL馏出液中挥发酚质量小于2．35mg时，HJ502--2009标准消耗溴酸钾一溴化钾溶液和硫代硫酸钠标准溶液的量均大于GB74911987标准中溴酸钾溴化钾溶液和硫代硫酸钠标准溶液用量，当100mL馏出液中挥发酚质量大于2．35mg时，结果正好相反。建议溴酸钾溴化钾溶液的加入量由3mL变为2．5mL，100mL馏出液中挥发酚的质量小于2．35mg，以便于操作并提高试验准确度。
Two standards for determination of volatile phenolic compounds with bromine method,GB 7491--1987 and HJ 502 2009, were compared including determination range, analysis procedure, consumption of potassium bromated-potassium bromide solution and titrant, precision and accura- cy. Comparison results show that in HJ 502--2009 standard method,the determination range of volatile phenolic compounds （0.1--45.0 mg/L） is definite,which is not clear in GB 7491-1987; the content of precision and accuracy is added, and sample pre-distillation is only once, which is twice in GB 7491-1987. According to HJ 502--2009 standard method, for 100 mL distillate,the adding volume of potassi- um bromated-potassium bromide solution is fixed to 3 mL, thus one blank test is enough for multiple samples analysis, which is more suitable to batch analysis. When the content of volatile phenolic com- pounds in 100 mL distillate is 2.35 mg,the consumptions of potassium bromated-potassium bromide so- lution of these two standard method are the same; when the content of volatile phenolic compounds in 100 mL distillate is less than 2.35 mg,the consumption of potassium bromated-potassium bromide solution and sodium thiosulfate standard solution in HJ 502--2009 standard method is more than those in GB 7491--1987; however,it is contrary when the content of volatile phenolic compounds in 100 mL distillate is more than 2.35 mg. It is suggested to change the fixed volume of potassium bromated-potassium bromide solution from 3 mL to 2.5 mL,and the content of volatile phenolic compounds in 100 mL distillate should be less than 2.35 mg for easy operation and better accuracy.
出处
《石油炼制与化工》
CAS
CSCD
北大核心
2011年第12期82-85,共4页
Petroleum Processing and Petrochemicals
