甲醛标准样品的不同处理方式对其测定值的影响

Effect of Different Processing Methods of Formaldehyde Standard Samples on Their Determined Values

按照甲醛标准样品标准证书的方法配制标准甲醛溶液作为质控样,利用酚试剂分光光度法测定甲醛含量值,发现测定结果小于标准值。因而根据酚试剂分光光度法的原理,配制标准甲醛溶液时添加不同摩尔比的酚试剂原液,再加纯水定容。研究发现当加入酚试剂原液:标准样品摩尔比为5:1以上时,测定的甲醛值符合标准证书上的标示值。另发现当比例添加10:1时,标准溶液放置3 d内测定值均在标准值范围内。

The standard formaldehyde solution was prepared as quality control sample according to the method of standard certificate of formaldehyde standard sample.The results were found to be less than the standard values while the content of formaldehyde was determined by phenol reagent spectrophotometry.According to the principle of phenolic reagent spectrophotometry,different molar ratios of phenolic reagent solution were added to prepare standard formaldehyde solution,and purified water was added to constant volume.It was found that when the molar ratio of phenol reagent solution to standard sample was more than 5:1,the measured formaldehyde value met the label value on the standard certificate.Besides,it was found that when the ratio was 10:1,the measured values of the standard solution were within the range of the standard values within 3 days.