摘要
基于稀磷酸介质中,氯化十六烷基三甲基铵对亚硝酸根催化溴酸钾氧化甲基红褪色反应的增敏作用,建立了测定痕量亚硝酸根的增敏催化动力学光度法。加入氯化十六烷基三甲基铵后,体系的灵敏度增大了4.3倍。研究了催化反应的动力学条件,测定了反应的表观速率常数(k=1.02×10-3/s)和表观活化能(Ea=42.76kJ/mol)。测定亚硝酸根的线性范围为5.0～300μg/L,检出限为0.59μg/L,方法的相对标准偏差优于2%,标准加入回收率为99%～101%。用于食品样品中亚硝酸根的测定,结果满意。
A catalytic kinetic spectrophtometric method was developed to determine nitrite with cetyl trimethy- lammonium chloride （CTMAC） sensitizer. In the presence of nitrite, methyl red can be oxidized with potassium bromate in the solution of dilute H3PO4. When CTMAC was used as a sensitizer, the sensitivity increased by 4.3 times. The kinetic condition was studied and the apparent rate constant and apparent activation energy were determined（k=1.02×10^-3/s, Ea=42.76kJ/mol）. The linear range is 5.0～300μg/L with detection limit of 0.591μg/ L. The RSD of the method is less than 2.0%, the recovery of nitrate was in the range of 99%～101%. The method has been applied to the determination of nitrite and nitrate in food samples with satisfactory results.
出处
《食品科技》
CAS
北大核心
2007年第7期222-224,共3页
Food Science and Technology
基金
徐州师范大学自然科学基金项目
