硫氰酸胺和硫脲混合物中硫氰酸铵含量的测定

Determination of ammonium thiocyanate in the mixture of ammonium thiocyanate and sulfourea by titration combined with HPLC

建立了硫氰酸铵和硫脲混合物中硫氰酸胺含量的测定方法,采用滴定和高效液相色谱法组合,先通过滴定法获得硫氰酸胺和硫脲的总量,然后通过高效液相色谱法确定其中硫脲的含量,再通过差值计算获得硫氰酸胺的含量。高效液相色谱法测定硫脲含量时,采用BDS-C18色谱柱,以40%甲醇-水溶液为流动相,二极管阵列检测器检测,外标法定量分析硫脲的含量。线性方程为y=141355x+88900,相关系数为0.9915,定量限为10mg/L。50mg、100mg、200mg 3个水平的平均加标回收率为96.4%,测定值的相对标准偏差(n=5)在1.0~1.5%之间。该测定方法准确可靠,精密度高,是准确分析硫氰酸铵和硫脲混合物中硫氰酸胺含量的有效方法。

The total amount of ammonium thiocyanate and thiourea was detemined by titration and thiourea by HPLC. Then ammonium thiocyanate was calculated by differences of the two results. Thiourea was separated by HPLC on BDS-C18 column using 40% methanol water solution as mobile phase and detected by diode array detector. The minimum detection limit was 3 μg/L and the linear equation y=0.007x ＋760.72, the correlation coefficient 0. 9915, the recovery 95.9 %. The method is effective to determine the ammonium thiocyanate in the mixture with high accuracy and precision.