异烟肼的荷移光谱测定方法研究

Study of the Spectral Determination of Isoniazid by Charge Transfer Reaction

研究了异烟肼与7,7,8,8-四氰基对二次甲基苯醌(TCNQ)、四氯苯醌(TCBQ)和氯冉酸(chloranilicacid)的荷移反应,对反应条件进行了优化.实验指出,异烟肼与7,7,8,8-四氰基对二次甲基苯醌(TCNQ)的反应在丙酮介质中进行,其络合物分别在744nm和845nm处有较强光吸收,表观摩尔吸光系数为7.6×102L·mol-1·cm-1和1.4×103L·mol-1·cm-1,异烟肼的浓度在30—300mg·L-1范围内符合朗比定律.异烟肼与四氯苯醌和氯醌酸的反应则在乙醇介质中进行,形成络合物的最大吸收波长分别为480nm和530nm,表观摩尔吸光系数分别为1.0×103L·mol-1·cm-1和5.5×102L·mol-1·cm-1.异烟肼的浓度分别在2—200mg·mL-1、50—300mg·L-1范围内符合朗比定律.3种方法相对标准偏差分别为0.88%、1.3%和1.6%(n=8).应用拟定的方法测定异烟肼制剂的含量,结果与标准方法一致.

The charge transfer interactions of isoniazid with 7,7,8,8-tetracyanoquinodimethane(TCNQ)、tetrachlorobenzoquinone and chloranilic acid were investigated.The reaction of isoniazid with 7,7,8,8-tetracyanoquinodimethane(TCNQ) brings about good results in the acetone medium, while the reaction of isoniazid with tetrachlorobenzoquinone and chloranilic acid brings about good results in the ethanol medium. The apparent molar absorptivity of the TCNQ complex at 744nm is 7.6×10~2 L·mol^(-1)·cm^(-1), at 844 nm is 1.4×10~3 L·mol^(-1)·cm^(-1). while the apparent molar absorptivity of tetrachlorobenzoquinone complex and chloranilic acid complex are 1.0×10~3 L·mol^(-1)·cm^(-1) at 480nm and 5.5×10~2 L·mol^(-1)·cm^(-1) at 530nm respectively. The calibration curves are liner in the concentration range of 30—300mg·L^(-1) for TCNQ, 2—2 00mg·mL^(-1) for tetrachloroben zoquinone and 50—300mg·L^(-1) for chloranilic acid. The relative standard deviations of the three methods are 0.88%,1.3%and1.6%(n=8) respectively. This results of the proposed methods applied to the determination of isoniazid corresponds to standard methods.