肾上腺素的示波极谱行为及测定

Oscillopolarographic Behavior and Determination of Epinephrine Hydrochloride

以0．1mol·L^-1磷酸二氢钾-磷酸氢二钾缓冲溶液作底液，肾上腺素在示波计时电位图阴极支-0．45V（vs．SCE）处产生1个灵敏的切口，该切口深度随肾上腺素浓度增大而加深，基于此建立了测定针剂中肾上腺素的示波计时电位方法。试验结果表明：测定肾上腺素线性范围为2．0×10^-5～2．0×10^-4mol·L^-1，线性回归方程为h=0．641＋2．84×10^3c（式中h为切口深度，单位V，c为肾上腺素浓度，单位mol·L^-1），相关系数为0．9961，检出限为6×10^-6mol·L^-1；应用此方法测定了针剂试样中肾上腺素的含量，所得结果与标示值相符，其相对标准偏差（n=8）为2．5％，加入标准溶液作回收试验，测得回收率结果在98．0%～101．6％之间。

In a base solution of 0. 1 mol · L^-1 KH2PO4-K2HPO4 buffer medium, a sensitive incision given by epinephrine was observed at -0. 45 V （vs. SCE） of cathodic branch on the curve plotting dE/dr against E, and the depth of incision was found to increase with the increase of concencentration of epinephrine. As shown by results of further study, linear relationship between depth of incision and concentration of epinephrine was obtained in the range from 2. 0 × 10^-5 -2. 0 × 10^-4 mol · L^-1, in respect to the linear regression equation of h = 0. 641 ＋2. 84 × 10^3c （r=0. 996 1）. Detection limit was found to be 6 × 10^-6 mol·L^-1. Based on these facts, a direct method for determination of epinephrine in injections by ocillographic chronopotentiometry was proposed. In analyzing samples of epinephrine injections, results obtained were in conformity with the labelled value, with the value of RSD （n=8） 2. 5%. Test for recovery was made, and the results found were in the range from 98. 0% to 101.6%.