IC法测定乙烯利水剂中乙烯利、亚磷酸、磷酸的含量

建立了IC法检测乙烯利水剂中乙烯利、磷酸、亚磷酸的方法。选用SH–AC–1阴离子分离柱,淋洗液选用3.6 mmol/L Na2CO3+4.5 mmol/L NaHCO3,等度淋洗,流速2.0 mL/min,进样量10μL,抑制电导检测,样品水溶解。在此条件下,线性相关系数均大于0.999;亚磷酸、磷酸和乙烯利检出限(S/N=3)分别为12.1?g/L、53.4μg/L和73.7μg/L;相对标准偏差(RSD)为0.58%、2.87%和1.26%,样品平均加标回收率在97.0%～100.1%,重现性好。该方法简便、快速、灵敏、准确,可以用于乙烯利水剂中乙烯利、磷酸和亚磷酸的同时测定。

Determination of Ethephon, Phosphorous Acid and Phosphoric Acid in Ethephon 40% AS by IC

A method for the determination of ethephon, phosphorous acid and phosphoric acid in ethephon 40% AS was established by IC. Sample was dissoluted by water; chromatographic separation was performed on a SH-AC-1 anion separator column; 3.6 mmol/L Na2CO3 ＋ 4.5 mmol/L NaHCO3 was chosen as eluant; Isoeratie elution, flow rate 2.0 mL/min, sample size 10 μL and suppressed conductivity detection were used. Under these conditions, the linear relative coefficient of ethephon, phosphorous acid and phosphoric acid attained more than 0.999; the detection limits of ethephon, phosphorous acid and phosphoric acid （S/N=3） were 12.1 μg/L, 53.4 μg/L and 73.7 μg/L, RSDs were 0.58%, 2.87% and 1.26%, respectively. Average recoveries of spiked sample were 97.0%-100.1%. The method is simple, rapid, sensitive and accurate. It is suitable for simulatenous determination of ethephon, phosphorous acid and phosphoric acid in ethephon 40% AS.