双波长褪色分光光度法测定盐酸美西律

Determination of Mexiletine Hydrochloride by Dual Wavelength Fading Spectrophotometry

建立了一种快速、灵敏测定药物中盐酸美西律的双波长分光光度法。在弱碱性溶液中,虎红与盐酸美西律反应生成离子缔合物,使溶液发生褪色现象,光谱曲线上呈现2个较强的负吸收峰,它们分别位于472和560 nm,在此2个波长处,盐酸美西律的线性范围为0.04~2.6 mg/L,表观摩尔吸光系数(κ)分别为5.87×10^(4)(472 nm)和3.59×10^(4) L/(mol·cm)(560 nm),检出限为0.033(472 nm)和0.035 mg/L(560 nm)。用双波长法测定时,其表观摩尔吸光系数(κ)达9.46×10^(4) L/(mol·cm),检出限为0.017 mg/L。双波长法用于盐酸美西律药片测定,加标回收率为97.7%~103%,相对标准偏差(RSD)为2.2%~2.6%。

A new dual-wavelength fading spectrophotometry was established for the rapid and sensitive determination of mexiletine hydrochloride in drugs. In a weak alkaline solution, rose bengal reacted with mexiletine hydrochloride to form an ionic association complex, which made the solution fade. Two strong negative absorption peaks located at 472 and 560 nm appeared on the spectrum with a linear range of mexiletine hydrochloride between 0.04 and 2.6 mg/L and the apparent molar absorptivity(κ) of 5.87×10^(4) L/(mol·cm)(472 nm) and 3.59×10^(4) L/(mol·cm)(560 nm). Detection limits were 0.033(472 nm) and 0.035 mg/L(560 nm), respectively. When the dual-wavelength method was employed, the apparent molar absorption coefficient(κ) was up to 9.46 10^(4) L/(mol·cm) and the detection limit was 0.017 mg/L. When thus method was applied to the drugs, the standard addition recovery was 97.7%~103% and the relative standard deviation(RSD) was 2.2%~2.6%.