A simple, easy-to-implement HPLC method was developed and validated for simultaneous determination of two isothiazolinone preservatives, methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI), in hair care shampoo containing plant extracts. In this method, shampoo samples were first dissolved in isopropyl myristate and then MCI and MI were extracted from isopropyl myristate layer by a mixture of methanol and 0.02 M phosphate buffer solution pH 3.0 (30: 70, v/v) and analyzed on an analytical biphenyl column maintained at 25°C with a mixture of methanol and water (10: 90, v/v) in isocratic elution mode as mobile phase. Total flow rate of mobile phase was maintained at 1.0 mL per minute. The UV detection was performed at 274 nm. Injection volume was 50 μl. The method was fully validated in terms of specificity, linearity, precision, accuracy, and robustness according to requirements of AOAC International and was proved as reliable and suitable for the intended application.

中文翻译：

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同时测定含有植物提取物的洗发水中MCI和MI的HPLC方法的开发和验证。

开发了一种简单易用的HPLC方法，并已验证该方法可同时测定含有植物提取物的护发香波中的两种异噻唑啉酮防腐剂甲基氯异噻唑啉酮（MCI）和甲基异噻唑啉酮（MI）。在这种方法中，首先将洗发水样品溶解在肉豆蔻酸异丙酯中，然后通过甲醇和0.02 M磷酸盐缓冲溶液pH 3.0（30：70，v / v）的混合物从肉豆蔻酸异丙酯层中提取MCI和MI联苯柱，以甲醇和水（10：90，v / v）的混合物在等度洗脱模式下保持在25°C作为流动相。流动相的总流速保持在每分钟1.0 mL。UV检测在274nm进行。注射体积为50  μl。该方法已根据AOAC International的要求在特异性，线性，精密度，准确性和鲁棒性方面进行了充分验证，并被证明是可靠的并且适合于预期的应用。