應用HPLC鑑別及定量市售冷燙燙髮劑中的THIOGLYCOLIC ACID及CYSTEINE

IDENTIFICATION AND DETERMINATION OF THIOGLYCOLIC ACID AND CYSTEINE IN COLD PERM BY HPLC

鑑於一般化學方法不易鑑別及定量同時存在於冷燙燙髮劑中的 Thiogl ycolic Acid 及 Cysteine 成分，本報告乃提供一快速而精確的高效液相層析條件以解決此問題，經多次探討利用 μ-Bondapak C18層析管、移動相為0.005M 1-octanesulfonic Acid Sodium Salt 及 0.05M potassium dihydrogen phosphate 並以磷酸調至pH2.5之水溶液，在 214 nm 測定波長下，可得到簡易而精確的分析結果。Thioglycolic acid 的相關係數0.9997，變異係數0.50%，而 Cysteine 分別為0.9999及0.57%，二者之回收率亦達98%以上。另外，為評估所擬訂之HPLC方法的實用性，乃抽購市售冷燙劑30件，採用本篇報告所述方法予以檢驗第一劑的 Thioglycolic Acid 或 Cysteine，結果除3件因無許可字號無檔索可查而不判定外，含量符合原廠規格的只有12件；不合格者有15件，其中有3件檢體標示 Cysteine 卻檢出 Thioglycolic Acid 而不含 Cysteine 成分。

In this investigation, a method was developed for the simultaneous analysis of Thioglycolic acid and cysteine, both found in permanent wave lotion by HPLC. The chromatographic condition for the analysis was C18 column (10 um, 300 x 3.9 mm I.D.), aqueous solution containing 0.005 M 1-0ctanesulfonic acid sodium salt, 0.05 KH2 PO4 and adjusted to pH 2.5 using H3 PO4 n as an eluent. The detection was set at 214 nm, separation accomplised in approximate 10 min. Its recovery was over 98%.