双波长紫外分光光度法测定红曲中洛伐他汀(Lovastatin)的含量

Determination of Lovastatin Content in Monascus by Double Wave Length UV Spectrophotometry

：对紫外分光光度计测定组曲中洛伐他汀（Ｌｏｖａｓｔａｔｉｎ）的方法进行研究。采用７５％乙醇对红曲中的Ｌｏｖｉｓｔａｔｉｎ超声提取２０ｍｉｎ。离心后用中性氧化铝柱层析吸附上清液中的色素．一定条件下Ｌｏｖａｓｔａｔｉｎ不被吸附而随着洗脱液流出．由于Ｌｏｖａｓｔａｔｉｎ在２４６ｎｍ、 ２５４ｎｍ两波长下其吸光度之差（Ａ２４６—Ａ２５４）正好能够代表一个特征吸收峰的峰高，并且经实验测定与其浓度的关系符合比尔定律．而红曲色素在此波长下△Ａ值极小，因此采用双波长紫外分光光度法能够排除样品经吸附层析分离后残存色素的干扰，完成对样品中Ｌｏｖａｓｔａｔｉｎ含量的定量测定．在本实验条件下６次重复测定加标样品的回收率为９７．５±１．３８％，变异系数为１．４％．样品中Ｌｏｖａｓｔａｔｉｎ的最低检测下限为０．６５μｍ／ｍｌ．利用本实验条件成功测定了三种红曲发酵制品中Ｌｏｖａｓｔａｔｉｎ的含量．同时测定加标回收率．结果看到实测样品的回收率都在９５％以上，标准偏差小于０．２．说明该方法具有良好的实用性．适用于中小企业对Ｌｏｖａｓｔａｔｉｎ产品的科研开发及产品质量控制．

An UV spectrophotometry method for determination of Lovastatin in Monascus was studied. Using 75% ethanol for supersonic extraction of Lovastatin from Monascus was carried out for 20 minutes. After centrifugation, the pigment of the supernatant was adsorbed by a neutral aluminum oxide colunm. Under a particular condition the Lovastatin was not adsorbed and eluted with the effluent. It was observed, that the absorbency difference between 246nm and 254nm (A246-A245) could express a characteristic absorb peak of Lovastatin, and the relationship between the absorbency variation and its concentration just obeyed the Bear Law. The above experiments indicated, using double wave length UV spectrophotometry could exclude the disturbance of the remaining pigment, and could be successfully used for Lovastatin quantity analysis. According to 6 repeated determination of the Lovastatin samples plus standard sample, their recovery rates were 97.50 ± 1.38% and the absorb variation was 1.4%. The minimum allowable detection quantity of Lovastatin was 0.65μg/ml Under the same experimental conditions as mentioned. above, the content of Lovastatin in three kinds of Monascus fermentation products were determined. For detection of recovery rate the standard Lovastatin was added at the same time. The results showed that the recovery rates of these samples were all above 95% and the standard deviation was less than 0.2. The results revealed that this method may provide a practical value for detection of Lovastatin content. It is useful in the large and medium sized enterprises for controlling and testing the quality of the products.