Gabriëls Margriet, Camu Frederik, Plaizie-Vercammen Jacqueline
VUB Pharmaceutical Technology and Physical Pharmacy, Brussels, Belgium.
J AOAC Int. 2002 Nov-Dec;85(6):1273-87.
Degradation products of egg phosphatidylcholine (EPC) and cholesterol were analyzed with different normal- and reversed-phase thin-layer chromatography (TLC) systems. The best separation, in terms of the highest number of degradation products from both analytes, was obtained with a reversed-phase system, using butanol-methanol-water-96-98% (v/v) acetic acid (40 + 40 + 20 + 4, v/v/v/v) as the mobile phase after overnight saturation at 25 degrees C. A special development technique was used. After a first development, the plate was dried and a second development was performed in the same direction. This method enabled us to separate lysophosphatidylcholine, several free fatty acids and hydroperoxides, and several undefined degradation products of EPC and cholesterol. All products were visualized after the plate was dipped in a 1% (v/v) solution of 4-methoxybenzaldehyde in 98% sulfuric acid-96-98% (v/v) acetic acid-ethanol-water (2 + 10 + 60 + 30), presenting a blue color or a white spot against a colored background. After activation at 110 degrees C, a stable color for both analytes was reached after 12 min. Precision of <5% was obtained at 2 levels of analysis. Good linearity was obtained in the range of 5-30 microg for EPC (r = 0.991) and 5-40 microg for cholesterol (r = 0.991). These results show that TLC can be an inexpensive and easy alternative for the analysis of EPC and cholesterol.
采用不同的正相和反相薄层色谱（TLC）系统对鸡蛋磷脂酰胆碱（EPC）和胆固醇的降解产物进行了分析。就两种分析物的降解产物数量最多而言，使用反相系统可实现最佳分离，该系统以丁醇 - 甲醇 - 水 - 96 - 98%（v/v）乙酸（40 + 40 + 20 + 4，v/v/v/v）为流动相，在25℃过夜饱和后使用。采用了一种特殊的展开技术。第一次展开后，将板干燥，然后沿相同方向进行第二次展开。该方法使我们能够分离溶血磷脂酰胆碱、几种游离脂肪酸和氢过氧化物，以及EPC和胆固醇的几种未定义的降解产物。将板浸入4 - 甲氧基苯甲醛在98%硫酸 - 96 - 98%（v/v）乙酸 - 乙醇 - 水（2 + 10 + 60 + 30）中的1%（v/v）溶液后，所有产物均可见，在有色背景下呈现蓝色或白色斑点。在110℃活化后，12分钟后两种分析物均达到稳定颜色。在两个分析水平上获得的精密度<5%。EPC在5 - 30μg范围内（r = 0.991）和胆固醇在5 - 40μg范围内（r = 0.991）均获得良好的线性关系。这些结果表明，TLC可成为分析EPC和胆固醇的一种廉价且简便的替代方法。
