The use of a new, modified Dittmer-Lester spray reagent for phospholipid determination by the TLC image analysis technique.

A new phospholipid-specific spray reagent is described. A new phospholipid-specific spray reagent, which is a modification of the Dittmer-Lester reagent, is described in authors' studies. The difference between these two reagents is in the addition of tin (II) chloride to the proposed spray reagent. The use of the described spray reagent together with an image analysis technique allows not only for qualitative, but also for quantitative, determination of major phospholipid classes. Separation of phosphatidylserine (PS), phosphatidylethanolamine (PE) and phosphatidylcholine (PC) was conducted on an HPTLC plate with a mixture of chloroform, methanol and 25% ammonia solution in a volume ratio of 65:25:4 as mobile phase. The calibration curves were linear in the ranges of 5.0-25.0, 1.5-15.0 and 1.0-20.0 µg/spot for PC, PS and PE, respectively. The use of the new spray reagent resulted also in lower limits of detection than the standard molybdenum method for the investigated phospholipids. The proposed method was used to determine the amount of PS in the dietary supplement 'Session', and of PS, PE and PC in biological samples, with good results.