Pre-staining paper chromatography method for quantification of γ-aminobutyric acid

The routine method of paper chromatography includes five steps: spotting, separating, drying, spraying/immersing and color development. In this paper, a pre-staining paper chromatography which only consisted of spotting, separating and color development was developed for quantitative analysis of γ-aminobutyric acid. Compared to the routine paper chromatography, the improved method is clean, rapid, inexpensive and reproducible. The effects of ninhydrin concentration, color temperature, color time and Cu2+ concentration on the color yield in the ninhydrin reaction were optimized. And then the pre-staining paper chromatography coupled with vis spectrophotometry was applied to γ-aminobutyric acid quantification. The results indicated that the limit of detection was 0.05 mg mL−1 and the linear range was from 0.5 to 20.0 mg mL−1. Furthermore, an excellent correlation coefficient was observed with an R2 = 0.998. The method is accurate (RSD < 2.64%), and has good recoveries (102.7–103.9%). The validation of the modified technique was verified by a HPLC method.