Improved method for rapid determination of vitamin A in small samples of breast milk by high-performance liquid chromatography

Employing a short, potassium hydroxide (KOH) saponification (25 min) and ra pid extraction with n-hexane-toluene (1:1) and a <4-min retention time, a c onvenient, rapid, accurate and precise determination of vitamin A in breast milk was developed. The recovery rate was 102.3+/-2.5% and the small relat ive standard deviation (intra-assay 1.9%, inter-assay 2.3%) resulted in hig h precision. The amount of breast milk needed is very low (1 mi) which make s the method suitable for the use in free field studies with large sample s izes. The simple extraction and separation steps allow a high throughput sc reening under routine laboratory conditions. (C) 2000 Elsevier Science BN. All rights reserved.