Pre-column derivatization HPLC method for rapid and sensitive determination of free and total formaldehyde in hair straightening products

Abstract

This paper describes development and validation of rapid and sensitive pre-column derivatization HPLC method to determine free and total formaldehyde content in five hair straightening products purchased from the local market. None of these products was labeled to contain formaldehyde and all of them were labeled with specific formaldehyde releasers. The formaldehyde derivative was separated using a µBondapak™ C18 column with mobile phase consisted of acetonitrile: water (70:30, v/v) and detected at 350 nm. The method was linear over the concentration range of 8–80 ng mL−1 (r = 09997) with detection limit of 0.8 ng mL−1. The formaldehyde derivative was stable for 30 days at room temperature. The results showed that all the samples were formaldehyde positive. The concentrations of free and total formaldehyde were 0.015–3.336 g% and 1.462–3.877 g%, respectively. The method showed high precision as the values of relative standard deviations (RSD) did not exceed 2.20%. Keywords: Formaldehyde, Formaldehyde-releaser, Pre-column derivatization, HPLC, Hair straightening products