Development and validation of a new method for determination of methylparaben in Iran market infant formulae by HPLC

Background Parabens are esters of p-hydroxybenzoic acid and are widely used as preservatives in cosmetics, pharmaceuticals and foodstuffs. The presences of parabens in infant formulas raise concerns due to their potential to disrupt endocrine function in infants and cause reproductive toxicities. Methods In this study a new method was developed for extraction and determination of methylparaben in infant formulas using HPLC method and UV detector. Methanol and trichloroacetic acid were used for extraction and isocratic mobile phase comprising equal proportions of glacial acetic acid in water (50:850 v/v) and methanol was used for separation of methylparaben. Results Recovery of the extraction procedure was good and interferences between methylparaben and other ingredients peaks in HPLC chromatograms decreased. The average recoveries for methylparaben were about 88-108 %. The limit of detection and limit of quantitation for methylparaben were 0.2 and 0.5 mu g/mL, respectively. Results of the method showed good reproducibility (relative standard deviation (RSD) 0.29-1.94 % for within day analysis and 0.84-2.18 % for between day analysis). Results were linear in range of 0.5-20 mu g/mL methylparaben. The results of twenty real infant formula samples showed methylparaben was found only in one sample in concentration 0.3 mu g/mL. Conclusions The new extraction and measurement method was a short-time method and could be applicable for large numbers of samples. This method was fast, sensitive and accurate and was capable of being used in legal laboratory references for determination of methylparaben content.