ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

A UHPLC-PDA method for the quantitative analysis of total amino acids in infant formula with microwave-assisted acid hydrolysis

Kanate Temtrirath

Bureau of Quality and Safety of Food, Department of Medical Sciences, Ministry of Public Health, Nonthaburi, Thailand

E-mail: kanate.t@dmsc.mail.go.th

Received: 10 July 2021  Accepted: 10 January 2022

Abstract:

In this study, a simple and effective analytical method for the determination of 17 total amino acids in infant formula was established and validated. The procedure was based on microwave-assisted acid hydrolysis and conventional alkaline hydrolysis (only for tryptophan) prior to pre-column derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate and quantification using ultra-high-performance liquid chromatography (UHPLC) coupled with photodiode array (PDA) detector. For all amino acids examined, the satisfactory validation results, using certified reference material, were obtained with good linearity (R² ≥ 0.9997), high precision (HorRat < 2), and acceptable accuracy (%R 98–104). The expanded measurement uncertainty for the analytical method were not exceeding 10%. The developed method was also successfully applied to real samples. In summary, the entire outcome indicated that this UHPLC-PDA method is sufficiently appropriate for its intended purpose and can be effectively used in routine analysis for further commercial products quality monitoring program.

Keywords: Total amino acid; Infant formula; Liquid chromatography; Microwave; Hydrolysis

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02078-3

Chemical Papers 76 (5) 3065–3076 (2022)