Nonaqueous Capillary Electrophoresis–Sample Stacking Determination of Acrylamide Residue in Super Absorbent Polymers of Diapers

Abstract

Acrylamide is a mutagenic and likely carcinogenic molecule. Incomplete polymerization of commercial acrylamide-based polymers leaves residual acrylamide molecules that pose a threat to human health and the environment. Acrylamide, being a polar molecule, is readily soluble in water but cannot be easily ionized in an aqueous environment. Therefore, the conventional capillary zone electrophoresis method is challenging to apply to acrylamide molecules. In this study, a capillary electrophoresis method that alters the acid–base properties of acrylamide under nonaqueous conditions, thereby imparting electrophoretic mobility to the molecule and increasing sensitivity through sample stacking, was used to detect acrylamide residues in absorbent polymers used in baby diapers. The method exhibited excellent analytical performance, with a linear range of 20–500 µg/L (R² = 0.9999), limits of detection and quantification of 5.3 and 17.7 µg/L, respectively, and satisfactory precision and recovery values. The applicability of the proposed approach was demonstrated by analyzing five commercial baby diaper samples. Acrylamide was detected in all samples at concentrations ranging from 0.483 to 1.36 µg/g, indicating the presence of residual monomer associated with polyacrylamide-based superabsorbent polymers. These findings highlight the capability of combining nonaqueous capillary electrophoresis (NACE) with online preconcentration techniques for the sensitive determination of acrylamide in complex polymer-based matrices and emphasize the importance of monitoring such residues in hygiene products intended for infant use.