Development and Validation of Rapid Colorimetric Detection of Nitrite Concentration in Meat Products on a Polydimethylsiloxane (PDMS) Microfluidic Device

Sodium nitrite is a common practice additive in meat products for enhancing color, flavor, and microbial quality; however, several studies link its post-procession to the formation of carcinogenic N-nitrosamines. The aim of this study was to fabricate and validate a portable, rapid, and accurate microfluidic polydimethylsiloxane (PDMS) analytical device to determine the nitrite concentration in meat products. The colorimetric determination of nitrite using PDMS is based on Griess reaction. The proposed PDMS method was validated and the uncertainty evaluated according to Eurachem guidelines. Results demonstrated that PDMS device's detection and quantification limits for nitrite were 0.1 and 0.4 mg L-1, respectively. A complete correlation (R-2 = 0.99) and RSD value was 1.3-2.1% (inter-day precision) and 1.5-2.4% (intra-day precision). The PDMS method is highly robust, accurate 98.8%, and uncertainty measurement 3.5%. No significant differences between PDMS device and spectrophotometry were found during the determination of nitrite in examined processed meat products. The overall analysis of the PDMS device could be completed within 10 min. The PDMS-based device has potential applications for rapid detection and routinely screen the nitrite concentration of meat products and guarantee food safety.