Easy, rapid and high-throughput analytical sensing platform for theobromine quantification in chocolate and cocoa products based on batch injection analysis with amperometric detection

In this paper, for the first time, a new, easy and rapid electroanalytical sensing platform, for the reliable quantification of theobromine in food products using batch injection analysis (BIA) with amperometric detection designed for screen-printed carbon electrodes, is introduced. The experimental conditions such as supporting electrolyte, detection potential, injected volume and dispensing rate were considered for eligible analytical performance. The method has considerable advantages for routine analysis including minimal sample manipu-lation, one run analysis with low consumption of sample (100 mu L), wide linear concentration range (20 - 400 mu M), high analytical frequency (200 injections h-1), favorable limit of detection (11.4 mu M) and satisfactory precision (RSD = 5.8%, n = 50). The applicability of the developed sensing platform was verified by analysis of twelve commercially available food products (chocolate, cocoa and cocoa beans). The results were found to be statistically significant which was confirmed by the comparative titration method with potentiometric indication (according to the paired t-test at 95% of confidence interval). The introduced BIA method has great and un-questionable potential to be used as easy, rapid, low cost and high-throughput protocol for routine food analysis with minimal user training.

Automated summary

This paper introduces a new and rapid electroanalytical sensing platform for the quantification of theobromine in food products. The method utilizes batch injection analysis with amperometric detection on screen-printed carbon electrodes. The method has several advantages including minimal sample manipulation, wide linear concentration range, and high analytical frequency.