Recent advances in electrochemical monitoring for the detection of the chemical oilfield tracer carmine

Accurate and efficient detection of chemical oilfield tracers is essential for enhanced oilfield geological analyses. We report the development of an electrochemical sensor for detecting carmine (CM) using coal tar pitch secondary residue (CTPSI) as a carbon precursor. Porous carbon materials derived from CTPSI (CTPSI-PC) were synthesized through high-temperature carbonization and strong-alkali activation. The CTPSI-PC material had high specific surface area, excellent conductivity, and a dense porous structure. Under optimized conditions, the constructed sensor demonstrated good electrochemical performance for CM detection, with a wide linear range of 10-200 μM, high sensitivity of 5.7324 A L cm² mol^-1, and a low limit of detection of 0.017 μM (S/N = 3). In real oilfield water samples, the recovery rate was 99.4% and 103.2%, showing excellent reproducibility, stability, and selectivity against common interfering ions. These findings highlight the potential of CTPSI-PC-based electrochemical sensors as efficient and reliable tools for quantitative detection of oilfield tracers, and lays a foundation for practical applications in oilfield monitoring.