Application of photoelectric titrator in the determination of total carbon in geological samples by high-temperature combustion non-aqueous titration method

This study improved a high-temperature combustion photoelectric control non-aqueous titration method for determining the total carbon content in geological samples. By integrating a high-temperature combustion tube furnace with a modified photoelectric titrator, the analytical efficiency and accuracy were significantly enhanced. The improved photoelectric titrator, through the addition of an independent absorption liquid supply channel, achieved dual-liquid path control, increasing the utilization rate of the absorption liquid by 60%. Experiments determined the optimal sample weight based on the carbon content gradient of the samples. The method's detection limit is 0.02%, with a relative standard deviation ranging from 1.21% to 3.23% and a relative error ranging from 0.21% to 3.10%, which is significantly superior to the visual titration method (detection limit 0.05%, relative standard deviation 5.31%~10.7%, relative error 2.40%~23.6%). It is particularly suitable for the determination of low-content samples. This method is simple to operate, widely applicable, and provides an efficient and reliable solution for large-scale analysis of geological samples.