Flow Injection Analysis with Amperometric Detection for Morpholine Determination in Corrosion Inhibitors

In this study, an electrochemical method is proposed using flow injection analysis and amperometric detection with screen-printed carbon electrodes for morpholine determination to monitor the quality of morpholine-based commercial inhibitors and the residual concentration of inhibitors that control internal corrosion in oil industry pipelines. The amperometric method resulted in a strong linear correlation coefficient (r = 0.9941) with a linear response over a concentration range of 20-120 mg L-1, a limit of detection of 10 mg L-1 and a limit of quantification of 30 mg L-1. In addition, the method has been shown to be precise, linear and homoscedastic. The recovery for the amperometric method was 100 +/- 6%, and the recovery for the real condensate sample was 99 +/- 2%. Thus, the proposed method is promising for analysing morpholine-based commercial inhibitors in oil industry pipelines with simple and low-cost methodologies compared with ion chromatography techniques.