The paper describes the development of a fully automated instrumental procedure for testing residual corrosion inhibitors in production waters in the field. Initial investigations were conducted in the laboratory to evaluate the suitability of ultraviolet and fluorescence spectrophotometric techniques to different twes of corrosion inhibitors. Parameters for comparison included selectivity, sensitivity, speed, accuracy and precision of the methods under flowing conditions as in high performarlce liquid chromatography and static conditiorls as encountered in stand alone instruments. For the field, the number of personnel, technical experience and proximity of the district Iaboratory to the various leases were addition~al factors that were considered. The laboratory evaluations showed that fluorescence is more suitable for the field application because errors from high salinity, contamination and matrix effect are minimized in fluorescence analysis. Although the development work included most of the nitrogencontaining corrosion inhibitors (quaternary amines, imidazolines, amides, etc.), the procedure for quaternary amines is used as the example and presented in detail. Comparison of the automated fluorescence technique to the classic extraction/dye transfer technique showed the definite advantages of the former with respect to ease, speed, accuracy and precision, To the supplier, the new procedure has resulted in more timely and lower cost of analysis, more efficient utilization of field personnel, elimination of environmental and safety hazards and improved morale.
KEYWORDS: Fluorescence Spectrophotometry, Ultraviolet Absorption, High Performance Liquid Chromatography, Quaternary Amine, Residual Analysis, Corrosion Inhibitor, Produced Water, Imidazoline, Amidoamine