Abstract: The present disclosure relates generally to processes for accurate quantitation of naphthenic acids in liquid samples. The method allows efficient identification as well as quantitation of NA species based on carbon number and ring structure, but requires no chemical modification or extraction of the sample allowing a rapid throughput. Reverse phase liquid chromatographic separation of the sample minimizes (or eliminates) matrix suppression effects to allow detection of all NAs present in various samples by mass spectroscopy with superior detection thresholds that are as much as 350-fold lower than conventional methods.

Abstract: The present disclosure relates generally to systems for accurate quantitation of naphthenic acids in liquid samples. The system allows efficient identification as well as quantitation of NA species based on carbon number and ring structure, but requires no chemical modification or extraction of the sample allowing a rapid throughput. Reverse phase liquid chromatographic separation of the sample minimizes (or eliminates) matrix suppression effects to allow detection of all NAs present in various samples by mass spectroscopy with superior detection thresholds that are as much as 350-fold lower than conventional systems.

Abstract: A test fixture of the type that requires repeated manual lifting of weights in a drop-tube for performing an ASTM drop weight test, is provided with a computer automated pneumatically powered lift mechanism. The lift mechanism for the weights responds to a series of computer generated signals that are applied to a set of electropneumatic actuators for driving pistons to lift and drop the weight. Associated with the lift mechanism is a set opto-interrupter devices that generate a position signal representative of the position of the weight to be dropped as it ascends in the drop tube. In use the computer is provided with a desired drop height and essentially continuously compares the position signal with the desired drop height and releases the weight in the drop tube to impact a sample material when the position signal equals the desired drop height.