Interlaboratorial comparison of the determination of hardness and chloride in water had been performed by 38 and 37 laboratories, respectively. In all cases the participating laboratories used its routine methods. Homogeneity and stability testing were performed on the samples sent to the laboratories. The codified results are graphically reported and compared to assigned value, determined by the consensus of the laboratories. Satisfactory results were obtained for 71 and 73% of the laboratories, considering hardness and chloride determination, respectively.
interlaboratorial comparison; hardness; chloride
