Leak in evaporated milk by anodic stripping voltammetry and atomic absorption spectrophotometry: cooperative interlaboratory study.

The results of a cooperative study on the determination of lead in evaporated milk, using a double blind referee technique, are reported. This study was designed to determine the normal variability of methods currently used for lead analysis by canned food industry laboratories. Twenty-three laboratories participated in this study. Each laboratory was instructed to use atomic absorption spectrophotometry (AOAC 25.065), anodic stripping voltammetry, or carbon rod atomic absorption spectrophotometry. Overall, the results appear to be in close agreement with the spiking levels. The coefficient of variation for all laboratories was 36.0% at the 0.15 ppm lead level and 16.8% at the 0.40 ppm lead level.