Sample Preparation - Struggling with Analyte recory and accuracy for Primary lead impurities by ICP-OES

As the goal is to measure impurites in Pb, and the preparation involves precipitating Pb from the acid digestion solution, it's important to control the co-precipitation or scavenging of the impurity elements during the Pb precipitation. We suspect this may be occurring, and if it's possible to measure both the digestion solution and the Pb-chloride precipitated from it you might be able to determine if partitioning is occurring for the impurity elements. We're assuming that you are using ICP, and if you are using an optical emission system (OES) it might be possible to run the Pb samples directly without the Pb-chloride precipitation step. We routinely run 5% Pb solutions (50,000 ppm) as part of ICP-OES analyses for impurities, and depending upon your specific ICP this might be an option to consider. If you could provode more information regarding the instrumentation you are using and the impurities you need to measure we might be able to provide more detailed recommendations.