What are the requirements for performing the method of standard addition when analyzing TCLP extracts by Method 6010?
The criteria for the method of standard addition (MSA) are outlined in Sec. 8.4 of Method 1311. In general, when the recovery of the matrix spike is less than 50%, and the analyte of concern is within 20% of the regulatory concentration, the sample must be quantified by MSA. This requirement applies to all TCLP inorganic analytes and the methods used to determine those analytes, including the current version of ICP Method 6010. Generally, most samples will not have to be analyzed by MSA when using ICP, which is less susceptible to suppression than other techniques (e.g. graphite furnace atomic absorption) that were more commonly used when the TCLP method was published. However, the laboratory may choose to apply tighter criteria than those described in the method.