The report gives results of an investigation of the use of stable isotopically labeled compounds as internal standards for quantitative isotope dilution GC/MS determinations. The availability of labeled compounds and the costs associated with using them for routine analyses were evaluated using the volatile, acid, and base/neutral fraction priority pollutants as a target component base. About 75 percent of these compounds are available as appropriate stable isotopically labeled analogs. Incorporating the stable labeled compounds as part of an analysis protocol is expected to decrease overall analysis costs by 30-70 percent when recommended quality assurance procedures are employed. Fundamental approaches to measurement parameter selection were identified which indicate the best ion fragment masses to measure, the best labeled compound spiking concentration, and the most appropriate data reduction methods.