Gas chromatographic determination of polychlorinated biphenyls (as Aroclor 1254) in serum: collaborative study.

A gas chromatographic-electron capture detection method for determining the concentration of polychlorinated biphenyls (PCBs) as Aroclor 1254 (AR 1254) in serum was evaluated through a 2-phase collaborative study. In Phase I, each collaborator's lot of Woelm silica gel (70-150 mesh) was evaluated for elution and recovery of AR 1254, which had been added in vitro at 25 ng/mL to a serum extract. In Phase II, each collaborator analyzed a series of bovine serum samples that contained the following: (1) in vitro-spiked AR 1254; (2) in vivo AR 1254 and 8 in vitro-spiked chlorinated hydrocarbons; (3) in vivo AR 1254 only; (4) 8 in vitro-spiked chlorinated hydrocarbons only; and (5) neither AR 1254 nor chlorinated hydrocarbons above the detection limit of the method.

Standardization of lipid and lipoprotein determinations for pediatric screening procedures.

Standardization of lipid and lipoprotein measurements is of concern to laboratories that serve pediatric as well as adult populations, since preventive measures taken during pediatric years can help control atherosclerotic cardiovascular problems that can arise during adult years. Multiple analytical and physiologic problems that exist inherently in the lipids and lipoproteins and in application of measurements to the pediatric population must be controlled to gain standardization and produce highly precise and accurate results. Reference values from well-described, observed pediatric populations have been published for use in interpreting analytical results.