PubMed Health⌕ Search

PubMed · 707413

Evaluation of non-core laboratories.

Abstract

The CAP Interlaboratory Survey data from the non-core laboratories identified by Paule and Mandel were examined. Some laboratories were designated non-core because they submitted one or more values that were widely discrepant and were caused by unit problems, decimal shifts, or reversal of the specimens. A second group of laboratories submitted a number of discrepant results that appeared to be caused by problems within the laboratories. A third group submitted results that appeared acceptable, and the exclusion and the effectiveness of the criteria differed for each of the three analytes. The findings suggest that examination of data from excluded laboratories can provide a valuable source of information to supplement the central data.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

R K Gilbert, L Sheehan. 1978. Evaluation of non-core laboratories.. https://pubmed.ncbi.nlm.nih.gov/707413/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Detection of Delta9-tetrahydrocannabinolic acid A in human urine and blood serum by LC-MS/MS.

Delta9-tetrahydrocannabinolic acid A (Delta9-THCA-A) is the precursor of Delta9-tetrahydrocannabinol (Delta9-THC) in hemp plants. During smoking, the non-psychoactive Delta9-THCA-A is converted to Delta9-THC, the main psychoactive component of marihuana and hashish. Although the decarboxylation of Delta9-THCA-A to Delta9-THC was assumed to be complete--which means that no Delta9-THCA-A should be detectable in urine and blood serum of cannabis consumers--we found Delta9-THCA-A in the urine and blood serum samples collected from police controls of drivers suspected for driving under the influence of drugs (DUID). For LC-MS/MS analysis, urine and blood serum samples were prepared by solid-phase extraction. Analysis was performed with a phenylhexyl column using gradient elution with acetonitrile. For detection of Delta9-THCA-A, the mass spectrometer (MS) (SCIEX API 365 triple-quadrupole MS with TurboIonSpray source) was operated in the multiple reaction monitoring (MRM) mode using the following transitions: m/z357 --> 313, m/z357 --> 245 and m/z357 --> 191. Delta9-THCA-A could be detected in the urine and blood serum samples of several cannabis consumers in concentrations of up to 10.8 ng/ml in urine and 14.8 ng/ml in serum. The concentration of Delta9-THCA-A was below the Delta9-THC concentration in most serum samples, resulting in molar ratios of Delta9-THCA-A/Delta9-THC of approximately 5.0-18.6%. Only in one case, where a short elapsed time between the last intake and blood sampling is assumed, the molar ratio was 18.6% in the serum. This indicates differences in elimination kinetics, which need to be investigated in detail.

Blood Chemical Analysis↗