Drug Screen, Prescription/OTC, Serum
Method Description Describes how the test is performed and provides a method-specific reference
Significant concentrations of many drugs can be extracted from aqueous weakly acidic (pH 4.0) solutions into a mixed organic phase of 80% chloroform, 20% ethyl acetate. After separation of the organic phase from the aqueous phase, the organic phase is dehydrated with anhydrous sodium sulfate and then evaporated. The residue containing concentrated drugs is redissolved in 100 L of pyridine/hexane, and an aliquot is subjected to gas chromatographic separation. Drugs present are identified by chromatographic retention time (gas chromatography) compared against a mixture of drug standards, and by structural analysis performed by mass spectrometry (GC/MS). (Foerster EH, Dempsey J, Garriott JC: A gas chromatographic screening procedure for acid and neutral drugs in blood. J Anal Toxicol 1979;3:87-91 as modified to incorporate some alkaline drugs by LE Ebnet and TP Moyer, Mayo Clinic)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday, Sunday; STAT availability 24/7
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test