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Dilution

What is Dilution?

Dilution refers to the process of a donor reducing the acidic content of their urine specimen by excessive fluid consumption with the deliberate goal of manipulating a urine test in order to achieve a negative test result. Many employers follow a dilution protocol covering an immunoassay test, representing an initial screen where a dilute specimen in question requires further testing for comparative analysis to support or refute the original test findings. 

Although dilution carries suspicious implications, a urine specimen is unable to quantitatively measure recent consumption or impairment since the body can metabolize different drugs at a variable rate. Thus, residual traces can suggest regular drug use. In lab testing settings, technicians examine creatinine levels, which contribute to enzymatic processes involved with muscle homeostasis, gauging the proportionate amount of creatinine found in urine against baseline cutoff values to mark solubility, which indicates dilution. Moreover, specific gravity is an additional testing procedure that explains the relative density of a urine specimen, matching its concentration grade against the standard of water with predetermined values that help confirm dilution. 

Since immunoassays tend to furnish loose analyses when evaluating drug test results, a complementary battery of testing measures known as gas chromatography-mass spectrometry (GC-MS) alongside liquid chromatography-mass spectrometry(LC-MS) can override cutoff threshold variances. The GC-MS/LC-MS protocol targets and isolates drug metabolites found in the system, cross-referencing the suspected analytes against the tabulated criteria of drug classes and their derivative compounds, highlighting their cutoff thresholds. Though immunoassays are calibrated with a high cutoff marker to avoid a false positive, a diluted specimen raises circumstantial factors where extensive testing is necessary to level disparities between an initial positive test result and subsequent findings. 

In Canada, dilution is a common problem that individuals often misuse to divert suspicions of recent drug use, compelling employers to administer comprehensive urine drug testing aligned with health and safety guidelines.

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