Proteins, nucleic acids are best example of natural polymers. Similarly cellulose is also a natural polymer which acts as main structural component of plants. Usually natural polymers are composed by condensation polymerisation with the elimination of water molecule.
Drug-Laboratory Test Interactions. False-positive urine immunoassay screening tests for phencyclidine (PCP) and amphetamine have been reported in patients taking venlafaxine. This is due to lack of specificity of the screening tests. False positive test results may be expected for several days following discontinuation of venlafaxine therapy. Confirmatory tests, such as GC/MS will clear that misconception up asap...or if you are not using pcp and your dr is sceptical.
If itâs positive-dilute, there was still a sufficient amount of drug in the urine to produce a positive result, so itâs still a positive. If itâs negative-dilute, however, thatâs often a different story. A common way to pass a drug test is to consume mass quantities of water so that urine runs clear. This can often be enough to pass a drug test, even if there are drugs in a donorâs system.