The ionic composition of interstitial and intravascular fluids is the same. Proteins, however, are kept with the vascular compartment, at least to a degree, by the vascular wall, which is a semi-permeable membrane. The concentration of proteins is much higher in the plasma sector than in the interstitial sector.
Detection of marijuana using swab drug test can vary from person to person taking into account the different conditions like general health, different fluid intake, metabolism, etc.
Drug Test Detection Times. Drug tests detect not only drugs but metabolites as well. Metabolites are the byproducts of a substance after it has run through your system. To determine whether you will pass or not, it is important to know how much of the illicit metabolites are in your urine, as well as the test âcut off,â or Level of Detection (LOD). Usually marijuana tests will have a cutoff of 50ng/mL, but it can be as low as 25ng/mL. Home testing can tell you whether your level at the time of the test is above or below the 50ng/mL level, but it will not tell you the exact level of THC metabolites in your system.