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.
The best thing about a mouth swab drug test or spit test is that itâs very easy for marijuana smokers to pass. Thatâs because marijuana can only be detected in the system by a spit test for 12 to 24 hours. Compare this to other common drugs: 1  Cocaine: 1 day.f you know ahead of time the best way to pass a mouth swab drug test is to stop smoking weed for a day or two prior to taking the test. Be sure to brush your teeth thoroughly and use mouthwash daily too. The randomness of the saliva drug test is its main strength, however.