3H2A9-THC

In order to perform quantitation, the four steps listed above are preceeded by the addition of 3H2A9-THC to the plasma. This is achieved in order to allow accurate determination of the quantity of A9-THC initially present, by correcting the non negligible losses observed during extraction, esterification and purification as shown schematically in Figure 2. 

In order to check the identical nature of both behaviors, i.e. the absence of isotopic effects, yields were estimated for two amounts of A9-THC (500 and 5 ng) corresponding to two distinct zones of the standard curve (r = 40 and r = 4000 respectively), with the same quantity (1 ng) of 3h2A9-THC. The values obtained show that 3H2A9-THC incorporated does not modify the R variations already described, since the yield is 17.5% in the first case and 49.5% in the second. In addition, it should be noted that although the amount of 1 ng 3H2A9-THC can be ignored in relation to 500ng, the same does not apply to the lower limit of sensitivity for which the result must take into account the presence of the tritiated addition. 

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