Originally Posted by Rusty22
peth was negative, whew !!
1) Is ets run always with etg or following a pos etg ?
also, 2) if one oz of etoh is consumed on friday, at 80 hours what
would you expect etg to be, likely well below 100, but some people
dont follow cut off values. 3) Thats the whole reason peth is recommended
by us labs.
EtS can only be tested for following a positive EtG if the EIA screen is being used, which in most cases it is. Why? Because there is currently no EIA available for EtS.
So the lab advertisements that offer the 2 for 1 test are simply playing on the purchasers ignorance of the 2-step testing process. If the screen is EtG negative then there was no test for EtS.
In fairness, if the purchaser is willing to pay for LC/MS, in other words skip the lower cost screen and go directly to the test usually used only in confirmation then both EtG and EtS can be detected simultaneously. That is seldom the case. 2)
Regardless of the instrumental setting EtG synthesized from one (1) oz of alcohol will not be present (let alone detectable) at 80 hours....not even at 24 hours. EtG and EtS are eliminated from the body just as the parent analyte EtOH. They have the same hydrophilic characteristic. These metabolites do not accumulate or secret in tissue like THC for instance. 3)
EtG, EtS and PEth do not operate on a comparable scale. The former are supposedly
direct metabolites created concurrently and immediately upon presentation of EtOH in the liver. PEth is a delayed pathological response to alcohol that occurs in blood and "requires 'sustained' drinking" over a period of time. The use of one to confirm the other would depend on the confluence of very unlikely events.
EtG testing has become a very lucrative field but the supporting science[?] has collapsed around it. So they introduced EtS as an "additive" without admitting the fallibility of EtG. The theory being that if both are present one confirms the other. Of course since they are created concurrently that is a ridiculous claim. But it keeps the money flowing. EtS has all of the major flaws as EtG so now the industry is introducing a third direct biomarker PEth.