Results

1) Precision - assessed the precision of both the instrument(GC) and their method.

Instrumental precision: They injected 5, 10, and 20 mg/liter extracts of methaqualone, 10
times each. The %RSD ranged from 0.4% to 0.9%.

Method precision: Injecting a 10 mg/liter methaqualone standard( in serum) 23 times. The Standard deviation was 0.16mg/liter, with a %RSD of 1.6%.  
They also assessed day-to-day precision by injecting the same sample on 20 different days. The standard deviation was 0.5mg/liter, with a %RSD of 5.6%.


2) Stability

methaqualone in serum did not deteriorate when stored in room, refridgerator, freezer for a year.
PBCA in chloroform did not deteriorate when stored in room temp for a year.
both are relatively stable, this will not affect experimental readings.



3) Linearity and Sensitivity

linear response was found when 5-40mg/L of methaqualone in serum was used in FID(flame ionization detector)


4) Interference


They did a test to determine if any commonly used drugs that could be present in the serum would interfere with the credibility of the test.
They performed GLC with the drugs in the presence of methaqualone and the internal standard PBCA to see if these drugs affect the peak areas or symmetry of the methaqualone/PBCA peaks.
None of them showed any interference. However,they did not test the metabolites of the drugs.

Note: pentazocine, one of the drugs tested elutes close to PBCA, giving a tailing hump to the PBCA peak.
Under normal conditions, the maximum dosage of pentazocine is 0.16mg/liter which is too small to interfere with the experiment.