Discussion

The authors found that it was necessary to synthesize an internal standard-PBCA as it gives the best results.
Why?
1) drugs cant be used as internal standards because of self interefence.(they contain methaqualone)
2) non drug compounds eluted in the same position as methaqualone.
3) other compounds had retention times that were too long or too short. Retention times can affect the resolution and symmetry of the peaks.


Confirming peak signals
They performed their method on a column packing containing a different liquid stationary phase. (3% OV-17)
3% OV-17 on 80/100 mesh Chromosorb W (HP) packing can be used to confirm positive results for the 3% OV-1 packing.
(which is what their method is using as a liquid phase)

Note: Figure 3 is a chromatogram of methaqualone in serum using their method and a 3% OV-1 packing.
Figure 7 is a chromatogram of methaqualone in serum using their method but a 3% OV-17 packing.

Why is OV-17 not used as a liquid phase for their method?

OV-17 is used for this test and not for the method because
1) increased time needed to elute the sample.
2) higher chance of interference from other drugs.
3) peaks eluting very near or in the same area as methaqualone or the internal standard.


Conclusion

This method is reliable, time-saving and can be done by someone with little GC experience.
Also, it can quantify the amount of methaqualone in a patient within 15 minutes after receiving the patient sample.