A: High molecular weight compounds that have a noticeable scent. Vanilla would be a possibility.
Q: Have you determined an analytical detection/quantitation limit (using SIM and MSD) for TBA? If yes, what did you determine?
A: We have not determined an analytical detection limit. However, since we are performing the analysis on the headspace above the sample, it is difficult to determine the true concentration in the sample. The TBA concentration in the headspace is dependent on how well TBA is desorbed or emitted from the sample.
Q: Have you ever studied TBA transmission through plastics? Do you have any data on TBA transmission for various plastics?
A: To date, we have not studied the transmission of TBA through various plastics. Consequently, we do not have any data. However such studies are possible for us to perform if requested by the customer
Q: Would you expect a higher reading of TBA in the accumulators used to test for TBA in the air?
A: The concentration measured from the SPME fiber in the air is dependent on the TBA air concentration and the length of time the fiber is exposed to the air. The measured concentration would need to be adjusted for the exposure time.
Q: Is there an allowable limit for TBA in the Pharma industry?
A: Based on the information in the literature, there is no allowable limit because TBA is non-toxic.
Q: How does the odor distill from a pallet into bottles through the carton and bottle?
A: TBA is a highly volatile compound that can permeate through the packaging and the plastic. These are porous materials. Since TBA has a very low odor threshold, a concentration greater than 50 parts per quadrillion can be sensed olfactorally.
Q: What is the training of the person who does the "sniffing"?
A: The people performing the sniffing are chemists who have many years of experience in analytical chemistry, along with a significant amount of exposure to aromal odor analysis.
Q: Was this testing procedure used by J&J in their recent situation with the Tylenol brand?
A: We have used this type of testing procedure with many companies to determine tba. However due to confidentiality, we cannot specify the companies that have employed the services of Microanalytics.
Q: Why do your olfactory results show multiple lines?
A: One curve represents the analytical result from the gas chromatograph. While the other curve represents the aromagram generated by the scientist at the sniff port.
The combination of these two anlaysees is what makes our technology so unique and accurate.
Q: How does the identification occur if there is zero MS signal?
A: Since the mass spectrometer signal is at the instrumental background, initial identification of TBA occurs with the olfactory detector (nose). The concentration of the TBA in the headspace is below the detectable level of the mass spectrometer. However, the scientist can focus on the area where the off-odor occurs. In order to confirm the identification, the concentration of the compound needs to increase. This can be performed through longer collection times, heartcutting in the gas chromatograph, cryotrapping and backflushing the column.
Q: Does quantification require authentic standard dilutions to parts per quadrillion? (any issues with this...)
A: We have not pursued “true” quantification since our analysis measures the TBA concentration in the headspace from the sample. There is no way to determine the distribution of TBA between the sample and the headspace.
Q: Is using a fiber more accurate than taking a sample with a syringe?
A: Using a SPME fiber allows the sample from the headspace to be preconcentrated prior to analysis in the gas chromatogram. The length of time the fiber is exposed to the headspace can be increased. While for a syringe, only a given volume of headspace can be analyzed.
Q: Are there procedures that can be done to increase the sensitivity of the GC/MS analysis?
A:To increase the sensitivity of the GC/MS analysis, the concentration of the compound of interest needs to increase. This can be performed through longer collection times, heartcutting in the gas chromatograph, cryotrapping and backflushing the column.
Q: TBA can be identified by odor, so people would probably not consume edible products, but is the compound harmful at that level?
A: Based on the information that we have found, there is no allowable limit because TBA is non-toxic.
Q: Can samples be submitted at this time if we suspect contamination? Submission Process? Cost?
A: Samples can be submitted for analysis at this time.
Please contact Guy Wray at Mocon or your local Mocon sales representative.
We will have a conference call to discuss your analytical needs, discuss the types of samples to be collected, discuss how the samples should be handled, etc. This will allow us to provide an accurate price quote for your analysis. 763-493-6370
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