Fall 2008 Newsletter
Case Study: Food Contamination Emergency
A food manufacturer noticed that their product had a strange odor after processing. It smelled like a cleaning product, and they were concerned that the batch was contaminated with a potentially toxic substance. Answers were needed quickly to prevent plant shutdown and production delays. They requested that Chemir analyze “good” vs. “bad” product samples for contaminants and perform a toxicity risk assessment. With millions of dollars of perishing inventory at stake, the results were needed over the weekend to prevent production downtime.
Analysis
Three analytical methods were used to compare the off-odor and control product samples, looking for chemical differences that would account for the strange odor. All three methods were used to analyze volatile materials from the control and suspect samples.
Static Headspace Gas Chromatography/Mass Spectrometry (GC/MS)
First, materials were analyzed by Headspace GC/MS. To prepare the samples, our scientists heated them in sealed containers to release potentially odiferous compounds. The gaseous headspace of the sealed container was then sampled directly. The Gas Chromatograph separated the components based on volatility and polarity, and then the Mass Spectrometer detected and identified the components. The fragmentation patterns obtained from the GC/MS analysis were used to identify the chemistries through library matching and spectral interpretation.
Purge and Trap GC/MS
An alternative technique, Purge and Trap GC/MS analysis, was also used to remove volatile components from the samples. The samples were warmed and an inert gas was bubbled through them. The purpose of this was to drive the volatile materials out of solution. The entire gas stream was then purged through a tube packed with an adsorbent material used to collect (trap) the volatile components. After a predetermined amount of purge time, the adsorbent material was heated to drive off the volatile components, introducing them into the GC/MS.
View a GC Chromatogram and Selected Odors Identified
Solid Phase Microextraction (SPME)
Lastly, our scientists used a sampling technique called Solid Phase Microextraction (SPME). This is a more sensitive extraction technique for most volatile components. Using this method, sample components were collected on a fiber coated with an appropriate material designed to adsorb volatile compounds. After a predetermined adsorption time, the fibers containing the volatile material were inserted into the injection port of the Gas Chromatograph where the volatiles were thermally desorbed and then analyzed. The mass spectral data was then collected and interpreted.
Results
Over 100 different compounds were detected in the off-odor food product, yet only 10 were of toxicological interest. Chemir Analytical Services worked closely with a toxicologist well versed in toxicity assessments. He reviewed the results and concluded that none of the compounds were present at a level of concern, and he provided a certificate to the manufacturer reporting these findings.
The client received their results on Monday morning and was able to resume operations on schedule. Chemir’s emergency analytical services and timely results, along with the toxicity risk assessment, saved the manufacturer from costly production downtime and product recalls. Moreover, the analysis assured the manufacturer there was not a toxic risk to the public.
Click here to learn more about Chemir's emergency services.