An acute taste and odour episode solved by olfactory GC-MS

Abstract

This paper details the analytical strategy that was used to understand the origin of an acute taste and odour episode that induced the temporary shutdown of a plant serving several million customers in South America. The odour of the drinking water was described by local people as "olive odour". The odour of a first sample was described as green apple, fruity and olive oil by CIRSEE panellists. LLE and CLSA-GC/MS showed that the sample contained high levels of 2,4-ditertbutylphenol. When submitted to olfactory-GC/MS, the LLE extract revealed the presence of an intense sweet-fruity odour that did not match any of the MS peaks. Investigation of a second, more concentrated sample collected during the peak of the episode finally revealed that this main odour was due to 2-ethyl-5,5-dimethyl-1,3-dioxane (2EDD). The cis and trans isomers of 2-ethyl-4-methyl-1,3-dioxolane (2EMD) were also identified, together with a variety of plastic additives or oligomers. These compounds had been spilled by a polyester resin manufacturing plant. The characteristics of these episodes are compared with the rare similar episodes previously reported in the literature.

Odor in Relation to Different Polymers

“…73 Odor episodes were detected in drinking water in South America which was traced to pollution from a polyester production plant. 74 The water samples contained high levels of 2,4-di-tert-butylphenol. 74 When submitted to olfactory-GC/MS, the extract revealed the presence of an intense sweet-fruity odor.…”

Reasons for Odor Formation in Plastic Materials

“…7 Panelists were able to smell ETBE at a concentration of 5 g/L. 8 In the case of PVC pipe some amounts of hexanal, octanal, nonanal and decanal were detected. 9 The quantitative threshold odor number, TON, for PVC pipe was zero, unlike in the case of HDPE and PEX pipes, where TONs were higher than 5.…”

“…7 The odor of the drinking water was described by local people as "olive odor". 8 The odor of a sample was described as green apple, fruity, and olive oil by panelists. 8 GC/MS showed that the sample contained high levels of 2,4-di-tert-butylphenol, which is a degradation product of frequently used antioxidant.…”

“…8 The odor of a sample was described as green apple, fruity, and olive oil by panelists. 8 GC/MS showed that the sample contained high levels of 2,4-di-tert-butylphenol, which is a degradation product of frequently used antioxidant. 8 High density polyethylene, crosslinked polyethylene, and polyvinyl chloride pipes for drinking water were tested with respect to migration of volatile organic components to water.…”

“…8 GC/MS showed that the sample contained high levels of 2,4-di-tert-butylphenol, which is a degradation product of frequently used antioxidant. 8 High density polyethylene, crosslinked polyethylene, and polyvinyl chloride pipes for drinking water were tested with respect to migration of volatile organic components to water. 9 It was found that HDPE pipe causes formation of odor because of migration of 2,4di-tert-butyl-phenol, which is a known degradation product of antioxidants, such as Irgafos 168.…”