REDUCING THE PHTHALATES CONTAMINATION DURING THE ANALYSIS PROCESS USING GAS PURGE MICROSYRINGE EXTRACTION.

Phthalate esters (PAEs) are commonly used as non-reactive plasticizers in vinyl plastics to increase the flexibility of plastic polymers . Numerous studies reported about the PAEs as a class of endocrine-disrupting chemicals . In addition, these studies also showed that a major source of human exposure to phthalates is the diet . To date, the largest problem in PAEs analysis is the contamination due to the wide and uncontrolled PAE presence in the environment, including chemicals and glassware: sample contamination may then occur in every step of the analysis process. To reduce the possibility of contamination during sample handling, it is then necessary to shorten the pretreatment step, and to keep the analysis procedure as simple as possible. Gas purge microsyringe extraction (GP-MSE) is a fast technique, suitable for miniaturization, with no plastic components in the whole device that works under a nitrogen flow, and it can be considered a good candidate to reach this goal. In fact, with GP-MSE a new and low-blank-value analytical method for the analysis of PAEs in foodstuffs was set-up. The overall recoveries ranged from 85.7 to 102.6%, and the RSD was less than 10%. This method has been applied in the monitoring of PAEs in 78 foodstuffs. The results showed that a wide variety of PAE concentrations were found in the different groups, and the highest content of PAEs (in the range 658 - 1610 ng g-1 fresh weight) was found in seafood. The concentration values found in food were in the following order: DEHP > DBP > DEP ≈ DMP > BBP ≈ DNOP. Finally, the daily intake of PAEs was estimated for adults based on the levels of PAEs in foodstuffs. The total estimated daily intakes of PAEs, calculated in terms of DEHP amount, ranged from 3.2 and 12.9 mg kg-1 bw d-1.