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In this study, natural deep eutectic solvents (NADESs) were used as both the extraction and dilution matrix in static headspace gas chromatography-mass spectrometry (SHS-GC-MS) for the analysis of volatile components in Ipomoea cairica (L). Sweet (ICS) leaves. Six NADESs were prepared and the NADESs composed of choline chloride and glucose with a 1:1 molar ratio containing 15% water were preferred due to the better peak responses. A total of 77 volatiles in ICS leaves were detected and tentatively identified by mass spectral matching with the US National Institute of Standards and Technology (NIST, 2014) Mass Spectral Library and the retention index-assisted qualitative method. These 77 volatile components were mainly terpenoids, aromatics, and aliphatics. Among them, ß-elemene, ß-caryophyllene, α-humulene, and 2, 4-di-tert-butylphenol were found to be the main components. This investigation verified that the use of NADESs is an efficient green extraction and dilution matrix of the SHS-GC-MS method for direct volatile component analysis of plant materials without extra extraction work.

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Haloacetic acids (HAAs) are formed during the process of water disinfection. Therefore their presence in foods can be correlated with the addition of or contact with treated water. To determine the origin of HAAs in milk and dairy products, firstly a chromatographic method was developed for their determination. The sample treatment involves deproteination of milk followed by derivatization/extraction of the HAAs in the supernatant. About 20% of the foods analyzed contained two HAAs - which in no case exceeded 2 µg L(-1), that can be ascribed to contamination from sanitizers usually employed in the dairy industry. The process of boiling tap water (containing HAAs) for the preparation of powdered infant formula did not remove them; therefore it would be advisable to prepare this type of milk with mineral water (free of HAAs). In addition, it is possible to establish if the milk has been adulterated with treated water through the determination of HAAs.

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Water used in a food factory is frequently disinfected with chlorine, which originates disinfection by-products: haloacetic acids (HAAs) make up the second most prevalent class of these products. In this paper we propose the first static HS-GC-MS method developed for direct HAA determination in beverages; the method has higher sensitivity, simplicity and reliability than the only alternative available in the literature. From 150 beverages analysed, it is possible to conclude that at least 2 HAAs (dichloro- and trichloroacetic acids, DCAA and TCAA) are always present in beverages prepared with treated water, which remains constant for 2 or 3 months in the beverages. Moreover, beverages of 100% fruit juices and soft drinks prepared with mineral water (free of HAAs) do not contain any HAA at significant values. Therefore, DCAA and TCAA may indicate of the presence of treated water in beverages.

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OBJECTIVE: Atractylodes macrocephala, a famous herbal medicine, is used extensively in the practice of Traditional Chinese Medicine (TCM). Processing procedure is a common approach that usually occurs before A. macrocephala is prescribed. This paper describes a sensitive and specific assay for the determination of principal volatile compounds in crude and processed A. macrocephala. MATERIALS AND METHODS: The present study concentrated on the development of a static headspace gas chromatography-mass spectrometry (SHS-GC/MS) for separating and identifying of volatile compounds from crude and processed A. macrocephala samples. RESULTS: The results showed that the volatile oil in crude and processed A. macrocephala was markedly quantitatively and qualitatively different. Processing resulted in the reduction of volatile oil contents and variation of chemical compositions in A. macrocephala. CONCLUSION: The proposed method proved that SHS-GC/MS is rapid and specific, and should also be useful for evaluating the quality of crude and processed medicinal herbs.

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A simple and efficient method has been developed for the extraction and determination of sixteen common volatile halogenated disinfection by-products (DBPs) using the static headspace (HS) technique coupled with gas chromatography-mass spectrometry (GC-MS). The DBPs determined included trihalomethanes (THMs), halonitromethanes (HNMs) and haloacetonitriles (HANs). The extraction parameters (HS conditions, ionic strength and organic modifier) were studied in order to obtain the highest sensitivity. Under optimum conditions (water containing 250 µL of methyl tert-butyl ether and 6g of anhydrous sodium sulphate was heated 20 min at 80°C), the HS-GC-MS method provides limits of detection between 10 and 200 ng/L and a relative standard deviation of ∼5.6%. Samples collected from genuine tap water treated with different oxidising agents (ClO2/Cl2, Cl2/NH2Cl and O3/Cl2) in several disinfection treatment plants were successfully analysed in order to establish their effect on the occurrence of DBPs. In parallel, the influence of the main parameters of the water (pH, conductivity, nitrite, nitrate, free residual chlorine, permanganate oxidability and bromide) was also studied. The results suggest that the permanganate oxidability (related to organic matter) and the bromide concentration as well as disinfection conditions are directly related to the occurrence of THMs, HNMs and HANs, both in their concentrations and speciation. The method developed was compared to the reference EPA Method 551.1 for the analysis of tap water.

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