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P Tundo

Publications and source records attributed to P Tundo.

9 recordsLinked to original sources
PubMed2006

Monitoring of polychlorinated dibenzo-p-dioxins and dibenzofurans, dioxin-like PCBs and polycyclic aromatic hydrocarbons in food and feed samples from Ismailia city, Egypt.

Concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyl (PCBs) and polycyclic aromatic hydrocarbons (PAHs) have been determined using GC/HRMS in food (butter, seafood and meat) and feed samples (chicken, cattle and fish) purchased from Ismailia city, Egypt. PCDD/F concentrations in food samples ranged between 0.12 and 3.35 pg WHO TEQ/g wet w, while those in feed samples were between 0.08 and 0.2 pg WHO TEQ/g dry w. Levels of PCB TEQ ranged from 0.14 to 3.2 pg/g wet w in the food samples. The feed samples have an average of 0.35 pg PCB TEQ /g dry w. In this study, butter samples showed the highest contamination levels of PCDD/Fs and PCBs. The PCBs contribution to the total TEQ was on average 63% in seafood and on average 49% for meat and butter. The highest contamination levels of PCDD/Fs and PCBs were found in butter samples. The butter TEQ content is several times higher than that reported in all EU countries and exceeded the EU limits, while the PCDD/F levels in seafood and the feed samples is far below the current EU limit. Generally, congener profiles in the food samples reflect the non-industrialized nature of the city and suggest solid waste burning as a significant source of emission. Nevertheless, the profiles for butter suggest an impact from various sources. In the case of the sum of 16 PAH contamination levels in food samples were in the range of 11.7-154.3 ng/g wet w and feed samples had a range of 116-393 ng/g dry w. Benzo(a)pyrene (BaP) has been detected in the range of 0.05-3.29 ng/g wet w in the food samples; butter showed the highest contamination which exceeded the EU standard set for fats and oil. Fingerprints of PAHs suggested both petrogenic and pyrolytic sources of contamination.

Animal Feed↗
PubMed2006

Dietary intake of dioxins and dioxin-like PCBs, due to the consumption of dairy products, fish/seafood and meat from Ismailia city, Egypt.

Although dietary intake studies have been carried out extensively in most developed countries, to evaluate the health risks of PCDD/Fs and DL-PCBs, no data of this kind exists for Egypt. In this study, concentrations of PCDD/Fs and DL-PCBs were measured using HRGC/HRMS in the most contributing foodstuffs (dairy products, fish/seafood, and meat) randomly collected from Ismailia city, Egypt. The dietary intake of PCDD/Fs and DL-PCBs were subsequently determined, and compared with the most recent studies. To provide a primary estimation of the whole TEQ intake in Egypt if all the main food categories included, an estimation of the dietary intake (based on EU data) for some important and non-measured groups (cereals, vegetables/fruits, eggs and milk) was carried out. The calculated dietary intake based on the WHO assumption of 60 kg bw ranged from 3.69 to 4.0 pg WHO-TEQ/kg bw/day for PCDD/Fs and from, 6.04 to 6.68 pg WHO-TEQ/kg bw/day, if DL-PCBs were included. PCBs intake contributed about 40% of the total TEQ intake. Dairy products (mainly cheese) were the main contributor to the intake of PCDD/Fs (89%), while fish/seafood and meat have more or less the same percent share (5.4%). The dairy products contamination was the reason for our elevated dietary intake, as the content of PCDD/Fs and DL-PCBs is several times higher than in all the developed countries. The total intake (PCDD/Fs+DL-PCBs) due to consumption of dairy products, fish/seafood and meat, is close to that reported in EU countries at the beginning of 1980s, but much higher than all those mentioned in all the recent reports, and higher than the maximum WHO TDI of 4 pg TEQ/kg bw/day. A recalculation of the dietary intake to include not only our measured data but also the data for the non-measured groups, yielded a total intake in the range of 4.06-6.38 pg TEQ/kg bw/day for PCDD/Fs and a range of 6.59-9.98 pg TEQ/kg bw/day for total including PCBs. Results show that cereals and vegetables/fruits contribute significantly to PCDD/Fs TEQ intake in Egypt and play a more important role than fish/seafood and meat. This is the case even though the intake for cereals and vegetables/fruits based on EU data.

Animals↗
PubMed2001

Reaction of primary aromatic amines with alkyl carbonates over NaY faujasite: a convenient and selective access to mono-N-alkyl anilines.

At atmospheric pressure and at 130-160 degrees C, primary aromatic amines (p-XC6H4NH2, X = H, Cl, NO2) are mono-N-alkylated in a single step, with symmetrical and asymmetrical dialkyl carbonates [ROCOOR', R = Me, R' = MeO(CH2)2O(CH2)2; R = R' = Et; R = R' = benzyl; R = R' = allyl; R = Et, R' = MeO(CH2)2O(CH2)2], in the presence of a commercially available NaY faujasite. No solvents are required. Mono-N-alkyl anilines are obtained with a very high selectivity (90-97%), in good to excellent yields (68-94%), on a preparative scale. In the presence of triglyme as a solvent, the mono-N-alkyl selectivity is independent of concentration and polarity factors. The reaction probably takes place within the polar zeolite cavities, and through the combined effect of the dual acid-base properties of the catalyst.

Journal Article↗
PubMed2001

Dimethylcarbonate for eco-friendly methylation reactions.

Dimethylcarbonate (DMC), an environmentally friendly substitute for dimethylsulfate and methyl halides in methylation reactions, is a very selective reagent. Both under gas-liquid phase transfer catalysis (GL-PTC) and under batch conditions, with potassium carbonate as the catalyst, the reactions of DMC with methylene-active compounds (arylacetonitriles and arylacetoesters, aroxyacetonitriles and methyl aroxyacetates, benzylaryl- and alkylarylsulphones) produce monomethylated derivatives, with a selectivity not previously observed (i.e., >99%). The highly selective O-methylation of phenols and p-cresols by DMC is also attained by a new methodology using a continuous fed stirred tank reactor (CSTR) filled with a catalytic bed of polyethyleneglycol (PEG) and potassium carbonate.

Carbonates↗