A kind of sensitive, rapid, and simple spectrophotometry based on a Ytterbium(Yb3+) functionalized gold nanoparticle(Au NPs-Yb) was developed for detection of organophosphorus pesticides(OPs). Prepared AuNPs possess o...A kind of sensitive, rapid, and simple spectrophotometry based on a Ytterbium(Yb3+) functionalized gold nanoparticle(Au NPs-Yb) was developed for detection of organophosphorus pesticides(OPs). Prepared AuNPs possess oxygen-containing functional groups and strong complexation reaction with Yb3+. While oxygen-containing thiophosphate in the OPs molecule can combine with Yb3+as a cross-linking molecule to produce insoluble yetterbium phosphate, resulting in the aggregation of AuNPs and great decrease in ultraviolet absorbance strength at 520 nm by ultraviolet visible(UV-vis) spectrophotometer. Under the optimized conditions, a linear relationship between the absorbance of AuNPs and OPs concentration ranged from 0.05 μg/L to 6.0 μg/L with limit of detection for 0.03 μg/L(S/N = 3), which is far lower than the maximum residue limit(0.01 ppm) in the European Union pesticides database. Therefore, this assay has potential application in the determination of OPs in the field of environmental and food monitoring.展开更多
Baking meat by wrapping them in Aluminum (Al) foil is common in many countries. The excessive use of Al foil in baking and the disagreement about using Al foils were the motivation to do this study especially after th...Baking meat by wrapping them in Aluminum (Al) foil is common in many countries. The excessive use of Al foil in baking and the disagreement about using Al foils were the motivation to do this study especially after the 2007 WHO/FDA Report. In this investigation, a gravimetric and a UV-Vis spectrophotometric method are used to estimate Aluminum (Al) leaching into meat baked by wrapping in Al foil. Three kinds of meat were used fish, cow stakes and chicken. The importance of Al exposure area was neglected by many studies. Five factors affecting Al leaching into meat are studied (baking temperature, baking time, additives, Al exposure area and weight of meat). The effect of cooking times (20, 40, 60 minutes) at 180℃ and cooking temperatures (160℃, 180℃, 200℃) at 60 minutes on the amount of Al leaching were evaluated. It was found that Al leaching into meat increased with increasing temperature, baking time, additives and Al exposure area. Moreover, Al exposure area was more effective than the weight of the meat. The Al leaching was highest in fish and lowest in chicken. Comparing the present results with the Provisional Tolerance Weekly Intake of Al approved by WHO/FDA, it shows that Al leaching into meat baked by wrapping in Al foil may add considerable doses into the diet. Continuous monitoring of Al foil used for baking meat is recommended.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.21765015,21808099,21765018)the Jiangxi Province Food and Drug Administration Science Foundation,China(No.2016SP04)
文摘A kind of sensitive, rapid, and simple spectrophotometry based on a Ytterbium(Yb3+) functionalized gold nanoparticle(Au NPs-Yb) was developed for detection of organophosphorus pesticides(OPs). Prepared AuNPs possess oxygen-containing functional groups and strong complexation reaction with Yb3+. While oxygen-containing thiophosphate in the OPs molecule can combine with Yb3+as a cross-linking molecule to produce insoluble yetterbium phosphate, resulting in the aggregation of AuNPs and great decrease in ultraviolet absorbance strength at 520 nm by ultraviolet visible(UV-vis) spectrophotometer. Under the optimized conditions, a linear relationship between the absorbance of AuNPs and OPs concentration ranged from 0.05 μg/L to 6.0 μg/L with limit of detection for 0.03 μg/L(S/N = 3), which is far lower than the maximum residue limit(0.01 ppm) in the European Union pesticides database. Therefore, this assay has potential application in the determination of OPs in the field of environmental and food monitoring.
文摘Baking meat by wrapping them in Aluminum (Al) foil is common in many countries. The excessive use of Al foil in baking and the disagreement about using Al foils were the motivation to do this study especially after the 2007 WHO/FDA Report. In this investigation, a gravimetric and a UV-Vis spectrophotometric method are used to estimate Aluminum (Al) leaching into meat baked by wrapping in Al foil. Three kinds of meat were used fish, cow stakes and chicken. The importance of Al exposure area was neglected by many studies. Five factors affecting Al leaching into meat are studied (baking temperature, baking time, additives, Al exposure area and weight of meat). The effect of cooking times (20, 40, 60 minutes) at 180℃ and cooking temperatures (160℃, 180℃, 200℃) at 60 minutes on the amount of Al leaching were evaluated. It was found that Al leaching into meat increased with increasing temperature, baking time, additives and Al exposure area. Moreover, Al exposure area was more effective than the weight of the meat. The Al leaching was highest in fish and lowest in chicken. Comparing the present results with the Provisional Tolerance Weekly Intake of Al approved by WHO/FDA, it shows that Al leaching into meat baked by wrapping in Al foil may add considerable doses into the diet. Continuous monitoring of Al foil used for baking meat is recommended.
基金the National Natural Science Foundation of China(5117214451372153)+2 种基金Science Technology Foundation of shanghai(12410710300)Leading Academic Discipline Project of Shanghai Municipal Education Commission(J51503)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning