RESUMO
Glyphosate is a highly effective, low-toxicity, broad-spectrum herbicide, which is extensively used in global agriculture to control weeds and vegetation. However, glyphosate has become a potential threat to human and ecosystem because of its excessive usage and its bio-concentration in soil and water. Herein, a novel turn-on fluorescent probe, N-n-butyl-4-(3-pyridin)ylmethylidenehydrazine-1,8-naphthalimide (NPA), is proposed. It efficiently detected Cu2+ within the limit of detection (LOD) of 0.21 µM and displayed a dramatic turn-off fluorescence response in CH3CN. NPA-Cu2+ complex was employed to selectively and sensitively monitor glyphosate concentrations in real samples accompanied by a fluorescence turn-on mode. A good linear relationship between NPA and Cu2+ of glyphosate was found in the range of 10-100 µM with an LOD of 1.87 µM. Glyphosate exhibited a stronger chelation with Cu2+ than NPA and the system released free NPA through competitive coordination. The proposed method demonstrates great potential in quantitatively detecting glyphosate in tap water, local water from Songhua River, soil, rice, millet, maize, soybean, mung bean, and milk with mild conditions, and is a simple procedure with obvious consequences and no need for large instruments or pretreatment.
Assuntos
Técnicas Biossensoriais , Glicina/análogos & derivados , Herbicidas/isolamento & purificação , Naftalimidas/química , Cobre/química , Corantes Fluorescentes/química , Glicina/química , Glicina/isolamento & purificação , Glicina/toxicidade , Herbicidas/química , Herbicidas/toxicidade , Humanos , Limite de Detecção , Pontos Quânticos/química , Rios/química , Poluentes do Solo/isolamento & purificação , Poluentes do Solo/toxicidade , Água/química , Poluentes da Água/isolamento & purificação , Poluentes da Água/toxicidade , GlifosatoRESUMO
Objective To investigate the basic distribution of endemic areas in the type of drinking water arsenism and in Xiantao City,Hubei Province,and to offer a scientific basis for control and prevention.Methods According to"the Chinese Scheme of Implementing Surveillance of Distribution of Endemic Arsenism",considering with the special geography feature of Xiantao,both sampling and overall survey were used in 7 towns chosen.The water arsenic content was determined by half quantitative fast reagent-box method.We began to search for clues and patients according to the endemic areas and the families with high arsenic wells.Results High endemic arsenic water sources were distributed in 7 the towns(districts or farms).In 81 villages of Xiantao City,35 villages had drinking water arsenic content exceeding 0.05 mg/L,accounting for 43.21%(35/81).In 4020 screened wells,269 had arsenic content higher than the national standard,the detective rate of high arsenic wells(more than 0.05 mg/L)was 6.69%(269/4020),with the highest rate in Shahu Seed Plant being 13.56%(115/848).The population exposed to high arsenic was 1091,in a rate of 5.75%(1091/18 975),in which 281 children were exposed in a rate of 5.82%(281/4826).In Shahu Seed Plant,467 people including 129 children were exposed to high arsenic, accounting for 13.26%(467/3522)and 12.91%(129/999),respectively.Conclusions High arsenic sources widely exist in Xiantao City,especially in Shahu Seed Plant,where arsenic content,the exposed rate of population and children are high.Therefore,prevention and control should be carried out in the southeast as soon as possible,as well as in other places where situation is less serious.
