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Autofluorescence as a Parameter to Study Pharmaceutical Materials
Published in Victoria Vladimirovna Roshchina, Fluorescence of Living Plant Cells for Phytomedicine Preparations, 2020
Victoria Vladimirovna Roshchina
Among xenobiotics in plant cells, fluorescent pesticides may be found; for example, pesticidal carbamates acting on cholinesterases of both animals and plants (Addison et al. 1977). In addition, carbamates offer the possibility of determining their influence on cholinesterase activity. As early as 1992, Mueller and coworkers presented a list of fluorescent herbicides that could potentially be used in diagnostics. The fluorescence properties of 39 herbicides representing several major types of chemistry were determined. The fluorescence of analytical standards was measured in acetonitrile, acetonitrile + water, and acetonitrile + water + strong acid. Fourteen of the 39 herbicides fluoresced to some extent, and seven (bentazon, chloramben, difenzoquat, fluometuron, imazaquin, 2-methyl-4-chlorophenoxyacetic acid [MCPA], and norflurazon) were identified as good candidates for further method development. Herbicides or their derivatives have been detected with spectrofluorometric methods in various matrices, including fluometuron and its metabolites in soil to 20 ng/g soil, asulam (methyl[(4-aminophenyl)sulfonyl]carbamate) in spinach, and glyphosate ((N-phosphonomethyl) glycine) and its metabolite in natural water. This technique has also been employed to identify other pesticides, such as the methylcarbamates in food, carbaryl (1-naphthyl-N-methylcarbamate) in honeybees or honey, and thiabendazole and carbendazim in various crops. The bipyridiniums fluoresced in acetonitrile very strongly. However, addition of water to the solutions of diquat and paraquat totally quenched the observed fluorescence. Additionally, diquat and paraquat are only very slightly soluble in acetonitrile (but very water soluble), and this would hinder method development. It should be noted that this method has not so far been used for histochemical analysis in plant cells in situ. Only chlorophyll fluorescence is recommended for analysis as a marker for herbicides (Dayan and de Zaccaro 2012).
Enhanced fluorescent sensing probe via PbS quantum dots functionalized with gelatin for sensitive determination of toxic bentazon in water samples
Published in Drug and Chemical Toxicology, 2022
Farzaneh Marahel, Leila Niknam
Herbicides are classes of agricultural pesticides for products that improve in quality Salman and Hameed (2010). Toxic bentazon is the common name for the herbicide 3-isopropyl-1H-2,1,3-benzothiadiazin-4-(3H)-one 2, 2-dioxide and is used as a post-emergence herbicide to control broadleaf and sedges in agriculture beans, rice, corn, peanuts, and mint Fuhrmann et al. (2014); Mir et al. (2014). It is a contact toxic herbicide, which means that it only functions in the part of the plant where it is applied and its activity is short-lived Bruzzoniti et al. (2016); Hedegaard et al. (2018). Since toxic bentazon is the widely applied herbicide, monitoring and determination of bentazon in ground and surface waters and in cultivated areas where it is used are of high significance. GC and LC methods Guan et al. (2010). HPLC Pinto and Jardim (1999); Takla et al. (2020), and LC-ESI-MS/MS Cho et al. (2017), were used for the determination of bentazon. All these determinations were time-consuming and required expensive chemicals, equipment, and sample preparation.