title: Determination of metalaxyl and identification of adjuvants in wettable powder pesticide technical formulas.
abstract: Foliar runoff is one of the most important processes affecting off-target movement of fungicides. In this way, Ridomil Gold Plus and Ridomil Gold MZ are two types of wettable powder technical formulations which contain metalaxyl and they are used for such a purpose. A method for quantitative determination of metalaxyl in pesticide formulas has been developed, validated, and subsequently applied to Ridomil Gold Plus and Ridomil Gold MZ. The method employs liquid-liquid extraction followed by liquid chromatography coupled with UV detection (LC-UV), using gas chromatography coupled with mass spectrometry as confirmation technique and to carry out a screening of organic adjuvants of these two selected pesticide formulas. Metalaxyl of 26.5 and 41 g/kg was detected in Ridomil Gold Plus and Ridomil Gold MZ, close to the manufacture specified level of 25 and 40 g/kg, respectively. Activator and utility adjuvants were detected in these two wettable powder technical formulations. Only methyl-ester-based surfactants were found within the group of nonionic surfactants, but the long-term fates of most adjuvants in soils and elsewhere in the environment are largely unknown, partially because of the lack of long-term monitoring data.
authors.affiliation: Nutrition and Bromatology Group, Analytical and Food Chemistry Department, Faculty of Food Science and Technology, University of Vigo, Ourense Campus, 32004 Ourense, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Pose-Juan
authors.forename: Raquel
authors.initials: R
authors.lastname: Rial-Otero
authors.forename: Elena
authors.initials: E
authors.lastname: Martínez-Carballo
authors.forename: Eugenio
authors.initials: E
authors.lastname: López-Periago
authors.forename: Jesús
authors.initials: J
authors.lastname: Simal-Gándara
mesh_terms: D000277:Adjuvants, Pharmaceutic / Q000032:analysis* / Q000145:classification; D000409:Alanine / Q000031:analogs & derivatives* / Q000032:analysis; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D002853:Chromatography, Liquid; D008401:Gas Chromatography-Mass Spectrometry; D006863:Hydrogen-Ion Concentration; D055601:Organic Chemistry Phenomena; D010575:Pesticides / Q000737:chemistry*; D011208:Powders; D012997:Solvents; D013056:Spectrophotometry, Ultraviolet; D017155:Wettability
chemical_list: D000277:Adjuvants, Pharmaceutic; D010575:Pesticides; D011208:Powders; D012997:Solvents; C028175:metalaxyl; D000409:Alanine