H Beilin, G Fireman
The foundation of Piaget's theories: mental and physical action
Advances in child development and behavior
per polyfluoroalkyl substances pfas class toxic environmental contaminants characterized high chemical stability enormous structural diversity limited availability pfas reference standards main motivation developing nontargeted analytical methods current concepts complex rely multiple filtering steps eg assumption homologous series detection mass defects generic fragments spectra obtained webbased sources highresolution mass spectrometry hrmsbased chromatograms fish liver extracts deconvoluted based ion abundance monoisotopic first isotopic peak number carbons c estimated extracted feature mass carbon mc mass defect carbon mdc ratio calculated pfasrelated peaks strongly discriminated matrix peaks plotting mc versus mdc enables nontarget detection pfas present low gkg concentration complex food matrixes proposed concept highly selective revealing relatively small number highprobability pfas candidates features small number surviving candidates permits msmsbased confirmation feature strategy led finding one pfas present reference standard solution well detection unexpected set pfas adducts proposed concept mass carbon versus mass defect carbon suited nontarget detection low amounts pfas complex matrixes capable detecting pfas fh ratio 11 regardless ionization mode