title: Determination of perfluorinated alkyl acids in corn, popcorn and popcorn bags before and after cooking by focused ultrasound solid-liquid extraction, liquid chromatography and quadrupole-time of flight mass spectrometry.
abstract: An analytical method is proposed to determine ten perfluorinated alkyl acids (PFAAs) [nine perfluorocarboxylic acids (PFCAs) and perfluorooctane sulfonate (PFOS)] in corn, popcorn and microwave popcorn packaging by focused ultrasound solid-liquid extraction (FUSLE) and ultra high performance liquid chromatography (UHPLC) coupled to quadrupole-time of flight mass spectrometry (QTOF-MS/MS). Selected PFAAs were extracted efficiently in only one 10-s cycle by FUSLE, a simple, safe and inexpensive technique. The developed method was validated for microwave popcorn bags matrix as well as corn and popcorn matrices in terms of linearity, matrix effect error, detection and quantification limits, repeatability and recovery values. The method showed good accuracy with recovery values around 100% except for the lowest chain length PFAAs, satisfactory reproducibility with RSDs under 16%, and sensitivity with limits of detection in the order of hundreds picograms per gram of sample (between 0.2 and 0.7ng/g). This method was also applied to the analysis of six microwave popcorn bags and the popcorn inside before and after cooking. PFCAs contents between 3.50ng/g and 750ng/g were found in bags, being PFHxA (perfluorohexanoic acid) the most abundant of them. However, no PFAAs were detected either corn or popcorn, therefore no migration was assumed.
authors.affiliation: Department of Chemistry, University of La Rioja, C/ Madre de Dios 51, E-26006 Logroño, La Rioja, Spain. Electronic address: cristina.moreta@unirioja.es.
authors.forename: Cristina
authors.initials: C
authors.lastname: Moreta
authors.affiliation: Department of Chemistry, University of La Rioja, C/ Madre de Dios 51, E-26006 Logroño, La Rioja, Spain. Electronic address: maria-teresa.tena@unirioja.es.
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Tena
mesh_terms: D002264:Carboxylic Acids / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003296:Cooking; D017611:Fluorine Compounds / Q000032:analysis*; D008872:Microwaves; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*; D003313:Zea mays / Q000737:chemistry*
chemical_list: D002264:Carboxylic Acids; D017611:Fluorine Compounds
keywords: Focused ultrasound solid–liquid extraction; Liquid chromatography; Packaging; Perfluorinated alkyl acids; Popcorn; Quadrupole-time of flight mass spectrometry