title: UHPLC-MS/MS method for the quantitation of penicillin G and metabolites in citrus fruit using internal standards.
abstract: Penicillin G has been applied to citrus trees as a potential treatment in the fight against Huanglongbing (HLB). Here, we have developed and validated a method to identify and quantitate penicillin G and two of its metabolites, penillic acid and penilloic acid, in citrus fruit using ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). This method improves upon a previous method by incorporating isotopically labeled internal standards, namely, penillic acid-D5, and penilloic acid-D5. These standards greatly enhanced the accuracy and precision of our measurements by compensating for recovery losses, degradation, and matrix effects. When 2g of citrus fruit sample is extracted, the limits of detection (LOD) were determined to be 0.1ng/g for penicillin G and penilloic acid, and 0.25ng/g for penillic acid. At fortification levels of 0.1, 0.25, 1, and 10ng/g, absolute recoveries for penillic and penilloic acids were generally between 50-70%. Recoveries corrected with the isotopically labeled standards were approximately 90-110%. This method will be useful for the identification and quantitation of drug residues and their degradation products using isotopically labeled standards and UHPLC-MS/MS.
authors.affiliation: Florida Department of Agriculture and Consumer Services, Division of Food Safety, 3125 Conner Boulevard, Tallahassee, FL, 32399-1650, United States.
authors.forename: Daniele
authors.initials: D
authors.lastname: Canzani
authors.affiliation: Florida Department of Agriculture and Consumer Services, Division of Food Safety, 3125 Conner Boulevard, Tallahassee, FL, 32399-1650, United States.
authors.forename: Kevin
authors.initials: K
authors.lastname: Hsieh
authors.affiliation: Florida Department of Agriculture and Consumer Services, Division of Food Safety, 3125 Conner Boulevard, Tallahassee, FL, 32399-1650, United States.
authors.forename: Matthew
authors.initials: M
authors.lastname: Standland
authors.affiliation: Florida Department of Agriculture and Consumer Services, Division of Food Safety, 3125 Conner Boulevard, Tallahassee, FL, 32399-1650, United States.
authors.forename: Walter
authors.initials: W
authors.lastname: Hammack
authors.affiliation: Florida Department of Agriculture and Consumer Services, Division of Food Safety, 3125 Conner Boulevard, Tallahassee, FL, 32399-1650, United States. Electronic address: fadi.aldeek@freshfromflorida.com.
authors.forename: Fadi
authors.initials: F
authors.lastname: Aldeek
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000592:standards; D002957:Citrus / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry*; D057230:Limit of Detection; D016014:Linear Models; D010400:Penicillin G / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D012015:Reference Standards; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods* / Q000592:standards
chemical_list: D010400:Penicillin G
keywords: Huanglongbing (HLB); Internal standards; LC–MS/MS; Metabolites; Method development; Penicillin G