title: Rapid screening and quantification of glucocorticoids in essential oils using direct analysis in real time mass spectrometry.
abstract: There is a strong demand to develop a method capable of rapid screening for the adulteration of glucocorticoids (GCs) in cosmetics. An ambient ion source- direct analysis in real time (DART), coupled with quadrupole time of flight mass spectrometry (QTOF MS) was used for the rapid screening of GCs in essential oils.
  
  
  
  Liquid-liquid extraction was employed prior to the DART-QTOF MS analysis. Calibration curves for eight GCs were obtained using methyltestosterone as an internal standard. MS/MS experiments and accurate mass measurements were carried out to provide reliable and powerful evidence for the adulteration of targeted GCs.
  
  
  
  Quantification results were obtained in terms of linearity (R(2) for all GCs, 0.986-0.996), sensitivity (limit of detection, 2.0-50 ng/mL), and repeatability (RSD, 1.2-6.0%). The entire analytical process can be finished in 5 min, compared with the GC/MS or LC/MS methods for which typical analysis times range from tens of minutes to >1 h. In addition, comparison of the performance of DART and ESI ion sources showed that DART possessed a relatively low matrix effect when handling complex samples.
  
  
  
  A new method for the rapid screening and quantification of GCs in essential oils was developed using DART-QTOF MS. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P.R. China.
authors.forename: Jialing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P.R. China.
authors.forename: Ze
authors.initials: Z
authors.lastname: Li
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P.R. China.
authors.forename: Zhigui
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P.R. China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P.R. China.
authors.forename: Huwei
authors.initials: H
authors.lastname: Liu
mesh_terms: D002138:Calibration; D003358:Cosmetics / Q000032:analysis; D005938:Glucocorticoids / Q000032:analysis*; D057230:Limit of Detection; D059625:Liquid-Liquid Extraction; D013058:Mass Spectrometry / Q000379:methods*; D009822:Oils, Volatile / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D003358:Cosmetics; D005938:Glucocorticoids; D009822:Oils, Volatile