title: Trace determination of free formaldehyde in DTP and DT vaccines and diphtheria-tetanus antigen by single drop microextraction and gas chromatography-mass spectrometry.
abstract: An immersed single drop microextraction (SDME) method was successfully developed for the trace enrichment of formaldehyde from DTP and DT vaccines and diphtheria-tetanus antigen. The formaldehyde was derivatized by means of the Hantzsch reaction. The dehydropyridine derivative was extracted into a microdrop of chloroform that suspended in a 4 ml sample solution for a preset time. The microdrop was then retracted into the microsyringe and injected directly into a gas chromatography-mass spectrometry (GC-MS) injection port. Effects of different parameters such as the type of solvent, extraction time, stirring rate, and temperature were studied and optimized. The limit of detection was 0.22 ng/l and relative standard deviation (RSD) value was 6.2% (n=5). The regression coefficient was satisfactory (r(2)=0.992) and linear range was obtained from 1 to 500 ng/l.
authors.affiliation: Environmental and Bio-Analytical Laboratories, Department of Chemistry, Sharif University of Technology, P.O. Box 11365-9516, Tehran, Iran. bagheri@sharif.edu
authors.forename: Habib
authors.initials: H
authors.lastname: Bagheri
authors.forename: Mahnaz
authors.initials: M
authors.lastname: Ghambarian
authors.forename: Amir
authors.initials: A
authors.lastname: Salemi
authors.forename: Ali
authors.initials: A
authors.lastname: Es-Haghi
mesh_terms: D000942:Antigens, Bacterial / Q000032:analysis / Q000737:chemistry; D004165:Diphtheria / Q000276:immunology; D022422:Diphtheria-Tetanus Vaccine / Q000032:analysis* / Q000737:chemistry; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000032:analysis* / Q000737:chemistry; D005557:Formaldehyde / Q000032:analysis* / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D012997:Solvents / Q000737:chemistry; D013742:Tetanus / Q000276:immunology
chemical_list: D000942:Antigens, Bacterial; D022422:Diphtheria-Tetanus Vaccine; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D012997:Solvents; D005557:Formaldehyde