title: Increasing the instrumental throughput of gas chromatography method using multiple injections in a single experimental run: application in determination of friedelan-3-ol and friedelin in Maytenus ilicifolia.
abstract: The aim of this study was to develop a separation method using multiple injections in a single experimental run (MISER) employing gas chromatography with flame ionization detection (GC-FID) for the first time, without instrument modification, to increase the instrumental throughput. The method was applied to the determination of the triterpenes friedelan-3-ol and friedelin in a plant extract obtained from Maytenus ilicifolia leaves. The column used in the chromatography system was a ZB-50 (30 m × 0.25 mm × 0.15 μm) with 50% phenyl-50% methyl-polysiloxane. The samples (1.0 μL) were injected using the split mode (1:90), with the injector at 280 °C and FID detector at 320 °C. The column temperature was programmed to isothermal mode at 300°C. Helium was used as the carrier gas with a constant flow of 1.5 mL min(-1). It was possible to perform three injections in the same run using the MISER method. An increase in the instrumental throughput by a factor of around 2.6 was observed when the use of multiple injections was compared with the single injection method. This method showed good linearity for both analytes with R(2)>0.99 and the values for the limit of detection were 0.24 mg L(-1) and 0.44 mg L(-1), for friedelan-3-ol and friedelin, respectively. Furthermore, the values for the limits of quantification were 0.79 mg L(-1) for friedelan-3-ol and 1.16 mg L(-1) for friedelin. The proposed method has potential for other GC applications, allowing an increase in the instrumental throughput of the methods by applying this separation technique.
authors.affiliation: Department of Chemistry, Federal University of Santa Catarina, 88040-900 Florianopolis, SC, Brazil.
authors.forename: Jacqueline Pereira
authors.initials: JP
authors.lastname: Vistuba
authors.forename: Marcel
authors.initials: M
authors.lastname: Piovezan
authors.forename: Moacir Geraldo
authors.initials: MG
authors.lastname: Pizzolatti
authors.forename: Andrey Martinez
authors.initials: AM
authors.lastname: Rebelo
authors.forename: Mônia Stremel
authors.initials: MS
authors.lastname: Azevedo
authors.forename: Luciano
authors.initials: L
authors.lastname: Vitali
authors.forename: Ana Carolina Oliveira
authors.initials: AC
authors.lastname: Costa
authors.forename: Gustavo
authors.initials: G
authors.lastname: Amadeu Micke
mesh_terms: D005410:Flame Ionization / Q000379:methods*; D057230:Limit of Detection; D029755:Maytenus / Q000737:chemistry*; D010936:Plant Extracts / Q000302:isolation & purification; D018515:Plant Leaves / Q000737:chemistry; D014315:Triterpenes / Q000302:isolation & purification*; D000094042:Lupanes
chemical_list: D010936:Plant Extracts; D014315:Triterpenes; C419506:friedelan-3-ol; C060796:friedelin; D000094042:Lupanes