Determination of P, S and Si in biodiesel, diesel and lubricating oil using ICP-MS/MS

Author(s)

Amais, Renata S. ^[1] ; Amaral, Clarice D. B. ^[1] ; Fialho, Lucimar L. ^[1] ; Schiavo, Daniela ^[2] ; Nobrega, Joaquim A. ^[1]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Chem, Grp Appl Instrumental Anal, BR-13560 Sao Carlos, SP - Brazil

^[2] Agilent Technol, Sao Paulo - Brazil

• Document type: Journal article
• Source: ANALYTICAL METHODS; v. 6, n. 13, p. 4516-4520, 2014.
• Web of Science Citations: 34

Abstract

The feasibility of inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) to overcome polyatomic interferents in severely affected isotope determination is demonstrated here. This instrument arrangement presents an octopole reaction/collision system (ORS) in between two quadrupole mass analyzers. The first quadrupole operates as a mass filter which allows just the target mass-to-charge ratio (m/z) to enter the ORS and rejects all other species with m/z different from the target analyte's m/z. Once in the ORS, analytes react with the reaction gas introduced into the ORS, and the second quadrupole selects the product of the reaction's m/z (mass shift operation mode). We describe here a procedure for accurate determination of P, S and Si in biodiesel, diesel and lubricating oil by ICP-MS/MS. Fuel standard reference materials (SRMs) were microwave-assisted acid-digested using nitric acid and hydrogen peroxide. The oxygen gas flow rate in the ORS was optimized considering the limit of detection (LOD) values and accuracies reached for P, S and Si determinations in the lubricating oil SRM and the best oxygen gas flow rate was 0.75 mL min(-1). Adopting optimized conditions, limits of detection were 1.2, 0.49, 0.31, 0.33 and 0.78 mu g L-1 for (SiO+)-Si-28-O-16, (SiO+)-Si-29-O-16, (PO+)-P-31-O-16, (SO+)-S-32-O-16 and (SO+)-S-34-O-16, respectively. Adequate precision, accuracy and sensitivity were obtained when using the mass shift mode and recoveries for biodiesel, diesel and lubricating oil digests ranged from 95.0 to 113%. No significant differences were observed between the certified values and the ones obtained using ICP-MS/MS at a 95% confidence level. (AU)

• FAPESP's process: 10/17387-7 - Assessment of spectroanalytical techniques and sample preparation procedures for the determination of sulfur in biodiesel and diesel blends
• Grantee: Renata Stábile Amais
• Support Opportunities: Scholarships in Brazil - Doctorate