Tungsten coil electrothermal matrix decomposition and sample vaporization to determine P and Si in biodiesel by inductively coupled plasma mass spectrometry

Author(s)

Donati, George L. ^[1] ; Amais, Renata S. ^[1] ; Nobrega, Joaquim A. ^[1]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Chem, Grp Appl Instrumental Anal, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Journal of Analytical Atomic Spectrometry; v. 28, n. 2, p. 280-287, FEB 2013.
• Web of Science Citations: 17

Abstract

A tungsten coil extracted from commercially available microscope light bulbs is used to decompose the organic matrix and vaporize biodiesel samples for P and Si determination by electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS). The vaporization cell is connected to a modified sheath gas tube so that sample vapors are mixed with a continuous aerosol flow exiting the ICP-MS nebulization chamber. Helium and H-2 are used with a collision reaction interface (CRI) to minimize spectral interferences and obtain low baseline spectra. These strategies contribute to improving repeatability and accuracy. A small solid state constant current power supply is used to resistively heat the vaporizer and 10 mu l sample aliquots are introduced manually on the coil with a micropipette. Limits of detection of 0.4 and 0.1 mg kg(-1) are obtained for P and Si, respectively. Reference biodiesel samples are used to check the accuracy of the procedure for P. A spike experiment is carried out to assess accuracy in Si determinations. No statistically significant differences are observed for reference and determined values by applying a t-test at a 95% confidence level. The direct analysis of biodiesel by tungsten coil ETV-ICP-MS is a fast and effective alternative to determine challenging elements like P and Si. (AU)

• FAPESP's process: 10/50238-5 - Determinacao de fosforo, enxofre e silicio em biodiesel usando espectrometro de massa acoplado ao plasma induzido com interface de colisao e reacao
• Grantee: George Luis Donati
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 06/59083-9 - Inductively coupled plasma mass spectrometry: fundamentals and applications
• Grantee: Joaquim de Araújo Nóbrega
• Support Opportunities: Research Projects - Thematic Grants
• 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