Gas Chromatography-Mass Spectrometry Analysis of Di-N-Octyl Disulfide in a Straight Oil Metalworking Fluid: Application of Differential Permeation and Box-Cox Transformation

Details

• Personal Author:
  Que Hee SS ; Xu W
• Description:
  The aim of this study was to identify and quantify an unknown peak in the chromatogram of a very complex mixture, a straight oil metalworking fluid (MWF). The fraction that permeated through a thin nitrile polymer membrane had less mineral oil background than the original MWF did at the retention time of the unknown peak, thus facilitating identification by total ion current (TIC) gas chromatography-mass spectrometry (GC-MS). The peak proved to be di-n-octyl disulfide (DOD) through retention time and mass spectral comparisons. Quantitation of DOD was by extracted ion chromatogram analysis of the DOD molecular ion (mass-to-charge ratio (m/z) 290), and of the m/z 71 ion for the internal standard, n-triacontane. Linear models of the area ratio (y) of these two ions versus DOD concentration showed a systematic negative bias at low concentrations, a common occurrence in analysis. The linear model of y(0.8) (from Box-Cox power transformation) versus DOD concentration showed negligible bias from the lowest measured standard of 1.51 mg/L to the highest concentration tested at 75.5 mg/L. The intercept did not differ statistically from zero. The concentration of DOD in the MWF was then calculated to be 0.398+/-0.034% (w/w) by the internal standard method, and 0.387+/- 0.036% (w/w) by the method of standard additions. These two results were not significantly different at p < or = 0.05. The Box-Cox transformation is therefore recommended when the data for standards are non-linear. [Description provided by NIOSH]
• Subjects:
  Mass Spectrometry Metals Metal Workers Mineral Oil Occupational Health Safety
• Keywords:
  Gas-chromatography Mass-spectrometry Mathematical-models Metalworking Metalworking-fluids Mineral-oils Models
• ISSN:
  0021-9673
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  California ; OSHA Region 9
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  25-31
• Volume:
  1101
• Issue:
  1
• NIOSHTIC Number:
  nn:20029709
• Citation:
  J Chromatogr A 2006 Jan; 1101(1-2):25-31
• Contact Point Address:
  Department of Environmental Health Sciences and UCLA Center for Occupational and Environmental Health, UCLA School of Public Health, 650 Charles Young Jr. Drive South, Los Angeles, CA 90095-1772, USA
• Email:
  xuwenhai@ucla.edu
• Federal Fiscal Year:
  2006
• Performing Organization:
  University of California Los Angeles
• Peer Reviewed:
  True
• Start Date:
  20000601
• Source Full Name:
  Journal of Chromatography A
• End Date:
  20040531
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:fe061bc005421030c78ec46f8f4adcf4d8a3d49cb83350e660c9db11954fe94b8066b7f2c521ef671d406d643e5dc6610345c5096788c931a94e33acb4e6ba06
• Download URL:
  https://stacks.cdc.gov/view/cdc/190634/cdc_190634_DS1.pdf
• File Type:
  [PDF - 181.74 KB ]