PMID- 17240909
OWN - NLM
STAT- MEDLINE
DCOM- 20070221
LR  - 20191210
IS  - 1464-0325 (Print)
IS  - 1464-0325 (Linking)
VI  - 8
IP  - 10
DP  - 2006 Oct
TI  - Development and comparison of methods using MS scan and selective ion monitoring 
      modes for a wide range of airborne VOCs.
PG  - 1029-42
AB  - Adsorbent sampling with analysis by thermal desorption, gas chromatography and 
      mass spectrometry (TD/GC/MS) offers many advantages for volatile organic 
      compounds (VOCs) and thus is increasingly used in many applications. For 
      environmental samples and other complex mixtures, the MS detector typically is 
      operated in the scan mode to aid identification of co-eluting compounds. However, 
      scan mode does not achieve the optimal sensitivity, thus compounds occurring at 
      low concentrations may not be detected. This paper develops and evaluates the 
      application of a more sensitive TD/GC/MS method using selective ion monitoring 
      (SIM) that is applicable to VOC mixtures found in ambient and indoor air. Based 
      on toxicity and prevalence, 94 VOCs (including terpenes, aromatic, halogenated 
      and aliphatic compounds) were selected as target compounds. Two analytical 
      methods were developed: a conventional full scan method for ions from 29 to 270 
      m/z; and a SIM method using 16 time windows and different ions selected for the 
      compounds in each window. Both methods used the same Tenax GR adsorbent sampling 
      tubes, TD and GC parameters, and target and qualifier ions. Laboratory tests 
      determined calibrations, method detection limits (MDLs), precisions, recoveries 
      and storage stability. Field tests compared scan and SIM mode analyses for 
      duplicate samples of indoor air in 51 houses and outdoor air at 41 sites. 
      Statistical analyses included the development of error/precision models. The 
      laboratory tests showed that most compounds demonstrated excellent precision 
      (<10% for concentrations exceeding approximately 0.5 microg m(-3)), good 
      linearity, near identical calibrations for scan and SIM modes, a wide dynamic 
      range (up to 1500 microg m(-3)), and negligible storage losses after 1 month (7 
      compounds showed moderate losses). SIM mode MDLs ranged from 0.004 to 0.27 microg 
      m(-3), representing a modest (1.1 to 22-fold) improvement compared to scan mode. 
      However, in field tests the SIM method detected significantly more compounds 
      (e.g., styrene and chloroform). Error models fit most compounds and allow 
      quantification of errors at selected percentiles. Overall, while the new SIM 
      method is somewhat time-consuming to develop, it offers greater sensitivity and 
      maintains the high selectivity of traditional scan methods.
FAU - Jia, Chunrong
AU  - Jia C
AD  - Environmental Health Sciences, University of Michigan, Ann Arbor, MI 48109-2029, 
      USA.
FAU - Batterman, Stuart
AU  - Batterman S
FAU - Chernyak, Sergei
AU  - Chernyak S
LA  - eng
GR  - R01-OH03692-06/OH/NIOSH CDC HHS/United States
PT  - Evaluation Study
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - England
TA  - J Environ Monit
JT  - Journal of environmental monitoring : JEM
JID - 100968688
RN  - 0 (Air Pollutants)
RN  - 0 (Organic Chemicals)
SB  - IM
MH  - Adsorption
MH  - Air Pollutants/*analysis
MH  - Air Pollution, Indoor/analysis
MH  - Environmental Monitoring/*methods
MH  - Gas Chromatography-Mass Spectrometry
MH  - Hot Temperature
MH  - Organic Chemicals/analysis
MH  - Volatilization
EDAT- 2007/01/24 09:00
MHDA- 2007/02/22 09:00
CRDT- 2007/01/24 09:00
PHST- 2007/01/24 09:00 [pubmed]
PHST- 2007/02/22 09:00 [medline]
PHST- 2007/01/24 09:00 [entrez]
AID - 10.1039/b607042f [doi]
PST - ppublish
SO  - J Environ Monit. 2006 Oct;8(10):1029-42. doi: 10.1039/b607042f.