Two-dimensional on-line detection of brominated and iodinated volatile organic compounds by ECD and ICP-MS after GC separation

Abstract

Inductively coupled plasma-mass spectrometry (ICP-MS) was coupled to a gas chromatographic (GC) system with electron capture detector (ECD), which enables relatively easy characterization and quantification of brominated and iodinated (halogenated) volatile organic compounds (HVOCs) in aquatic and air samples. The GC-ECD system is connected in series with an ICP-MS by a directly heated transfer line and an outlet port-hole for elimination of the ECD make-up gas during ignition of the plasma. The hyphenated GC-ECD/ICP-MS system provides high selectivity and sensitivity for monitoring individual HVOCs under fast chromatographic conditions. The ECD is most sensitive for the detection of chlorinated and brominated but the ICP-MS for iodinated compounds. The greatest advantage of the use of an ICP-MS is its element-specific detection, which allows clear identification of compounds in most cases. The absolute detection limits for ICP-MS are 0.5 pg for iodinated, 10 pg for brominated, and 50 pg for chlorinated HVOCs with the additional advantage that calibration is almost independent on different compounds of the same halogen. In contrast to that detection limits for ECD vary for the different halogenated compounds and lie in the range of 0.03-11 pg. The two-dimensional GC-ECD/ICP-MS instrumentation is compared with electron impact mass spectrometry (EI-MS) and microwave induced plasma atomic emission detection (MIP-AED). Even if EI-MS has additional power in identifying unknown peaks by its scan mode, the detection limits are much higher compared with GC-ECD/ICP-MS, whereas the selective ion monitoring mode (SIM) reaches similar detection limits. The MIP-AED detection limits are at the same level as EI-MS in the scan mode.

Inductively Coupled Plasma–Mass Spectrometry (ICP-MS) for Quantitative Analysis in Environmental and Life Sciences: A Review of Challenges, Solutions, and Trends

“…The transfer of brominated as well as iodinated or chlorinated volatile organic compounds from different environmental compartments into the atmosphere, where their decomposition due to photochemical reactions takes place, is strongly related to the ongoing reduction of the tropospheric ozone layer. Within this background a two-dimensional on-line detection scheme for brominated, iodinated, and chlorinated volatile organic compounds has been developed using GC hyphenated to an electron capture detector (ECD) and ICP-MS. 129 Under optimized conditions ECD showed lower detection limits for the measured halogens (below 1 pg); however, with only ECD detection it was not possible to distinguish between co-eluting species that contain different halogens. Seawater samples from the North Sea have been analyzed with respect to quantification of the different halogenated volatile organic compounds, released into the water phase or the atmosphere by seaweed or algae.…”

Fast speciation analysis of iodophenol compounds in river waters by capillary electrophoresis‐inductively coupled plasma‐mass spectrometry with off‐line solid‐phase microextraction

“…In this case, an important difference was obtained regarding the optimal carrier gas flow rate with constant iodine introduction and flow injection sample introduction were performed. The best results for continuous iodine sample introduction were obtained with 1.1 L?min 21 argon carrier flow rate. However, an argon carrier flow rate of 0.95 L?min 21 was optimal when transient signals were monitored.…”

“…The best results for continuous iodine sample introduction were obtained with 1.1 L?min 21 argon carrier flow rate. However, an argon carrier flow rate of 0.95 L?min 21 was optimal when transient signals were monitored. Transient signals are more influenced by changes in the carrier gas flow rates, producing a higher signal dilution when higher flows are utilized.…”

“…The fiber was initially conditioned at 3007C in a GC injector inlet for 120 min, according to the manufacturer's recommendations to remove contaminants and avoid passive extraction of analytes from the sample. The SPME procedure was performed as follows: 10 mL volume of water sample was adjusted to pH 2 with HCl and sodium chloride was added to make the salt concentration 1 mol?L 21 . The sample was placed in a 20 mL glass sample vial.…”

“…High-per-formance liquid chromatography coupled to inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) [9][10][11][12][13][14][15][16][17][18] is the most widely used hyphenated technique for the analysis of iodine. Other methodologies used for speciation of iodine in the past include coupling capillary electrophoresis [19,20] or gas chromatography (GC) to ICP-MS [21]. An approach for the analysis of iodophenols in drinking water was recently developed using gas chromatography-mass spectrometry (GC-MS) and gas chromatography with electron capture detection (GC-ECD) [8].…”