Effects of sorbent materials on the cryofocusing analysis of gaseous reduced sulphur compounds

Abstract

The relative performance of different sorbent materials employed in the cryofocusing (e.g. in cold trap (CT) unit) stage was investigated at sub-ambient temperature by the thermal desorption (TD)-gas chromatography (GC)-pulsed flame photometric detector. To this end, the TD-based calibration of five reduced sulphur compounds (RSC: H2S, CH3SH, CS2, DMS and DMDS) and SO2 was carried out via the Peltier cooling system with five types of sorbent combinations such as two single-bed (Tenax TA and Silica gel) plus three multibed types (a combination of either two from the following three sorbents: Tenax TA, Silica gel and Carbopack B). Relative performance of each of all five CT options, if evaluated in terms of response factors for each compound, demonstrated that each CT composition acts as an important criterion to distinguish detection properties between light and heavy sulphur species. Although the relative response of H2S and CH3 SH was systematically distinguishable between the CT types, that of SO2 was the most complicated to interpret. According to this study, the two CT types consisting of Carbopack B and Silica gel (CS-0.4 and CS-0.6) were the optimum choices for sulphur gas analysis in terms of basic QA parameters (sensitivity, reproducibility and linearity).

Hydrogen Purity Analysis: Suitability of Sorbent Tubes for Trapping Hydrocarbons, Halogenated Hydrocarbons and Sulphur Compounds

“…COS and CS 2 are notoriously difficult to trap and require the trapping to be performed at low temperatures (at least −5 • C) on very strong sorbents for example carbon molecular sieves, such as Carbosieve SIII [19][20][21][22]. Some promising results have been obtained using Carbotrap 301 for COS. Tenax TA together with Carboxen 1000 has been shown [23] to be a possible alternative for trapping methyl mercaptan, ethyl mercaptan, dimethyl sulphide, COS and CS 2 .…”

Deodorization of food-related nuisances from a refrigerator: The feasibility test of photocatalytic system

“…In addition to GC and spectrophotometer based analysis, air dilution sensory (ADS) test was performed based on the olfactometry threshold method by diluting odor samples with odorless pure air to determine the dilution-to-threshold ratio (D/T ratio) values. Detailed information of analytical procedures regarding the following targets [20][21][22][23] …”