The analysis of airborne aldehydes and ketones first involves collection of the analytes by passing air through a cartridge containing 2,4-dinitrophenylhydrazine (DNPH). As the air passes through the cartridge, the analytes react with the DNPH to form hydrazones which are immobilized on the cartridge. The cartridges are then eluted with solvent and the DNPH derivatives…
IV bag components were analyzed for extractables using direct thermal desorption/thermal extraction combined with a unit mass resolution GC/MSD system. The results were compared to those obtained for leachables by stir bar sorptive extraction of an aqueous simulant stored in the exact same type of IV bag, again combined with GC/MS determination of the leached…
Rubber particles, sometimes derived from used tires, are used on artificial turf athletic fields, on playgrounds and as mulch. These particles can off-gas and leach compounds into the environment and may present a contact or inhalation hazard. Recent news reports in the US and Europe indicate a growing concern regarding potential health effects in athletes…
The influence of variations in desorption temperature, desorption fl ow and sample preparation on VDA 278 analysis method [1] robustness and reproducibility is studied using a wide variety of samples from automobile interior materials: polypropylene (PP) granulate, polyurethane (PU) foam, leather, Duroplastic plastics and paint. It is shown that a temperature difference of just two…
An automated analysis system consisting of a dynamic headspace (DHS) system coupled with thermal desorption-Gas Chromatography/ Mass Spectrometry (TD-GC/MS) was used for fully automated microscale chamber material emission analysis of Spray Polyurethane Foam (SPF). Closed-cell and opencell SPF samples were analyzed for emissions of TVOCs and high boiling compounds such as, for example, fl ame…
An automated micro-scale chamber method based on 2,4-dinitrophenylhydrazine (DNPH) derivatization and Tenax TA adsorption, for sampling formaldehyde, acetaldehyde, acetone, acrolein, as well as volatile organic compounds (VOCs) was developed. Following the sampling step, the Tenax TA tubes were immediately transferred to a thermal desorption (TD)-GC/MS system for analysis. The DNPH tubes were transferred to an…
The analysis of airborne aldehydes and ketones first involves collection of the analytes by passing air through a cartridge containing 2,4-dinitrophenylhydrazine (DNPH). As the air passes through the cartridge, the analytes react with the DNPH to form hydrazones which are immobilized on the cartridge. The cartridges are then eluted with solvent and the DNPH derivatives…
A new fully automated thermal desorption (TD)-GC/MS method was developed for determination of formaldehyde and other airborne carbonyls as well as VOCs for material emission testing. The method includes an automated in-situ derivatization agent loading step prior to every sampling step, thus blank values are avoided. Pentafluorophenylhydrazine (PFPH) was used as derivatization agent and was…
This study describes the use of the GERSTEL MultiPurpose Sampler (MPS) fitted with a Thermal Desorption Unit (TDU) and a Cooled Injection System (CIS 4) PTV-type Inlet for the automated direct thermal extraction analysis of packaging for three different brands of crème-fi lled chocolate sandwich cookies, cheese-filled sandwich crackers and soft and chewy candy. Download…
Electron Paramagnetic Resonance (EPR) measures the concentration and composition of free radicals in a sample. Samples can be either liquid, solid or gas. Free radicals are atomic or molecular species with unpaired electrons that can be highly reactive. There are also many stable free radicals, such as melanin in hair and ultramarine blue pigment. Many…
Asphaltene concentration can be easily measured by ESR once a calibration curve has been made. The calibration curve made using an asphaltene powder dissolved in toluene. The ESR spectra of the various concentrations of apshaltene powder used to make the calibration curve. Active Spectrum has software that will automatically measure the concentration of an unknown…
Refining of hydrocarbons and vegetable oils typically includes hydrogenation. In a refinery hydrogen consumption is a major cost issue, and percent hydrogen content is used as an important indicator of refining progress. Hydrogen content at the endpoint is one of the specifications that needs to be met for products like jet fuel and diesel. An…
There has been an increase in concern for the detection and removal of organic chloride species from crude aromatic, naphtha, and other hydrocarbon streams. One process called catalytic reforming uses organic chloride to condition the catalyst, which results in lowlevel chloride contamination downstream. This can take the form of hydrogen chloride (HCl) and organic chlorides.…
Natural gas and other gaseous fuels naturally contain varying amounts and classes of sulfur compounds, which can be odorous, corrosive to equipment, and inhibit or destroy catalysts used in gas processing. Even trace amounts of sulfur can be destructive to processing. Sulfur is also added in small amounts, 1 to 4 ppmv, to natural gas…
Natural gas and other gaseous fuels naturally contain varying amounts and classes of sulfur compounds, which can be odorous, corrosive to equipment, and inhibit or destroy catalysts used in gas processing. Even trace amounts of sulfur can be destructive to processing. Sulfur is also added in small amounts, 1 to 4 ppmv, to natural gas…
ASTM D5623 is a method primarily for the determination of volatile sulfur-containing compounds in light petroleum liquids with a final boiling point of 230 °C or lower at atmospheric pressure, such as petroleum distillates and gasoline. Many sulfur compounds in light petroleum liquids are odorous, can cause corrosion to equipment, inhibit or destroy catalysts, and…
Some of the key processes in the petrochemical industry are conversions of high-grade ethylene (C2) and propane/propylene (C3) feedstocks into end products (polyethylene, polypropylene) and intermediates such as 1-butene. These are the building blocks for plastics and a wide range of products, and are a large industry, with 55 million metric tons of polypropylene produced…
High purity benzene is key in numerous chemical manufacturing processes. Even very small amounts of thiophene in benzene can poison catalysts making the determination of trace level amounts essential to the petroleum industry. ASTM Method D7011 covers the determination of thiophene in refined benzene using gas chromatography and sulfur selective detection. This application note presents…