Materials being investigated by thermal sampling techniques such as pyrolysis are frequently polymeric, but they may also have volatile and semi-volatile contaminants and additives. When using pyrolysis- gas chromatography, these non-polymeric constituents produce some of the most significant peaks in the chromatogram. It has become common to perform two or more analyses on the sample at increasing temperatures, to remove the additives before pyrolysis. Often, analysis of the polymer structure is less important than the nature and amount of additives present, especially those additives known to be hazardous.
Restriction of Hazardous Substances, or RoHS, began in the European Union and restricts the use of specific hazardous materials found in electrical and electronic products. Businesses which sell these products may be subjected to RoHS requirements if they use restricted substances. The RoHS 3 with a deadline of July 22, 2019 requires the disclosure of the following 4 phthalates: Bis(2-Ethylhexyl) phthalate (DEHP), Benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), Diisobutyl phthalate (DIBP). These phthalates are typically used as insulation plasticizers and are on the European Chemicals Agency REACH list of SVHC (Substances of Very High Concern).
In addition, the International Electrotechnical Commission (IEC) published a standard method for determining phthalates in electronic equipment. IEC 62321-8 defines approaches to determine previously mentioned DEHP, DIBP, BBP, DBP, as well as additional phthalates, di-n-octyl phthalate (DNOP), di-isononyl phthalate (DINP) and di-iso-decyl phthalate (DIDP) in electronics, by GC-MS and TD-GC-MS. The TD-GC-MS method involves two separate thermal desorption heating ramps for one GC run. This can be performed using a CDS 6000 Series Pyroprobe Autosampler. TIC and extracted ion chromatograms in Figure 1 match the chromatograms in Annex C.2 of the International Standard.
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