Göran Gellerstedt

Paper products physics and technology

The production of forestry products is based on a complex chain of knowledge in which the biological material wood with all its natural variability is converted into a variety of fiber-based products, each one with its detailed and specific quality requirements. This four volume set covers the entire spectrum of pulp and paper chemistry and technology from starting material to processes and products including market demands. Supported by a grant from the Ljungberg Foundation, the Editors at the Royal Institute of Technology, Stockholm, Sweden coordinated over 30 authors from university and industry to create this comprehensive overview. This work is essential for all students of wood science and a useful reference for those working in the pulp and paper industry or on the chemistry of renewable resources.

9. Analytical Methods

The purpose of this chapter is to describe the analytical methods that are available for detecting, measuring, and/or monitoring polybrominated biphenyls (PBBs) and polybromintaed diphenyl ethers (PBDEs), its metabolites, and other biomarkers of exposure and effect to PBBs and PBDEs. The intent is not to provide an exhaustive list of analytical methods. Rather, the intention is to identify well-established methods that are used as the standard methods of analysis. Many of the analytical methods used for environmental samples are the methods approved by federal agencies and organizations such as EPA and the National Institute for Occupational Safety and Health (NIOSH). Other methods presented in this chapter are those that are approved by groups such as the Association of Official Analytical Chemists (AOAC) and the American Public Health Association (APHA). Additionally, analytical methods are included that modify previously used methods to obtain lower detection limits and/or to improve accuracy and precision. PBBs and PBDEs are analyzed in environmental and biological samples by methods quite similar to those used for polychlorinated biphenyls (PCBs) (de Kok et al. 1977; Fries 1985b; Pomerantz et al. 1978). The analytical methods for PBBs were developed primarily in the 1970s, whereas analytical methods for PBDEs were developed very recently. In the 30 years between analytical efforts directed at PBBs and PBDEs, there have been many advances in the technology and costs of analytical instruments. Thus, while gas chromatography-electron capture detection (GC-ECD) with packed columns (i.e., noncongener specific) was the primary analytical technique used in the 1970s for PBBs, gas chromatography-mass spectrometry (GC-MS) with capillary columns (i.e., congener specific) is the primary analytical technique now used for PBDEs. These points should be considered when comparing the differences and quality of analysis for these two classes of compounds. Covaci et al. (2003) recently reviewed the determination of brominated flame retardants, with emphasis on PDBEs in environmental and human samples. The analysis methodology for PBBs and PBDEs includes several steps: sample collection and storage, sample pretreatment, extraction, cleanup and fractionation, and analytical determination. Care must be taken to assure that the sample collection follows quality-assurance protocols and that equipment and containers are free from contamination. It is important that laboratories utilize blanks when reporting trace levels of PBBs and PBDEs. This practice will minimize the influence of trace contamination samples that can originate from a variety of sources.