Ashing method potential problems

The impact of extraneous inorganic matter on the analysis cannot be predicted. Most chemical analysis methods have been optimized for bark-free wood that has an ash content of less than 2 percent. These methods may not be applicable to herbaceous materials where structural silica can increase the ash content to more than 15 percent of the dry weight of the biomass. One potential problem with high ash samples is that inorganic materials, depending on their composition, may neutralize the sulfuric acid solutions used in the hydrolysis steps. The affect of pH changes... 

Until a few years ago landfill disposal has been the favored method of disposing of laboratory wastes. Because of potential problems such as damage to the incinerators and control of toxic emissions and hazardous constituents in the residual ash due to the variety of materials in mixed laboratory wastes, many incineration facihties did not wish to accept this category of materials, allhough some would accept properly segregated materials. In addition. 

Potential problems associated with the S SVG method include decomposition of the adsorbate as a result of intimate contact with adsorbent reactive sites. This effect has been observed for adsorbed HD and VX recently, and seems to be exacerbated by the presence of water vapor. Efforts to minimize this effect include use of low-ash adsorbents, operating at as low a temperature as possible, and avoiding the presence of water. The latter includes sample preparation methods to reduce water contamination and use of ultra-dry carrier streams since water vapor in the carrier... 

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