DETERMINATION OF IRON AND COPPER IN 18th AND 19th CENTURY BOOKS BY FLAMELESS ATOMIC ABSORPTION SPECTROSCOPY
Lucia C. Tang
4 SUMMARY AND CONCLUSIONS
Our study indicates that while biological organisms such as molds may be a factor in the formation of foxing spots, copper and iron also seem to play a prominent role. The iron content of foxing spots and clear papers in the books examined showed a significant difference. However, the copper content of these areas was not significantly different. On the other hand, in our handmade paper it was the copper content that varied significantly in these areas.
Some foxing spots were more deteriorated than others, but all were deteriorated in relation to the adjacent paper. The data presented show that in many papers iron in amounts over 500 ppm and copper in amounts over 90 ppm are associated with the foxed spots, as shown in Figures 3 and 4, and degraded areas. Since both iron and copper catalyze the oxidation of cellulose, these agents may be primarily or completely responsible for the damage. Other papers show foxing in the presence of small amounts of iron and copper, as shown in Figure 5, and in such cases foxing may well be produced by biological organisms alone.
Traditionally, these elements in paper have been analyzed by classical gravimetric and titrimetric analytical techniques, colorimetry, or flame atomic absorption. CRA (Carbon Rod Atomizer) offers a simple, rapid, and extremely sensitive method of determining metals in cellulosic materials directly on the solid sample. The very small solid samples utilized in this technique were useful in demonstrating the wide variation of metal concentrations in the cellulose matrix of a single blank page. CRA provides excellent information on the distribution of the elements throughout the sample and can help to elucidate the cause of foxing spots in library materials.
TABLE VII TITLES OF BOOKS AND VARIOUS PAPERS