Determination of the Content of Alkalis and Acids in Paper
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| Format: | Article |
| Language: | English Slovak |
| ISSN: | ISSN 0034-5806 |
| Online Access: | http://www.viks.sk/chk/res_3_4_99_126_136.doc |
| Abstract: | SUMMARIES. The content of acids and alkalis in paper should be determined by acid-base back-titration. However, during extraction of paper by NaOH or H2 SO4 , interaction with the cellulose takes place, which distort the subsequent back-titration. Therefore, when alkaline paper is extracted by acids, the subsequent titration should take place in the presence of the paper. After extraction of acidic paper with NaOH it is not possible to determine the acids by a subsequent back-titration. Therefore, the acidic paper should be extracted by a CaCO3 suspension. Then the surplus of CaCO3 is dissolved by H2 S04. Finally, the acids of paper are determined by back-titration of the H2 S04. CONCLUSION. For the determination of acid or alkali in paper acid-base back-titration was investigated. The titration should takes place in the presence of the paper. Otherwise, the measurement becomes inaccurate because of the interaction of acid with paper during extraction. In the case of determination of acids in the paper, the paper should be extracted by a CaC03 suspension. After dissolving of the surplus of CaCO3, by H2 SO4 , the acids contained in the paper are determined by back-titration of , the H2 SO4 . Thus, only those acids were determined which would be neutralized during a conservation treatment with CaCO3. In this respect, this method of determination of acids in paper is relevant to practice in paper deacidification.During the determination of acids in the paper, the second equivalent point represents the summary content of acids. By separate evaluation of the equivalent points 1 and 2, it should be possible to distinguish between weak and strong acids in paper. It must be clarified in further investigations whether it is possible to quantify strong and weak acids separately. Because the acidimetric determination of acids and alkalis is a destructive method of analysis, it can be used only for investigation of a test paper. Therefore, the aim for further investigation is to improve these methods to a micromethod, which needs only very small quantities of paper. In this way the acidimetric determination of acids and alkalis could become a quasi non-destructive analytical method. |
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| ISSN: | ISSN 0034-5806 |
