| タイトル | Determination of the D and L isomers of some protein amino acids present in soils |
| 著者（英） | Cheng, C.-N.; Pollock, G. E.; Cronin, S. E. |
| 著者所属（英） | NASA Ames Research Center |
| 発行日 | 1977-01-01 |
| 言語 | eng |
| 内容記述 | The D and L isomers of some protein amino acids present in soils were measured by using a gas chromatographic technique. The results of two processing procedures were compared to determine the better method. Results of the comparison indicated that the determination of D and L percentages requires amino acid purification if one is to obtain accurate data. It was found that very significant amounts of D-alanine, D-aspartic acid, and D-glutamic acid were present in the contemporary soils studied. Valine, isoleucine, leucine, proline, and phenylalanine generally contained only a trace to very small amounts of the D isomer. It is probable that the D-amino acids from the alanine, aspartic, and glutamic acids are contributed to the soil primarily via microorganisms. The finding of very significant quantities of some D-amino acids (about 5-16%) in present-day soils may alert some investigators of geological sediments to a possible problem in using amino acid racemization as an age-dating technique. |
| NASA分類 | CHEMISTRY AND MATERIALS (GENERAL) |
| レポートNO | 77A22176 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/439213 |
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