Progress in the determination of water in glasses and melt inclusions with Raman spectroscopy

摘要

Our understanding of the behavior of volatiles in silicate melts has been closely linked to the development of the experimental and analytical methods that have been applied to investigate them (Hunger et al. 1994). In this contribution, I show that the high spatial resolution and high accuracy of Raman spectroscopy make it an important microanalytical technique for quantifying water in natural and experimental glasses.rnUp to about 1999 microRaman spectroscopy had not yet been applied to the quantitative determination of water dissolved in silicate melts or glasses, but it had been used extensively in the study of fluid inclusions (e.g., Burke, 2001), the identification of daughter minerals in fluid and melt inclusions as well as in structural studies of volatile-containing glasses (see Ihinger et al. 1994). Recently, the determination of water in natural glasses using confocal microRaman spectroscopy has developed into an established, routine analytical method (Thomas, 2000 and 2002; Thomas et al. 2005, 2006; Chabiron et al. 2004; Zajacz et al. 2005; Behrens 2006; Di Muro et al. 2006). This technique can be used for accurate and rapid determination of the total water content of glasses with high precision ( < 10%) in a wide concentration range (i.e., from 0.1 to over 35 wt% (～50 mol% H_2O)). However, the lower detection limit is not explored yet. With some reservation (after clarification the physical meaning of the sub-bands in the 3550 cm~(-1) region: see Behrens et al. 2006), quantitative determinations of the speciation of water (H_2O_m/OH) (Chabiron et al., 2004; Di Muro et al. 2006) and of heavy water (D_2O_m/OD) (Thomas et al, 2006) are also possible.