Quantification of CO2 concentration in apatite
Quantification of CO2 concentration in apatite
复制标题
磷灰石中 CO2 浓度的定量
DOI：
--
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
F. Naab
中科院分区：
文献类型：
--
作者：
K. Clark;Youxue Zhang;F. Naab
摘要我们用核反应分析（NRA）得到的绝对浓度校正了测定磷灰石中CO2浓度的红外（IR）方法。使用偏振透射红外光谱法在双抛光磷灰石晶片上获得红外数据。由于CO2-3在磷灰石中的位置和取向不同，不同磷灰石样品的红外光谱复杂且形状不一致。因此，简单的峰高不用于表征磷灰石中的CO2浓度。总吸光度（Atotal）使用给定偏振光谱区域中的曲线下的积分面积导出。然后是Atot！II计算为AE//c + 2AE±c。校准已进行了两个波数区域，一个具有高灵敏度和其他适用于磷灰石与高CO2浓度。第一个校准是针对基本不对称的CO 32 −
m CO^{2-}_3$在1600-1300 cm-1的波数下拉伸，并且可以获得以百万分率计的CO2浓度为（0.0756 ± 0.0036）Atotal/d，其中d是以cm计的样品厚度。基本拉伸带是强的，因此对于测量磷灰石中的低CO2浓度敏感，低至百万分之一的水平。第二次校准是针对CO 32 − $
m CO^{2-}_3$谱带的波数为2650 -2350 cm-1，CO_2浓度的ppm为（9.3 ± 0.6）Atotal/d，其中d为样品厚度（cm）。这些谱带很弱，因此可用于测量磷灰石中的高CO2浓度，而无需制备超薄晶片。各向异性是显著的。AE//c和AE±c之间的差异可达到2.73倍。因此，为了获得高精度，最好使用偏振IR来确定磷灰石中的CO2浓度。对于粗略估计，可以通过估计Atotal = 3Aunpol来使用非偏振IR光谱，其中Aunpol是来自非偏振光谱的积分吸光度。
Abstract We have calibrated the infrared (IR) method for determining CO2 concentrations in apatite with absolute concentrations obtained through nuclear reaction analysis (NRA). IR data were obtained on double-polished apatite wafers using polarized transmission IR spectroscopy. Due to the various sites and orientations of CO2-3 in apatite, the IR spectra are complicated and do not have the same shape in different apatite samples. Hence, simple peak heights are not used to characterize CO2 concentrations in apatite. The total absorbance (Atotal) was derived using the integrated area under the curves in a given polarized spectral region. Then Atot!ll is calculated as AE//c + 2AE±c. The calibration has been carried out for two wavenumber regions, one with high sensitivity and the other applicable to apatite with high CO2 concentrations. The first calibration is for the fundamental asymmetric CO32− $
m CO^{2-}_3$ stretching at wavenumbers of 1600-1300 cm-1, and the CO2 concentration in parts per million can be obtained as (0.0756 ± 0.0036) Atotal/d where d is sample thickness in centimeters. The fundamental stretching bands are strong and hence sensitive for measuring low CO2 concentrations in apatite, down to parts per million level. The second calibration is for the CO32− $
m CO^{2-}_3$ bands at wavenumbers of2650-2350 cm-1, and the CO2 concentration in parts per million is (9.3 ± 0.6) Atotal/d where d is sample thickness in centimeters. These bands are weak and hence are useful for measuring high CO2 concentrations in apatite without preparation of super-thin wafers. The anisotropy is significant. The difference between AE//c and AE±c can reach a factor of 2.73. Hence, for high accuracy, it is best to use polarized IR to determine CO2 concentrations in apatite. For rough estimation, unpolarized IR spectra may be used by estimating Atotal = 3Aunpol, where Aunpol is the integrated absorbance from unpolarized spectra.
岩浆磷灰石的挥发物清单（F、Cl、Br、S、C）：一种综合分析方法
影响因子：
3.9
作者：
Wenzel;Whitehouse;Worgard;Stosnach
通讯作者：
Stosnach