MPI-DING玻璃标样与大洋中脊火山玻璃主量元素的均一性研究
0 引 言
原位微区分析技术的发展一直备受科学界的关注。一方面该技术使实验过程在一定程度上避免了繁琐耗时的湿法化学消解,实验方法更加简化;另一方面使传统宏观意义上岩石矿物的研究,逐渐转变为微观意义上的固体单矿物之间的研究。国内外常用的原位微区分析测试主要有电子探针微束分析(EPMA)、 二次离子质谱分析(SIMS)、 同步辐射X射线荧光微束分析(SR-XRF)、 粒子诱发X射线荧光分析(PIXE)和激光剥蚀电感耦合等离子体质谱分析(LA-ICP-MS)等[1]。电子探针技术目前常用于固体微区测定单矿物的主量元素,其定量分析的元素范围为Na—U,特别是对较重元素的测定具有优势,轻元素经合适的修正也可以得到精确的质量分数。
合适而可靠的标准物质(标样)是化学成分分析实验中获得精准数据的前提,其作用表现在提高定量分析精度和数据质量监控两方面。现代原位微区分析技术中,标样基本有4类: 人工合成的标准玻璃、具有天然成分的地质标准玻璃、人工合成的矿物和天然的矿物[2]。其中玻璃物质是最常用的一种标样,包括人工合成的玻璃和由天然岩石或土壤熔融而成的标准玻璃,相对于天然矿物,玻璃的成分相对均一,利用玻璃标样能很好地对实验室数据质量进行监控和评估。
目前实验室用于微区分析常用的人工合成的标准玻璃包括美国国家标准与技术局(NIST)合成的SRM610~617系列的标准玻璃、 美国地质调查局(USGS)合成的USGS系列标准玻璃和德国马普化学研究所合成的MPI-DING标准玻璃。 NIST系列玻璃主要反映微量元素成分, 主量元素只有SiO2、 Al2O3、 CaO和Na2O, 完全不同于任何天然岩石和矿物样品的成分变化特征[2-3]。 其中, 最常用的人工合成玻璃是NIST SRM610(微量元素含量主要集中在(400~500)×10-6)和NIST SRM612(微量元素含量主要集中在(30~40)×10-6), 成分含量比较固定, 虽然无法与天然岩石进行比较, 但是在仪器测试数据的准确度和精确性矫正方面具有很重要的意义。 USGS标准玻璃和MPI-DING玻璃标样是由天然岩石或者土壤粉末直接熔融而成, 其成分变化特征与天然岩石样品更加接近, 更能反映自然界岩石矿物成分的变化特征。 USGS标准玻璃(BCR-2G、 BHVO-2G和BIR-1G)成分相对单一, 均为玄武质岩石。 而德国马普化学研究所MPI-DING标准玻璃是一套从超基性到酸性岩的玻璃标样, 包括科马提岩(GOR128-G,GOR132-G)、橄榄岩(BM90/21-G)、玄武岩(KL2-G,ML3B-G)、 安山岩(StHs6/80-G)、 石英闪长岩(T1-G)及流纹岩(ATHO-G)[4], 更接近天然岩石成分, 所以利用该系列标样对微区原位测定数据质量的评价更加理想。 MPI-DING玻璃标样对于测试自然界岩石矿物样品的成分含量范围(wB,SiO2=46%~75.6%,MgO=0.1%~22.5%,Al2O3=10.8%~17.6%,FeO=3.3%~11%[5])更具有代表性,例如利用电子探针衡量主量元素测试数据的质量具有重要的意义。
国内外众多实验室对MPI-DING玻璃标样的主量、微量元素和同位素成分进行了全面的微区原位测试,给出了大量的参考数据和详细的样品说明[3-14]。通过测试,证明MPI-DING玻璃标样在不同实验室测得的成分比较一致,因此MPI-DING玻璃标样可用来监控不同实验室数据测试质量。不同实验室测定的MPI-DING玻璃标样的数据误差除了包括系统误差,作为标准样品还可能与其自身的均一性有关系。本文利用桂林理工大学EPMA对MPI-DING玻璃标样主量元素进行测定,与国内外其他实验室的测定数据进行对比,来衡量该实验室的数据质量;并对同一块MPI-DING玻璃标样的不同位置的测定数据进行对比,来研究其均一性;此外,还分析测试了天然火山玻璃(大洋中脊火山玻璃),以期揭示人工玻璃形成过程与天然玻璃形成的均一性差异。
1 样品及测试方法
1.1 实验仪器参数及工作条件
利用日本电子(JEOL)JXA-8230 电子探针分析仪来测定7块MPI-DING标样玻璃和东太平洋洋中脊火山玻璃的主量元素。该电子探针配有1道能谱仪、1道阴极发光探头以及4道波谱仪,4道波谱共配置8块晶体(TAP、 LiF、 PET、 LiFH、 PETH、 LDE2、 LDE5、 LDE6)。首先使用JEOL JEE-420系列真空喷镀仪镀一层碳,以保证样品表面导电,采用灰度对比的方法控制厚度。标准样品采用中国地质科学院矿产资源研究所负责制作的国家标准天然样品。分析数据采用ZAF法校正(原子序数校正、 吸收效应校正、 荧光效应校正)。元素主要为α测试线系,若具有重叠峰的元素则使用相应β线系校正,以及相应背景、峰位校正。具体的测试参数见表1。
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图5是各个标样多次测量结果与其平均值的相对百分比的折线图,可以看到Mg和Fe在基性和中性岩玻璃中多次测量的数据波动较小,数据稳定性较好;在酸性岩玻璃中则明显看出数据间的起伏略大,说明这两种元素在基性岩和中性岩中更均一,分配得更好。K元素在基性玻璃样品GOR132-G、GOR128-G中多次测量的数据波动较大,是因为其在这两个样品中的含量过低,测试精度不高。Ca元素在基性岩中多次测量稳定性也很好,数据偏差小。Al元素和Na元素多次测量的数据中没有明显的规律。
表1 电子探针测试参数
Table 1 EPMA instrumental parameters
电子探针JEOL JXA-8230加速电压/kV15 加速电流/nA20 束斑直径/μm5 元素峰值测试时间/s20; 10(Na、 K、 Ca) 背景值测试时间/s10; 5(Na 、K、 Ca) 测试元素检出限/10-6Na 54; Mg 56;Al 56;Si 32;P 68;S 34;K 64;Ca 37;Ti 43;V 53;Cr 58;Mn 60;Fe 50;Co 58;Ni 60;Cu 95;Zn 78
1.2 标样及玻璃样品
选取MPI-DING玻璃和洋中脊火山玻璃进行了电子探针原位微区主量元素的分析。由德国马普研究所Jochum 博士提供的MPI-DING玻璃标准参考物质包括玄武岩(KL2-G, ML3B-G)、 安山岩(StHs6/80-G)、 科马提岩(GOR128-G, GOR132-G)、 流纹岩(ATHO-G)及石英闪长岩(T1-G)[4]。 SiO2在GOR132-G、 GOR128-G、 KL2-G、 ML3B-G、 T1-G、 StHs6/80-G和ATHO-G中含量分别为45.5%、 46.1%、 50.3%、 51.4%、 58.6%、 63.7%和75.6%。火山玻璃样品采自太平洋洋中脊区域(图1),由深海取样器从轴部裂谷的地表、轴脊的峰顶和转换断层交叉处轴脊的颚式延长部分取得,另外,在太平洋板块的火山链和洋脊周围采集了较新的喷发熔岩玻璃,火山链位于EPR最南端轴脊和Heezen转换断层之间的“内侧角”,火山熔岩沿着横切转换断层伸展断裂部分喷出。
实验室对玻璃样品GOR132-G、 GOR128-G、 KL2-G、 ML3B-G、 T1-G、 StHs6/80-G和ATHO-G分别进行了主量元素的测试, 沿直线在不同位置对每个样品测定20次左右, 所测主量元素包括SiO2、 TiO2、Al2O3、FeO、MgO、CaO、Na2O和K2O,测量结果见表2。
图1 全球板块构造单元纲要图及采样区域(据文献[15])Fig.1 Global plate tectonic unit outline diagram and sampling areaa区对应样品号为RNDB;b区对应的样品号为PPTU;c区对应样品号为EPR
2 结 果
2.1 MPI-DING玻璃标样测量结果
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2.2 东太平洋火山玻璃测量数据
本次试验样品的8块洋中脊火山玻璃(RNDB15-D22-1A、 RNDB15-D63-4A、 EPR1-3、 EPR3-2、 PPTU19-3、 PPTU33-1、 RNDB15-5-8、 RNDB15-20-1A)主要由美国加州大学圣迭戈分校Scripps海洋研究所提供。将火山玻璃切取小块,用透明环氧树脂固定制靶,喷碳后利用电子探针测定主量元素数据,每个样品沿一条直线测定20个点左右,结果见表3。
表2 MPI-DING玻璃主量元素测定结果
Table 2 Determination results of major elements for MPI-DING glass wB/%
样品号SiO2TiO2Al2O3FeOMgOCaONa2OK2OTotal49.823.5314.368.767.8611.912.310.4799.7048.823.4314.848.987.6612.072.190.4098.8050.473.3414.379.167.8112.062.210.44100.4149.752.5514.718.807.6611.982.280.5298.8249.452.5014.638.997.6711.832.160.5098.30KL2-G49.762.5614.619.247.6011.791.950.4598.3949.582.5214.438.687.8011.942.190.4898.2050.142.6714.668.697.7412.172.190.5499.7249.982.7214.618.787.7412.132.200.4299.1849.882.5314.358.847.8311.942.280.4798.84
续表2
样品号SiO2TiO2Al2O3FeOMgOCaONa2OK2OTotal50.742.6314.438.607.8012.092.070.4999.4564.880.6317.213.751.884.914.041.1899.12364.270.5817.103.741.884.994.151.1798.09464.880.6317.213.751.884.914.041.1899.12364.320.9717.583.622.075.853.991.35100.1863.540.8917.543.622.095.743.861.3098.98StHs6/80-G62.880.9317.293.802.105.914.011.2898.4762.190.9817.313.842.075.874.041.3898.1162.521.0816.783.702.065.834.191.2997.9262.660.9016.973.662.135.703.831.2897.6963.690.9817.813.932.115.914.001.29100.0463.080.9817.353.882.035.904.041.4099.1357.450.9216.585.523.867.682.882.0097.3559.770.9516.595.403.817.542.942.0299.3958.600.8916.625.353.927.593.052.0498.6060.141.0516.865.283.917.812.892.01100.3759.310.9016.665.383.927.623.061.9099.16T1-G57.281.0216.525.283.897.572.901.9296.6957.960.9416.235.373.637.672.732.0397.0358.490.9116.625.183.857.713.022.0498.2758.571.0216.755.273.987.663.092.0798.8058.250.9016.855.383.837.612.962.1098.1757.011.0216.795.333.947.673.061.8997.1845.860.339.868.4327.166.750.610.0499.9645.590.389.788.2327.506.880.640.0599.7945.130.399.698.2427.106.810.590.0798.7344.530.369.728.3926.666.750.690.0698.1646.060.329.668.2627.266.780.660.0199.90GOR128-G45.220.369.688.1527.646.690.570.0299.1445.260.319.888.1927.446.730.510.0299.1745.950.399.778.0127.596.780.610.0799.8345.710.409.877.9127.496.820.620.0599.7645.700.349.558.2127.126.760.600.0599.0345.120.339.658.2627.236.770.540.0498.7045.880.399.598.2327.166.870.500.0599.2345.550.319.838.6127.126.860.590.0499.8845.220.419.518.4327.066.730.560.0898.9074.940.3511.912.980.111.882.652.7698.0473.520.3612.162.980.091.822.532.7396.4674.310.2212.102.930.091.882.442.7296.8672.960.3111.962.960.111.882.612.7395.8372.740.3511.942.990.071.942.562.8395.7273.080.3111.812.930.101.832.472.8195.66ATHO-G74.500.2912.063.030.101.832.492.7097.4177.080.3511.812.770.101.822.542.8499.5676.440.3411.962.840.121.862.462.6498.8974.290.2811.992.980.101.932.452.7297.0174.470.3111.572.930.111.762.212.7396.2774.450.3211.832.800.101.862.442.7196.7078.200.4311.922.840.111.952.052.89100.64
续表2
样品号SiO2TiO2Al2O3FeOMgOCaONa2OK2OTotal51.892.8413.688.857.1311.382.330.4299.1350.582.8713.789.197.2011.442.320.3898.3250.632.9313.969.267.1111.512.230.3998.6249.972.7013.739.017.2011.422.410.3897.3052.082.7513.838.917.2111.482.290.3899.56ML3B-G51.292.7113.859.027.1511.612.440.3698.8750.912.8613.679.017.1811.492.280.4298.2450.932.5813.439.187.1111.792.320.4198.6850.952.7913.979.087.1211.692.380.3998.8751.102.8114.009.227.2211.542.320.3999.2650.672.9213.709.317.1211.332.370.3198.1344.430.4810.699.0023.939.140.770.0399.1944.620.4110.868.4723.979.150.830.0499.2745.070.4010.718.9223.699.260.850.0399.5643.810.3811.088.7523.949.060.810.0598.7644.210.3810.768.5123.809.220.800.0598.5343.980.3410.878.4923.479.340.770.0698.32GDR132-G43.910.3911.028.6123.839.350.930.0698.8343.990.4910.738.5023.839.240.800.0698.6043.820.4711.128.7423.899.460.760.0599.4343.760.4211.148.8023.799.370.920.0499.0544.300.4510.858.9623.819.400.890.0599.5244.480.4410.978.6723.759.070.810.0499.0044.180.4010.798.4123.699.060.870.0498.49
表3 东太平洋火山玻璃主量元素测定结果
Table 3 Determination results of major elements for east Pacific volcanic glass wB/%
样品号SiO2TiO2Al2O3FeOMgOCaONa2OK2OP2O5TotalRNDB15-D22-1A-148.001.5317.799.287.7512.022.870.300.1897.23RNDB15-D22-1A-246.971.6518.889.078.0511.902.730.300.2198.46RNDB15-D22-1A-347.251.3817.799.178.8812.052.830.350.1698.93RNDB15-D22-1A-447.651.6617.549.537.8612.272.840.270.1897.93RNDB15-D22-1A-547.511.6217.719.218.0212.302.870.350.1597.67RNDB15-D22-1A-646.971.5418.099.138.5312.062.940.280.1898.70RNDB15-D22-1A-747.971.4217.989.227.6412.272.810.340.1798.11RNDB15-D22-1A-847.361.5017.549.248.7712.162.770.290.1898.73RNDB15-D22-1A-947.331.3717.629.448.5512.222.750.320.1698.97RNDB15-D22-1A-1046.801.4918.339.218.6011.992.790.290.2099.15RNDB15-D22-1A-1147.411.3917.549.468.5512.222.770.310.1898.15RNDB15-D22-1A-1247.341.5018.689.288.0611.762.720.330.1797.39RNDB15-D22-1A-1347.021.6317.989.408.1512.162.890.320.1998.53RNDB15-D22-1A-1447.561.2917.649.478.4212.252.710.300.1698.09RNDB15-D22-1A-1547.461.6517.649.497.9312.442.750.340.1697.06RNDB15-D22-1A-1646.871.4017.889.348.9112.102.830.290.2098.49RNDB15-D22-1A-1747.081.4117.849.528.0412.343.080.300.1897.20RNDB15-D22-1A-1847.001.4517.749.538.5812.162.940.260.1597.63RNDB15-D22-1A-1947.121.3818.159.448.1312.152.890.360.1997.98Avg47.301.4917.919.348.2812.152.830.310.18SD0.340.110.380.150.390.160.090.030.02RSD/%0.737.642.101.584.661.333.279.269.65
续表3
样品号SiO2TiO2Al2O3FeOMgOCaONa2OK2OP2O5TotalRNDB15-D63-4A-150.731.8715.0611.846.0910.403.530.150.12100.28RNDB15-D63-4A-250.541.5314.389.798.0812.382.780.110.13101.77RNDB15-D63-4A-351.351.5715.0310.876.2311.073.360.100.15100.28RNDB15-D63-4A-451.171.6214.749.567.3912.272.890.100.1299.85RNDB15-D63-4A-550.231.7014.788.249.0612.632.920.060.14101.63RNDB15-D63-4A-651.891.4715.209.536.7911.513.220.060.1499.84RNDB15-D63-4A-751.791.5414.3710.746.7211.552.880.110.1399.78RNDB15-D63-4A-850.261.6314.3710.578.2511.552.980.030.16101.08RNDB15-D63-4A-951.211.7314.0011.537.0611.332.720.150.1397.33RNDB15-D63-4A-1051.261.5614.229.967.4112.232.940.090.16100.14RNDB15-D63-4A-1151.581.4114.488.677.8512.872.830.050.12100.43RNDB15-D63-4A-1250.811.5814.3811.527.1811.072.980.020.17100.92RNDB15-D63-4A-1351.621.2714.5812.165.8210.623.410.100.16100.76RNDB15-D63-4A-1451.051.7814.618.358.3412.762.690.040.09100.41RNDB15-D63-4A-1551.701.6213.858.328.3012.962.820.050.1599.61RNDB15-D63-4A-1650.621.9314.278.738.2412.992.940.060.10100.23RNDB15-D63-4A-1750.931.5814.768.868.2312.402.920.070.14100.75RNDB15-D63-4A-1851.561.7113.9610.346.9611.972.900.090.15100.79RNDB15-D63-4A-1949.901.8113.917.3810.4714.042.150.040.12102.10RNDB15-D63-4A-2049.530.975.426.5416.6919.770.360.010.05100.87Avg50.991.5914.029.688.0612.422.810.070.13SD0.660.212.061.542.311.950.650.040.03RSD/%1.2913.3514.7015.9028.6215.7222.9851.7120.74EPR1-3-175.970.0713.141.970.180.713.334.530.03102.68EPR1-3-276.030.2812.812.120.180.703.164.560.05101.44EPR1-3-375.430.1913.372.050.100.693.594.550.00102.35EPR1-3-478.080.1312.022.030.000.692.444.460.0399.53EPR1-3-575.630.2313.561.770.000.613.394.680.01100.34EPR1-3-676.190.2012.782.130.010.783.034.710.0199.15EPR1-3-775.350.1413.322.010.110.613.894.370.03102.08EPR1-3-874.190.0313.942.010.160.704.334.570.01100.32EPR1-3-975.500.1613.352.080.080.693.584.490.00101.35EPR1-3-1073.790.3014.082.090.200.724.314.370.02100.79EPR1-3-1175.620.0813.122.020.160.713.774.440.00101.11EPR1-3-1275.480.3313.211.960.140.753.684.320.00101.04EPR1-3-1374.990.1313.682.070.130.713.834.330.0198.50EPR1-3-1474.470.1314.052.020.000.724.084.480.00101.83EPR1-3-1575.800.1213.331.980.030.743.464.360.03101.85EPR1-3-1675.010.2113.691.990.100.663.624.590.02101.85EPR1-3-1775.520.1913.191.880.190.643.924.390.05102.62EPR1-3-1875.160.2113.511.900.150.603.874.500.00102.32EPR1-3-1975.260.1613.232.070.120.773.754.460.04102.50EPR1-3-2075.540.3013.192.020.150.673.554.470.01101.97EPR1-3-2175.450.3013.331.960.000.633.764.360.01101.15EPR1-3-2275.540.1913.281.800.130.713.664.620.00100.91EPR1-3-2377.320.2412.321.480.010.433.594.510.03100.70EPR1-3-2473.920.2014.261.970.070.684.254.530.0099.71EPR1-3-2575.000.1613.451.940.210.713.924.520.0199.51EPR1-3-2675.340.1313.341.910.030.653.954.340.03100.14EPR1-3-2776.200.1313.091.890.110.503.514.480.00100.79EPR1-3-2874.190.1513.792.050.130.724.034.740.0198.50
续表3
样品号SiO2TiO2Al2O3FeOMgOCaONa2OK2OP2O5TotalAvg75.430.1813.341.970.100.673.694.490.02SD0.910.070.490.130.070.080.400.110.01RSD/%1.2140.963.656.6266.3911.1310.792.5396.34EPR3-2-175.080.2713.242.290.040.733.674.610.0197.02EPR3-2-274.580.1613.642.030.030.783.974.680.0197.16EPR3-2-373.250.2314.082.230.230.694.334.920.0197.48EPR3-2-474.040.2513.852.320.150.903.904.510.0197.54EPR3-2-575.540.1713.301.860.000.783.714.530.0398.31EPR3-2-674.340.1613.722.210.100.833.904.580.0397.88EPR3-2-775.010.1713.412.090.090.743.744.580.0298.54EPR3-2-875.720.0213.431.840.010.583.644.660.0197.09EPR3-2-974.900.1913.631.940.120.693.764.600.0497.67EPR3-2-1074.170.2313.632.250.060.833.874.670.0298.00EPR3-2-1174.920.2813.202.340.100.643.814.520.0098.44EPR3-2-1274.730.1613.502.170.060.673.904.680.0397.21EPR3-2-1373.380.0813.842.630.261.024.054.610.0197.74EPR3-2-1474.940.2713.821.820.160.723.644.530.0298.15EPR3-2-1574.230.2314.142.050.000.723.844.530.0297.68EPR3-2-1674.850.1913.601.970.150.783.764.630.0197.37EPR3-2-1774.890.2213.432.140.100.773.654.700.0297.21Avg74.620.1913.622.130.100.763.834.620.02SD0.660.070.270.210.080.100.180.100.01RSD/%0.8935.012.009.9477.5413.404.592.1567.29PPTU19-3-158.080.4520.574.471.649.045.420.110.0499.58PPTU19-3-250.741.8114.4613.485.5310.393.150.090.1497.94PPTU19-3-350.062.0014.5213.615.8210.233.270.110.1598.33PPTU19-3-451.511.7014.6813.955.5310.651.490.130.1697.49PPTU19-3-551.892.0914.5713.765.2710.311.430.120.2097.55PPTU19-3-650.421.8714.1513.305.9710.613.070.170.2197.97PPTU19-3-750.801.7714.4113.305.4410.453.150.150.2098.41PPTU19-3-850.642.0914.3013.305.7010.313.160.160.1797.96PPTU19-3-950.491.7614.4413.365.9810.343.160.070.1698.38PPTU19-3-1050.762.1014.2213.275.7810.293.020.090.2299.23PPTU19-3-1151.122.0014.4113.315.2910.313.120.120.1598.15PPTU19-3-1250.731.8614.2513.405.6410.483.110.110.1899.32PPTU19-3-1351.251.9914.4513.165.1510.483.060.140.1598.37PPTU19-3-1451.151.7814.4313.175.6210.362.980.140.1697.99PPTU19-3-1550.441.9514.5313.345.8410.223.090.120.1798.64PPTU19-3-1651.111.9814.3313.474.8910.433.220.130.1798.14PPTU19-3-1750.211.9914.5613.345.6910.473.230.160.1498.78PPTU19-3-1851.031.8514.4113.225.5110.333.120.100.1898.46PPTU19-3-1951.282.0914.2213.385.2510.472.850.100.1598.56PPTU19-3-2050.572.0314.2713.285.8210.433.130.070.1799.43PPTU19-3-2150.491.7714.7413.125.8310.393.120.140.2098.80Avg51.181.8514.7112.955.3910.333.060.120.16SD1.640.341.351.950.910.320.740.030.04RSD/%3.2118.599.1815.0816.803.0624.1223.5622.84PPTU33-1-147.790.8517.178.589.9513.102.360.020.0697.70PPTU33-1-248.390.8117.278.549.8612.852.100.000.0697.24PPTU33-1-347.761.1617.148.5410.0412.832.190.070.0598.39PPTU33-1-447.890.6517.268.4810.5112.662.200.060.0598.51
续表3
样品号SiO2TiO2Al2O3FeOMgOCaONa2OK2OP2O5TotalPPTU33-1-547.550.9417.268.5610.2612.822.140.170.0597.05PPTU33-1-648.460.7517.078.449.9812.842.100.010.0697.38Avg47.970.8617.198.5210.1012.852.180.060.05SD0.370.180.080.050.240.140.100.060.01RSD/%0.7720.510.480.612.401.084.43107.6614.18RNDB15-5-8-149.500.9815.749.468.9812.822.140.070.0798.63RNDB15-5-8-250.140.6916.419.298.7012.481.900.040.0799.79RNDB15-5-8-347.630.7119.918.688.5012.251.860.040.0999.94RNDB15-5-8-448.210.8419.268.778.3812.421.650.030.0599.72RNDB15-5-8-550.530.8215.959.298.3912.861.800.020.0799.33RNDB15-5-8-650.090.7616.419.408.2812.672.040.030.0798.44RNDB15-5-8-748.890.9818.878.578.3612.161.770.090.09100.29RNDB15-5-8-851.090.6715.469.128.8612.572.030.020.0699.57RNDB15-5-8-950.181.0217.069.267.6912.671.820.070.0497.36RNDB15-5-8-1048.970.9515.909.559.1413.022.140.030.0997.58RNDB15-5-8-1148.610.8918.688.878.0812.731.850.070.0597.42RNDB15-5-8-1250.461.0316.888.948.1512.641.710.040.0799.70RNDB15-5-8-1350.170.9416.599.098.5612.581.780.040.0699.32RNDB15-5-8-1449.040.8418.118.928.2012.552.090.030.0498.74RNDB15-5-8-1547.710.9020.228.668.5911.761.790.050.05101.08RNDB15-5-8-1649.771.0216.839.158.4512.451.960.050.0899.57RNDB15-5-8-1745.690.6824.648.147.4511.391.760.050.0798.52RNDB15-5-8-1841.480.6331.907.167.0410.081.490.020.06100.46RNDB15-5-8-1950.860.8715.629.377.9112.952.050.080.1097.01RNDB15-5-8-2049.400.7019.338.757.8312.071.680.040.0699.17RNDB15-5-8-2150.220.7316.649.128.5712.661.780.070.0798.96RNDB15-5-8-2249.510.8416.379.178.7912.891.950.080.0798.01RNDB15-5-8-2347.530.8219.648.629.0011.962.080.060.0699.74RNDB15-5-8-2450.960.7115.709.398.1612.891.840.090.0497.08RNDB15-5-8-2558.560.6612.778.056.8111.371.450.040.08102.80RNDB15-5-8-2649.760.7716.599.178.8412.541.960.060.05100.25RNDB15-5-8-2748.520.8419.428.828.0412.251.850.070.0798.93Avg49.390.8318.038.928.2912.361.860.050.06SD2.680.123.570.520.570.630.180.020.02RSD/%5.4214.9919.785.786.875.099.6041.2126.01RNDB15-20-1A-148.450.8119.508.088.3212.531.800.150.0699.11RNDB15-20-1A-249.610.7317.817.898.6112.831.930.190.0498.96RNDB15-20-1A-349.170.7718.008.108.4812.972.050.240.1098.74RNDB15-20-1A-449.160.4917.538.089.2513.031.920.160.0999.36RNDB15-20-1A-549.020.9217.408.109.1013.031.930.170.1199.55RNDB15-20-1A-649.950.6417.338.118.4712.912.060.200.0898.94RNDB15-20-1A-749.540.7917.488.158.7912.682.000.200.0999.54RNDB15-20-1A-847.670.7821.437.538.1512.161.840.160.0899.45RNDB15-20-1A-948.650.7619.337.938.3212.612.040.170.0899.65RNDB15-20-1A-1048.980.8417.768.079.0412.642.090.170.1199.55RNDB15-20-1A-1148.770.9319.947.618.3012.231.800.180.0897.68RNDB15-20-1A-1249.880.8117.268.138.3013.112.040.160.1197.82RNDB15-20-1A-1348.630.8618.667.788.5712.912.120.140.0999.16RNDB15-20-1A-1449.190.7317.418.119.0713.072.000.140.0698.44RNDB15-20-1A-1549.450.7417.288.128.8512.942.070.190.0999.63RNDB15-20-1A-1649.560.8117.087.939.3912.702.140.130.0698.73
续表3
样品号SiO2TiO2Al2O3FeOMgOCaONa2OK2OP2O5TotalRNDB15-20-1A-1749.940.8716.897.988.7613.062.090.150.0898.65RNDB15-20-1A-1849.530.7616.768.069.5013.041.960.160.1099.33RNDB15-20-1A-1949.480.9317.278.079.1812.851.900.170.0599.40RNDB15-20-1A-2048.320.7419.297.808.7412.731.930.190.0799.33RNDB15-20-1A-2148.940.6918.238.089.1312.401.970.140.0899.38RNDB15-20-1A-2249.960.7617.138.088.5513.132.020.180.0799.11RNDB15-20-1A-2347.690.8621.027.608.2912.132.010.140.0699.30RNDB15-20-1A-2449.230.9817.948.058.5712.911.950.150.0798.17RNDB15-20-1A-2549.490.7717.367.939.1912.782.110.170.0899.98RNDB15-20-1A-2649.050.6118.308.058.6812.832.080.170.0497.76RNDB15-20-1A-2749.840.8217.237.968.5313.002.050.210.0599.43RNDB15-20-1A-2849.710.5717.718.058.4113.022.060.200.0998.23RNDB15-20-1A-2949.150.7018.037.858.9212.961.920.200.1099.68Avg49.170.7818.087.978.7412.802.000.170.08SD0.610.111.190.170.370.280.090.030.02RSD/%1.2514.006.582.114.262.194.6114.5725.15
Avg—平均值; SD—标准偏差; RSD—相对标准偏差,%。
3 讨 论
3.1 MPI-DING玻璃标样测量数据的准确度分析
将本次7个MPI-DING玻璃标样的主量元素测定结果与Jochum等[4]提供的推荐值(PreferredValue)相比较(表4), 得出本次测试平均值与推荐值的相对误差散点图(图2)。从数据结果看,测试平均值与2006年Jochum MPI-DING推荐值的偏差基本在10%以内。FeO测定值整体低于推荐值,且相对误差均大于10%。TiO2的测定值高于推荐值,基本都在10%误差范围以外,可能是由于绝大部分标准样品中Ti含量不足1%造成的。Na2O只有StHs6/80-G和ATHO-G的测试结果偏低,与推荐值的相对误差大于10%。K2O中GOR132-G和GOR128-G的测量值相对误差较大,这两个样品的K含量较低,可能是导致其多次测量的相对偏差上下浮动较大的原因。其余元素的测量值相对误差均在10%的范围内。总体上,本次测定的7个MPI-DING玻璃标准参考物质的测定平均值和推荐值十分吻合。
图3为本次所测得的7个MPI-DING标样主量元素数据和Jochum的推荐值的线性关系。 可知, 桂林理工大学电子探针室所测的7个标准样品的主量元素与其推荐值均为正相关关系,所有的点均落在直线上或紧贴直线,斜率K值约等于1,证明此次测量数据与推荐值基本一致。 判定系数R2均非常接近于1,说明数据的拟合程度几乎是完全的,趋势线可靠度高,测定值与Jochum提供的推荐值相关性很高。
图2 MPI-DING主量元素测定值推荐值[4]的相对误差Fig.2 Relative error of major elements of MPI-DING compared with preferred values
3.2 MPI-DING玻璃标样测量数据的精密度分析
3.3.2 天然火山玻璃样品均一性 为了进一步研究天然火山玻璃的均一性,采集数据时,选取玻璃薄片的一个剖面进行线性测试,测得主量元素,可用其标准偏差来说明总体的均一性,同时也可以看出线性测试中不同位置数据的变化。通过对比在东太平洋大洋中脊天然形成的火山玻璃和人工合成的玻璃,可以说明在自然界岩浆作用下形成的玻璃和实验室环境下合成的玻璃元素分配与均一程度的差异。
图6为8个火山玻璃样品的主量元素标准偏差图, 大部分主量元素的标准偏差值都在1以内, 说明多次平行测量的数据与平均值偏离的程度比较低, 数据之间彼此的符合程度较高。 总体上主量元素标准偏差值离散程度低, 比较集中, 多次平行测量数据之间的符合程度较高, 说明自然界天然形成的火山玻璃样品相对均一。 而Al、Si和Fe元素的标准偏差值上下浮动范围较大一些, 部分偏差值在1以外, 离散程度略高, 多次平行测定数据波动范围较大, 精密度略低。其中RNDB15-D63-4A、 RNDB15-5-8两个样品的主量元素标准偏差相比其他样品略有偏高, 数据间符合程度略低。
表4 本次测定结果与推荐值比较(MPI-DING玻璃)
Table 4 Comparison of the results between preferred values and this paper(MPI-DING glass) wB/%
样品号成分EPMA(GUT)AvgSDRSD/%RE/%MICRO T.均值Preferred Value均值SiO249.860.511.020.8850.350.3TiO22.820.4014.379.992.532.56Al2O314.550.171.139.3613.313.3KL2-GFeO8.870.202.2917.1510.710.7MgO7.740.081.095.487.347.34CaO11.990.121.0210.0210.910.9Na2O2.190.104.607.012.382.35K2O0.470.048.531.980.480.48SiO263.270.750.010.2563.663.7TiO20.960.050.0624.170.680.7Al2O317.440.350.022.8717.817.8StHs6/80-GFeO3.720.120.0314.104.374.37MgO2.100.040.022.911.961.97CaO5.860.100.025.915.325.28Na2O3.600.940.269.504.384.44K2O1.310.050.030.701.31.29SiO258.441.000.020.2758.658.6TiO20.960.060.0625.860.750.76Al2O316.640.180.012.6817.117.1T1-GFeO5.340.090.0217.096.426.44MgO3.870.090.023.173.733.75CaO7.650.070.017.727.097.1Na2O2.960.110.045.343.133.13K2O2.000.070.032.111.991.96SiO245.480.420.011.3445.946.1TiO20.360.040.1023.560.280.29Al2O39.720.120.011.949.99.91GOR128-GFeO8.250.180.0215.889.829.81MgO27.250.260.014.8125.926CaO6.780.060.018.726.236.24Na2O0.590.060.093.730.590.57K2O0.050.020.4516.510.040.04SiO274.541.770.021.4075.675.6TiO20.330.050.1527.930.2410.255Al2O311.920.150.012.2712.212.2ATHO-GFeO2.920.080.0310.683.323.27MgO0.100.010.121.190.0980.103CaO1.860.050.039.611.691.7Na2O2.450.160.0734.573.533.75K2O2.750.070.024.312.622.64SiO251.000.600.010.7851.551.4TiO22.800.110.0431.302.042.13Al2O313.780.170.011.3313.613.6ML3B-GFeO9.100.150.0216.5510.910.9MgO7.160.040.018.656.596.59CaO11.520.140.019.6810.510.5Na2O2.330.060.032.732.422.4K2O0.380.030.071.710.390.39
续表4
样品号成分EPMA(GUT)AvgSDRSD/%RE/%MICRO T.均值Preferred Value均值SiO244.200.380.012.8645.445.5TiO20.420.040.1135.280.30.31Al2O310.890.160.010.991111GOR132-GFeO8.680.200.0214.0610.210.1MgO23.800.130.016.2522.322.4CaO9.240.140.019.368.488.45Na2O0.830.060.070.060.850.83K2O0.050.010.2349.580.0310.031
注:EPMA(GUT)—本次实验的电子探针结果; Avg—平均值;SD—标准偏差;RSD—相对标准偏差,%;RE—本次实验测试值相对于推荐值的相对误差,%,推荐值据Jochum等[4];MICROT均值:为EPMA、SIMS、LIMS、 SR-XRF和PIXE测试值的均值,数据据Jochum等[4]; Preferred Value均值据Jochum等[4]。
图3 本次试验主量元素测定值与推荐值的线性关系Fig.3 Linear relationship of major elements between measured values and preferred valuesAvg(GUT)为本次利用桂林理工大学电子探针测定的8个主量元素测定平均值; 纵坐标JPV为Jochum等[4]推荐值
不同元素在不同类型的天然火山玻璃中分配的均一度不同,但大部分元素在中基性岩中均一性要更好,元素分配更均匀一些,可能是因为中基性岩中Si含量低,粘度小,流动性好,所以元素更容易均匀分配,数据间的相对偏差就小,均一性更好。
1.2 研究方法 治疗组采用雾化吸入3%高渗盐水2ml+硫酸特布他林雾化液2.5mg,对照组采用雾化吸入生理盐水2ml+硫酸特布他林雾化液2.5mg,每8h 1次,直至出院。此外,两组患儿均接受常规治疗,如抗感染、化痰、吸痰,必要时予给氧、补液等。
他呼呼喘着粗气,从地上爬起来,看到不远处的下方,一队人正举着灯球火把、亮子油松,呼喝着朝这边跑,却是闻声赶来的族人。
3.3 均一性
图4 测定结果的标准偏差(SD)和相对标准偏差(RSD)Fig.4 Standard deviation and relative standard deviation of the measurement results
3.3.1 MPI-DING玻璃标样均一性 本次所测的7个MPI-DING玻璃标样按照岩性从基性酸性排布为GOR132-G、GOR128-G、KL2-G、ML3B-G、T1-G、StHs6/80-G、ATHO-G,其中SiO2含量分别为45.4%、46.1%、50.3%、51.4%、58.6%、63.7%、75.6%。MPI-DING玻璃标样主要用于实验室微区分析,所以标样是否均一,将直接影响到实验数据质量。如果玻璃标样的均一性非常好,同一玻璃标样内,或两块同种玻璃标样间在任何位置的多次平行测量的差距应该非常小,每次测量所得的数据与多次测量的平均值相比,波动小,离散程度低。
年轻人正确的消费心理是其成长、进步的重要因素。无论是我们的民族美德,还是我国的社会发展水平等,都要求其形成正确的消费心理。大体上看,主要有以下要求:1.要树立生态、绿色的消费理念,尤其是在日常消费的过程中,更要积极坚持实行这些理念。从经济影响上看,只有从心理认同上升到具体行为上,这才算真正意义上的做到了绿色经济的相关要求。
综上,不同的主量元素在中基性岩中的多次测量值与平均值的离散程度各有差异,不同元素在不同的岩性中均一程度也不尽相同。其中RNDB15-D63-4A、RNDB15-5-8两个样品的主量元素标准偏差值相比其他样品略偏高, 数据间的符合程度略低。
图5 各标样主量元素中多次测定值与其平均值的相对百分比折线图Fig.5 Relation ration of the mean value to the measured value of major elements in each standard samples
图4是本次测定结果的标准偏差图和相对标准偏差图,其中SiO2的标准偏差值较大,其多次测量数据的SD均在0.25的范围之外,除了样品ATHO-G的SD为1.77,其余样品的SD均小于1,在可接受的范围内。同时可以看出样品越偏酸性,标准偏差越大,很可能是样品的不均一造成的。其他绝大部分的元素的标准偏差都在0.25以内,且SD值非常小,数据精密度高。
你们应注意坚持英文的表达方式,而且为了防止将来产生任何疑问,关于正确解释条约可能引起的所有问题必须以英文本为准。
图6 火山玻璃样品主量元素标准偏差Fig.6 Standard deviation diagram of major elements of the volcanic glass
RSD图中几乎所有元素的相对标准偏差值都在小于5%区域内,除了样品KL2-G中的Ti元素和K元素相对标准偏差值大于5%,离散程度略大,其他主量元素均比较集中,分散度低,大部分的主量元素均显示了与推荐值较高的符合程度。因此本次测定值的精密度高,多次平行测定结果之间的符合程度高。
3.3.3 人工玻璃与天然火山岩玻璃均一性对比 将天然火山玻璃与标样玻璃的测定结果进行对比,可以进一步了解人工合成玻璃与天然火山玻璃均一性的差别。这对说明自然界天然形成的火山玻璃结晶过程元素能否均一分布也有意义,同时可以对桂林理工大学电子探针实验室数据的精确度和准确度进行监控,检验实验室是否达到进行科学研究的标准。
图7、8是太平洋火山岩玻璃和MPI-DING玻璃标样的相似岩性样品中主量元素多次测量折线图。本次共选取了较有代表性的两组酸碱度相近的样品数据进行对比:一组是PPTU19-3和ML3B-G(图7),这两个样品中SiO2含量分别为51.06%和51.4%;另一组是EPR1-3和ATHO-G(图8),两个样品的SiO2含量分别为75.43%和75.6%。
可以明显地看出,Ca、K、Ti、Fe 4种元素在这两组对比的数据中均表现出较好的稳定性,数据波动小,彼此符合程度较高,说明这4种元素在岩浆中分配行为是均匀的,其他波动大的元素分配行为不均匀, 这可能是元素自身的性质决定的。相比较之下,人工合成玻璃标样的数据更平稳,偏差小, 均一度更高一些。 除此之外, 天然火山玻璃中其他的主量元素多次测量数据起伏较大,而其相对应的合成玻璃的主量元素数据则依然偏差小, 数据间符合程度高。 由此可以看出,天然火山玻璃中,有部分元素表现出比较均一的性质,但是总的来说人工合成玻璃的均一程度更高,作为标准样品用途更广,对于在实验中监控数据提高精度的作用更大。
图7 天然火山岩玻璃PPTU19-3与人工玻璃ML3B-G主量元素多次测量折线图Fig.7 Major elements measurements of natural volcanic glass PPTU19-3 and synthetic glass ML3B-G
图8 天然火山岩玻璃EPR1-3与人工玻璃ATHO-G主量元素多次测量折线图Fig.8 Major elements measurements of natural volcanic glass EPR1-3 and synthetic glass ATHO-G
4 结 论
(1)通过对比本次测定的数据与玻璃标样的推荐数据,可以看出,本研究电子探针实验室(EPMA),已达到了比较高的精准度,可以得到高质量的数据,符合科学研究中实验室的要求。
(2)通过对MPI-DING玻璃标样主量元素的测定,其结果显示人工玻璃标样的性质均一,数据稳定,彼此间符合程度高。
在芜湖当日,早早醒来,踱步江边,众人或快走,或慢跑,或闲步遛狗……江中运沙的驳船鳞次栉比。一位老者以简易丝网,正在水流湍急的江边捕鱼,方才六点钟,已网上一两斤小鲳鱼,微型制氧机在铁桶的水里制造出无数咕噜噜的小泡儿。那些小鱼与老家小河里的模样近似,翘嘴鲳的一种。望着这些鱼儿,心底有什么东西仿佛又一次复活了。
(3)通过测定东太平洋大洋中脊火山玻璃的主量元素,得出其均一程度较好,其中中基性的玻璃大部分主量元素的均一程度高于酸性玻璃。对比岩性相似的天然火山玻璃和人工合成玻璃,合成玻璃的数据浮动基本平稳,偏差小,均一程度更高,尤其是酸性的合成玻璃数据明显比天然玻璃波动小。因此,人工合成玻璃比天然玻璃更适合于作为标准参考物质。
[1]周剑雄,毛水和. 电子探针分析[M].北京:地质出版社,1988:14-17.
[2]刘勇胜,胡兆初,李明,等. LA-ICP-MS在地质样品元素分析中的应用[J]. 科学通报,2013,36:3753-3769.
[3]Hu Z C, Gao S, Liu Y S, et al. Accurate determination of rare earth elements in USGS, NIST SRM, and MPI-DING glasses by excimer LA-ICP-MS at high spatial resolution[J]. Spectroscopy Letters, 2008, 41(5):228-236.
[4]Jochum K P, Stoll B, Herwig K, et al. MPI-DING reference glasses for in situ microanalysis: new reference values for element concentrations and isotope ratios[J]. Geochemistry Geophysics Geosystems, 2006, 7(2):217-222.
[5]Ross D K. Evaluation of MPI-DING glasses for use as electron probe standards[J]. Microscopy & Microanalysis, 2016, 22(S3):428-429.
[6]Jochum K P, Dingwell D B, Rocholl A, et al. The preparation and preliminary characterisation of eight geological MPI-DING reference glasses for in-situ microanalysis[J]. Geostandards & Geoanalytical Research, 2000, 24(1):87-133.
[7]Jochum K P, Wilson S A, Abouchami W, et al. GSD-1G and MPI-DING reference glasses for in situ and bulk isotopic determination[J]. Geostandards & Geoanalytical Research, 2011, 35(2):193-226.
[8]Jochum K P, Nohl U, Herwig K, et al. GeoReM: a new geochemical database for reference materials and isotopic standards[J]. Geostandards & Geoanalytical Research, 2005, 29(3):333-338.
[9]Tiepolo M, Zanetti A, Vannucci R. Determination of lithium, beryllium and boron at trace levels by laser ablation-inductively coupled plasma-sector field mass spectrometry[J]. Geostandards & Geoanalytical Research, 2010, 29(2):211-224.
[10]Jacob D E. High sensitivity analysis of trace element-poor geological reference glasses by laser ablation-inductively coupled plasma-mass spectrometry(LA-ICP-MS)[J]. Geostandards & Geoanalytical Research, 2010, 30(3): 221-235.
[11]Chen K Y, Yuan H L, Bao Z A, et al. Precise and accurate in situ determination of lead isotope ratios in NIST, USGS, MPI-DING and CGSG glass reference materials using femtosecond laser ablation MC-ICP-MS[J]. Geostandards & Geoanalytical Research, 2014, 38(1):5-21.
[12]Amini M, Eisenhauer A, Böhm F, et al. Calcium isotopes (δ44/40Ca) in MPI-DING reference glasses, USGS rock powders and various rocks: evidence for Ca isotope fractionation in terrestrial silicates[J]. Geostandards & Geoanalytical Research, 2010, 33(2):231-247.
[13]Hu Z C, Liu Y S, Li M, et al. Results for rarely determined elements in MPI-DING, USGS and NIST SRM glasses using laser ablation ICP-MS[J]. Geostandards & Geoanalytical Research, 2009, 33(3):319-335.
[14]Jochum K P, Pfänder J, Woodhead J D, et al. MPI-DING glasses: new geological reference materials for in situ Pb isotope analysis[J]. Geochemistry Geophysics Geosystems, 2005, 6(10).
[15]吴伟男, 刘希军, Castillo P R,等. 太平洋洋中脊火山玻璃主量元素地球化学特征[J]. 桂林理工大学学报, 2015, 35(4):786-795.