库伦滴定法测定岩矿试样中氯

本文提出用电生Ag~ 库伦滴定岩矿样品中痕量氯的方法。经对电解液组成、不同电解电流下的电流效率、干扰元素的分离等进行了实验研究,确定了最佳分析条件。实验结果表明:当测定氯量≥100μg时,回收率达99.5～99.9％,相对标准偏差0.33～0.03％;测定氯量≥10μg,回收率为98.6～98.9％;相对标准偏差2.5～0.58%;方法准确,重现性好,操作简便。用岩石和土壤一级标准物质检验及参加建材一级标准物质协作定值,结果满意。     

Cl/Br of scapolite as a fluid tracer in the earth's crust: insights into fluid sources in the Mary Kathleen Fold Belt,Mt. Isa Inlier,Australia

A combination of analytical methods, including trace element analysis of Br in scapolite by LA‐ICP‐MS, was employed to unravel the fluid–rock interaction history of the Mary Kathleen Fold Belt of northern Australia. Halogen ratios in the metamorphic and hydrothermally derived scapolite from a range of rock‐types record interaction between the host rocks and magmatic‐hydrothermal fluids derived from granite plutons and regional metamorphism. The results show that halite‐dissolution supplied at best only minor chlorine to fluids in the Fold Belt. Chlorine/bromine ratios in metamorphic scapolite indicate that fluids were dominantly derived from basinal brines formed from sub‐aerial evaporation of seawater beyond the point of halite saturation. This bittern fluid infiltrated the underlying sedimentary sequences prior to regional metamorphism. Zoned scapolite in a major late metamorphic mineralized shear‐zone records three discrete pulses of magmatic and metamorphic fluid, and it is suggested that fluid mixing may have assisted mineralization along and around this shear‐zone. As a crucial prerequisite for halogen fluid tracer studies using scapolite, we find in our samples that Cl and Br do not fractionate when incorporated in scapolite. Furthermore, unaltered rims of heavily retrogressed scapolite show indistinguishable Cl/Br signatures compared with fresh grains from the same sample indicating retrograde metamorphism did not significantly affect Cl and Br signatures in scapolite group minerals.     

Spatial distribution of atmospheric carbon monoxide over Bay of Bengal and Arabian Sea: Measurements during pre-monsoon period of 2006

Indian Space Research Organization (ISRO) conducted the ‘Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB)’ for a two-month pre-monsoon period in 2006 with the ocean segment covering Bay of Bengal and Arabian Sea. During this campaign, carbon monoxide (CO) was continuously monitored using a non-dispersive IR analyser. Quantifying CO in ambient air is vital in determining the air quality of a region. Being toxic, CO is a criteria pollutant, but it is a weak green house gas. Globally, very few measurements exist over marine atmospheres to study its temporal pattern; particularly in situ CO measurements are few over the Bay of Bengal and Arabian Sea for comparison. Present measurements indicate: (i) predominant single peak in the diurnal pattern of CO over the marine atmosphere in contrast to the double peak over the continent, (ii) the mean diurnal CO over the marine atmosphere showing an increasing trend towards evening hours, (iii) the amplitude of the AN peaks over the marine atmosphere was ∼ 100 ppbv, while at a remote island site in the Indian Ocean it was ∼ 5 ppbv and (iv) high CO values were observed close to continent and the long range transport by wind also caused CO highs.     

热带平流层CO浓度准两年振荡的位相变化特征

利用2005~2014年10年的卫星微波临边探测仪（MLS）资料分析了热带平流层一氧化碳（CO）体积混合比的年际变率,发现热带平流层CO浓度的准两年振荡（QBO）在30 hPa高度附近存在明显的位相变化特征。大气化学气候模式模拟结果表明,热带平流层CO的准两年振荡信号是化学和动力过程共同作用的结果,而动力作用主要是QBO引起的次级经向环流引起的物质传输。化学和动力过程共同作用导致热带平流层CO浓度的垂直梯度在30 hPa高度处发生反转,进而产生一氧化碳QBO信号的位相变化。此外,化学气候模式模拟结果还表明,与CO有关的化学过程不但可以减弱一氧化碳QBO信号的振幅,还可以在热带30~10 hPa高度范围内造成一氧化碳QBO和纬向风QBO信号之间约3个月的时间差。     

电厂温排水中余氯浓度预测

利用有限元分步杂交方法,对胶州湾海域潮流场进行了数值模拟。考虑余氯在水体中的化学反应,利用前人大量实验成果选取余氯衰减系数,建立胶州湾余氯的二维输运-扩散模型,并将此模型应用于青岛市黄岛发电厂三期温排水工程,预测了温排水中余氯的浓度分布及影响范围,为电厂冷却水排放口邻近水域的生态环境保护提供依据。     

大气扩散模型在气象应急保障中的应用

根据2008年11月12日广州市气象局在从化市举行的气象应急保障演习,利用气体扩散模型和事故现场气象参数,对污染事故的环境影响进行评估,为发生有毒有害化学品泄漏或爆炸期间气象应急保障提供技术支持,以便采取有效的措施,令污染事故对周围环境的影响和人员的伤亡降至最低。     

Determination of Fluorine and Chlorine by Pyrohydrolysis and Ion Chromatography: Comparison with Alkaline Fusion Digestion and Ion Chromatography

A method to determine F and Cl in silicate materials by employing pyrohydrolysis and ion chromatography (IC) is described. Pyrohydrolysis involved mixing a pulverised sample (∼ 40 mg) with V₂O₅ (∼ 160 mg) and heating to 1100 °C under a wet oxygen flow in a quartz tube. Recovery yields of F and Cl were ∼ 97% using a NaF + NaCl standard solution. Detection limits of the pyrohydrolysis-IC method for silicate samples were 0.36 and 0.69 μg g^-1 for F and Cl, respectively. Fluorine and Cl concentrations were determined in the reference materials JB-2, JB-3 and JA-1 from the GSJ; BCR-2, BHVO-1, BHVO-2, AGV-1 and AGV-2 from the USGS; and NIST SRM 610, 612 and 614 glasses. Precisions (RSD) for determinations of F were 1–13% (except NIST SRM 614) and 2–19% for Cl, and were dependent on the concentration and blank correction. Most results obtained in this study were in good agreement with those of previous studies. In comparison, the Na₂CO₃ + ZnO fusion method at 900 °C showed that the yields of F and Cl by alkaline fusion systematically decreased with fusion duration time. The yields were 84% and 83% for JB-3, inferring that F and Cl were lost in this alkaline fusion.     

Depth profiles of chlorofluoromethanes in the Norwegian sea

Depth profiles of the chlorofluoromethanes (CFM), CFCl₃ and CF₂Cl₂, have been obtained together with tritium profiles from water samples collected in the Norwegian Sea between surface and 2800 m depth. CFM analysis was performed by vacuum extraction of the dissolved gases from 500 ml samples of seawater and subsequent gaschromatographic measurement. The CFM concentration decreases with depth to about 10 percent of surface concentration at depths below 2000 m. The same behaviour is found for the tritium content. From a correlation of the CFM and tritium concentration the upper limit of the preindustrial atmospheric CFM levels can be estimated to 5 percent of the present day concentrations.     

On the variability and correlation of surface ozone and carbon monoxide observed in Hong Kong using trajectory and regression analyses

This paper investigates, the variability and correlation of surface ozone (Os) and carbon monoxide (CO) observed at Cape D'Aguilar in Hong Kong from 1 January 1994 to 31 December 1995. Statistical analysis shows that the average O3 and CO mixing ratios during the two years are 32±17ppbv and 305±191 ppbv, respectively. The O3/CO ratio ranges from 0.05 to 0.6 ppbv/ppbv with its frequency peaking at 0.15. The raw dataset is divided into six groups using backward trajectory and cluster analyses. For data assigned to the same trajectory type, three groups are further sorted out based on CO and NOX mixing ratios. The correlation coefficients and slopes of O3/CO for the 18 groups are calculated using linear regression analysis. Finally, five kinds of air masses with different chemical features are identified: continental background (CB), marine background (MB), regional polluted continental (RPC), perturbed marine (P*M), and local polluted (LP) air masses. Further studies indicate that O3 and CO in the conti     

Determination of Chlorine Contents in Geological Survey of Japan Reference Materials by Prompt Gamma Neutron Activation Analysis

We determined chlorine contents in nine GSJ (Geological Survey of Japan) reference materials (JB-1, 1a, 2, 3; JA-1, 2, 3; JR-1, 2) by prompt gamma neutron activation analysis, employing the standard addition method. Pressed powder disks of each reference material were used for neutron irradiation and gammaray measurement, after known quantities (25-200 μl) of sodium chloride solution were added. The influence of the nearby sodium peak overlap was checked, and fluctuations in the chlorine count rate were corrected using silicon as an internal standard. The slopes of calibration lines for seven reference materials (JB-1, 2, 3; JA-1, 2, 3; JR-2) and SiO₂ powders fall within 5% error, and their chlorine values were obtained from the intercepts. Chlorine contents in JB-1 a and JR-1 were also determined by using the calibration lines. Our chlorine values ranged from 26.1 to 934 μg g-¹, which agrees well with the previously reported values.