P507萃取色层分离ICP—AES法测定高纯氧化镱中14种稀土杂质元素

本文采用Ｐ５０７萃取树脂－盐酸体系色谱法对高纯氧化镱中１４种稀土杂质元素进行分离、富集,用ＩＣＰ－ＡＥＳ法测定其稀土元素含量。当上柱量为２００ｍｇＹｂ２Ｏ３时,所能达到的测定下限：Ｅｕ２Ｏ３为１μｇｇ－１;Ｙ２Ｏ３,Ｇｄ２Ｏ３,Ｄｙ２Ｏ３,Ｈｏ２Ｏ３,Ｔｍ２Ｏ３,Ｌｕ２Ｏ３为２μｇｇ－１;Ｌａ２Ｏ３,Ｅｒ２Ｏ３为４μｇｇ－１;Ｐｒ６Ｏ１１,Ｎｄ２Ｏ３,Ｓｍ２Ｏ３,Ｔｂ４Ｏ７为８μｇｇ－１;ＣｅＯ２为１６μｇｇ－１。５次取样分离,加入试验回收率在８８％—１１２％之间,相对标准偏差＜１０％。本方法可适用于纯度为９９．９５％—９９．９９％的氧化镱中１４种稀土杂质元素的测定。     

大孔树脂纯化菠萝皮黄酮类化合物的研究

通过静态吸附与解吸实验,比较7种树脂对菠萝皮黄酮类化合物的吸附和解吸特性,筛选出较优的菠萝皮黄酮类化合物吸附剂,并检测吸附流速、上样液浓度、pH值、洗脱流速、洗脱剂体积分数等动态吸附性能。结果表明:AB-8树脂具有较好的吸附和解吸效果,吸附流速1mL/min、上样液浓度2.25mg/mL、pH值6、洗脱流速0.5mL/min、洗脱剂体积分数90%条件下,AB-8型大孔树脂可用于菠萝皮黄酮类化合物的分离纯化。     

410哌啶树脂在分离富集中的应用研究 Ⅱ.岩矿中痕量金银铊镓铟的分离富集

研究了在HCl(或HBr)介质中410哌啶树脂对Au~(3+)、Ag~+、Tl~(3+)、Ga~(3+)和In~(3+)的吸附特性,考察了被吸附金属离子的分组洗脱或分别顺序洗脱条件,拟定了地质样品中上述诸离子的分离富集程序。经地质标样分析验证,方法可行。     

Retene and resin acid concentrations in sediment profiles of a lake recovering from exposure to pulp mill effluents

The stratigraphy of resin acids (pimaric, isopimaric, sandaracopimaric, dehydroabietic and abietic acids) and base neutral compounds (retene, tetrahydroretene, dehydroabietin and fichtelite) in sediments of a lake recovering after the mill closure from exposure to effluents from sulphite pulp mill was studied. The highest concentrations of these compounds were detected 1.5 km downstream from the effluent pipe in sediment depth of 7–11 cm. This sediment layer is approximately 30 yrs old. The highest concentration of resin acids was 1100 and of retene 3300 g/g d.w. The retene concentration observed is the highest reported in the literature so far. The results imply that high concentrations of retene may be common in sediments of Finnish lakes polluted by pulp mill effluents.     

水对树脂锚索锚固性能影响的试验研究

水对树脂锚索锚固性能具有影响,可导致锚索锚固失效。通过室内树脂锚固锚索拉拔试验以及长锚索锚固试验,系统研究了水对树脂锚索锚固性能的影响,得出水可降低锚固粘结强度约7 %,降低锚固体单轴抗压强度约12 %,减少有效锚固长度约10 %。研究结果对定量评价巷道锚索支护的安全性以及合理设计树脂锚索的支护参数具有重要意义。     

树脂分离富集质谱法测定矿石中痕量铂、钯、金

讨论了王水溶矿、树脂分离富集、在硝酸介质中用质谱法测定铂、钯、金。     

球状壳聚糖树脂对NO_2~-吸附特性的研究

以壳聚糖粉末为原料,采用反相悬浮交联法制备了球状壳聚糖树脂(MCR)。通过静态吸附实验,研究了pH和温度对MCR吸附NO-2的影响以及MCR对水溶液中NO-2的吸附热力学和动力学特性。结果表明,在酸性条件下,313~328K时,MCR对NO-2有较好的吸附性能。吸附过程符合Langmuir吸附等温线模型,属于单分子层吸附。吸附过程符合拟二级动力学模型,受粒子内扩散和液膜扩散联合控制。     

化学蒸气发生-无色散原子荧光光谱法测定地质样品中微量和痕量金

试样用王水分解,采用特定的金化学发生增敏试剂使金在硼氢化物-酸体系中产生挥发物质,将其导入原子荧光光谱检测系统,检测金的原子荧光信号。通过对仪器工作参数和化学蒸气发生参数的优化,使金的可检测信号同比提高20倍以上,同时降低共存离子对金的化学蒸气发生的干扰。对微量和痕量金的测定方法具有灵敏度高、检出限低、基体干扰少等优点。方法检出限为0.23 ng/g,准确度(ΔlgC,n=12)为-0.004~0.02,精密度(RSD,n=12)为2.62%~8.79%。经国家一级标准物质分析验证,测定值与标准值相符。     

微量岩石样品中Rb-Sr和Pb一步分离及高精度热电离质谱测试

采用30 μL Sr特效树脂微柱,一步分离微量岩石样品中Rb-Sr和Pb,其回收率均优于90％,流程试剂用量仅0.75 mL,分离时间约3h,Rb-Sr流程本底优于5 pg,Pb流程本底优于50 pg.本方法具有样品用量少、本底低、回收率高、分离效率高等优点.结合高灵敏度TIMS分析技术,可以实现微量岩石样品高精度Rb...     

Frankincense yield assessment and modeling in closed and grazed Boswellia papyrifera woodlands of Tigray, Northern Ethiopia

Boswellia papyrifera, a frankincense producing tree, grows in the arid lowlands of Ethiopia. It is a multipurpose tree species with ecological, environmental, cultural and socio-economic values. The resource has been declining due to unsustainable management. This study is aimed at estimating frankincense yield in a single production year, assessing the relationship between yield and dendrometric variables, and developing predictive yield models. We collected data of one harvesting season from randomly selected sample trees in an exclosure and a free grazing site. We found strong nonlinear relations between yield and dendrometric variables, which are useful for predictive yield modeling. A stepwise linear regression indicated that the yield from the sixth round of tapping could explain about 88% of the variation in annual yield per tree, a finding that can largely facilitate future yield monitoring. The frankincense yield was larger in the exclosure than in the adjacent free grazing site and the difference was statistically significant. To conclude, management of degraded B. papyrifera forest as exclosures should be strengthened to enhance the economic, environmental and cultural benefits from the species. Their effectiveness should be evaluated through yield monitoring and prediction.