液相色谱-质谱法对饮用水中六价铬的测定

建立了液相色谱分离、电喷雾质谱测定饮用水中六价铬的方法.水样经微孔滤膜过滤后直接进样,以乙腈-1.5 mmol/L四丁基氢氧化铵水溶液为流动相,Xterra~(TM) MS C_(18)色谱柱分离六价铬,使用单四极杆质谱,选择离子模式检测,监测离子为m/z 118、117、101、85,其中117为定量离子.Cr(Ⅵ)的线性范围为1.0 ～100.0 μg/L,方法定量下限为1 μg/L.在空白水样中分别添加1.0、2.0、10.0 μg/L的六价铬,测得平均回收率(n=5)依次为91%、94%、97%,相对标准偏差分别为12.2%、7.4%、3.5%.测定了42个饮用水样品,其中17批检出六价铬,检出量为1.2 ～15.4 μg/L.     

流动注射-氢化物发生原子吸收光谱法测定香烟接装纸中的痕量砷

将流动注射-氢化物发生和原子吸收光谱法有机的结合起来,探讨了流动注射-氢化物发生-原子吸收光谱法测定香烟接装纸中砷的最佳条件。样品经消解后,加入还原剂,使五价砷还原为三价,在盐酸介质中和硼氢化钾反应生成砷化氢,进入电热石英管原子化测定。检测结果相对标准偏差小于5%,加标回收率为96.7%~104%,方法检出限为0.18μg/L。     

电感耦合等离子体质谱法测定接装纸中砷、钼、镉、铊和铅

建立了一种同时测定接装纸中砷、钼、镉、铊和铅5种元素的电感耦合等离子体质谱分析方法,实验采用微波消解前处理样品,HNO3-H2O2-HF混合体系作消解剂。方法的加标回收率94.79%~114.6%,检出限0.002~0.18μg/L,相对标准偏差1.1%~4.4%(n=5),线性相关系数0.9996~1.000。用所建立的方法测定了17个牌号接装纸中砷、钼、镉、铊和铅的含量,结果发现:砷、钼、镉、铊和铅在接装纸中的含量较低,其平均值均低于1.0μg/g,接装纸中钼和铊两种元素的变异较大,镉的变异最小,其变异系数分别为98.5%、151.1%,53.0%。     

超高效液相色谱三重四极杆质谱法同时快速测定血浆和尿液中11种杀鼠剂

建立了血浆和尿液中11种杀鼠剂同时测定的超高效液相色谱串联质谱方法.血浆样品经乙腈沉淀、尿液样品经乙酸乙酯萃取,氮吹浓缩后用初始流动相复溶,在UPLC BEH C18柱上以甲醇-4 mmol/L乙酸铵为流动相进行梯度洗脱分离,负离子电喷雾多反应监测模式检测,基质标准外标法定量分析.血浆和尿液中11种杀鼠剂的加标回收率分别在68%～118%和62%～104%之间;日内相对标准偏差分别为5.6%～21%和4.1%～18%;日间相对标准偏差分别为8.5%～26%和7.1%～ 25% (n=6).除尿液中安妥的定量限为5 μg/L外,其余待测物的定量限均为1 μg/L.本方法灵敏度高,操作简单,适于中毒病人的快速诊断检测.     

柱后衍生-离子色谱法测定土壤和沉积物中的六价铬

为了提高土壤和沉积物中六价铬测定的灵敏度、精密度和正确度,建立了柱后衍生-离子色谱法测定六价铬的分析方法。样品经过预处理后,使用仪器进行定量分析。样品中的六价铬经过Prin-Cen Cr（VI）Spec Column型阴离子分析柱分离出来,分别使用硝酸铵体系溶液和二苯碳酰二肼溶液作为流动相和柱后衍生液,并使用TLD检测器进行六价铬的定量分析。结果表明,六价铬质量浓度在5～100 μg/L范围内线性关系较好,相关系数为1.0000,检出限为0.02 mg/kg。该方法在实际土壤和沉积物样品中的加标回收率为84.0%～94.0%,相对标准偏差为2.34%～11%。本方法与火焰原子吸收分光光度法（HJ1082-2019）相比,六价铬的测定不受试样盐分、pH值及三价铬影响,而且该方法具有灵敏度高、精密度好、正确度高和稳定性强的优点,适用于测定土壤和沉积物中的六价铬。     

亲水液相色谱三重四极杆质谱联用法快速检测尿液和血浆中河豚毒素

建立了快速检测尿液和血浆中河豚毒素的亲水液相色谱三重四极杆质谱联用分析方法.样品经乙腈沉淀、TSK-gel Amide-80亲水色谱柱分离后,采用电喷雾串联质谱多反应监测(MRM)模式检测,基体匹配标准外标法定量.尿液和血浆样品的线性范围分别为3～500 μg/L和1～200 μg/L,加标回收率分别为96%～108%和100%～105%,相对标准偏差小于9%和16%(n=6),样品的检出限分别为1.0和0.3 μg/L(S/N=3).本方法简单、快速、灵敏、特异性强.     

高效液相色谱法测定烟用接装纸中的六价铬

建立了一种测定烟用接装纸中六价铬的高效液相色谱法.方法以磷酸盐缓冲液萃取试样中的六价铬,加入二苯卡巴肼与六价铬进行显色配合反应,生成紫红色配合物,过滤后滤液经液相色谱柱分离,二极管阵列检测器分析测定.方法检出限为0.020 mg/kg,定量限为0.067 mg/kg,回收率为84.0%~99.8%,方法准确度和精密度均满足烟用接装纸的检测要求.     

液相色谱-电感耦合等离子体质谱法测定水嘴中六价铬和三价铬析出量

采用硝酸和氨水体系为流动相,等度洗脱方式,建立了液相色谱-电感耦合等离子体质谱(LC-ICP-MS)同时测定水嘴浸泡液中超痕量六价铬和三价铬的方法。考察了不同p H值、质谱条件等因素对实验体系的影响,使用动态反应技术(DRC)消除离子干扰。通过优化实验,实现了六价铬和三价铬的分离,避免了高含量三价铬对低含量六价铬出峰的干扰。测得六价铬和三价铬的检出限分别为0.013,0.028μg/L,线性范围分别0.02~10μg/L和0.04~20μg/L,加标回收率为76.0%~116.4%,相对标准偏差(RSD)分别为1.8%和2.8%。该方法样品用量小、检出限低、快速、准确,能够满足水嘴产品的检测需求。     

连续流动分析法测定土壤中的挥发酚

建立了连续流动分析仪测定土壤中挥发酚含量的方法。称取5 g左右的土壤样品,以磷酸调节p H值为4,加入适量水并进行蒸馏,馏出液用连续流动分析仪测定挥发酚含量。在4.96~200μg/L范围内,挥发酚的质量浓度与相对峰高线性相关,线性方程为y=235.31x+51.6,相关系数r~2=0.999 8,挥发酚的检出限为1.24μg/L。取2种土壤样品分别进行6次平行测定,测定结果的相对标准偏差分别为1.52%,1.56%。对2种挥发酚标准样品进行测试,相对误差分别为1.90%,2.08%,加标回收率在87.8%~95.5%之间。该方法适合大批量样品的连续分析,且无需使用三氯甲烷,与传统方法相比更安全环保。     

氢化物-原子荧光法测定食品容器及包装材料用聚酯树脂及其成型品中的微量锑

为建立简便、快速、高效测定食品包装材料中微量锑的方法,样品用4%乙酸处理后,利用氢化物-原子荧光法检测食品包装材料中的微量锑.结果表明,锑质量浓度在0～20 μg/L范围内呈现良好的线性,回归方程为y =87.284 C-17.440,相关系数r=0.999 9,检出限为0.028 4 μg/L,相对标准偏差RSD为0...     

Development of Paper Actuators Based on Carbon-Nanotube-Composite Paper

We propose a unique soft actuator—a paper actuator—based on carbon-nanotube-composite paper (CNT-composite paper), which is a composite of carbon nanotubes (CNTs) and paper. CNT-composite paper has highly efficient properties because of the contained CNTs, such as high electrical conductivity and semiconducting properties. We are considering using CNT-composite paper for various devices. In this study, we successfully developed a paper actuator. We determined the structure of the paper actuator by referencing that of bucky-gel actuators. The actuator operates using the force generated by the movement of ions. In addition to making the paper actuator, we also attempted to improve its performance, using pressure as an index and an electronic scale to measure the pressure. We investigated the optimal dispersant for use in paper actuators, expecting the residual dispersant on the CNT-composite paper to affect the performance differently depending on the type of dispersant. Referring to research on bucky-gel actuators, we also found that the addition of carbon powder to the electrode layers is effective in improving the pressure for paper actuators. We believe that the paper actuator could be used in various situations due to its ease of processing.     

Synthetic Paper

Synthetic paper can be made either by forming a web from synthetic fibers or by extruding a film from thermoplastic polymers. With suitable starting materials and appropriate treatment it is possible to equal the properties of conventional cellulose paper; in some respects, as in wet strength and dimensional stability, the synthetic papers are clearly superior.     

Ion Exchange Capacity of Chromatographic Paper

Abstract

The ion exchange capacities of Whatman No. 1 and Whatman CM81 chromatographic papers, with and without pre-washing, were determined chromatographically using lead nitrate and lead chloride. Mean values with standard deviations are reported. Statistical analysis indicates that pre-washing with acetic acid, perchloric acid, and disodium dihydrogen ethylene, diaminetetraacetate affects the capacity by the same amount at the 95% confidence limit.     

亚铈试纸的设计与制作

以中速定量滤纸作为基纸,依次用作为基纸改性剂的十六烷基三甲基溴化铵(质量分数0.5%)和作为显色剂的二甲酚橙(质量分数0.2%)浸泡、晾干,制成亚铈试纸。 用1.000×10^-5~1.000 mol/L的Ce³⁺标准溶液分别浸泡该试纸,制成11种颜色的标准比色卡。 建立了强酸性Ce⁴⁺/Ce³⁺混合液中Ce³⁺浓度的半定量试纸测定法。 将本法应用于再生电解液和模拟有机合成液中Ce³⁺ 浓度的测定,表明只需用质量分数20%的六次甲基四胺缓冲溶液将试液调整至pH值5.0~6.0,结果准确度良好,共存的Ce⁴⁺、对苯二酚、对羟基苯甲醛、1,10-二羟基蒽醌等组分均不产生干扰。 该试纸具有制作方法简单、廉价易得、检测快速、易操作等优点,可应用于生产流程中Ce³⁺浓度的快速检测。     

Thermoanalytical Contribution to the Study on Paper Degradation. Characterisation of Oxidised Paper

In this paper we studied the effect of oxidation on paper stability by means of simultaneous differential thermal analysis and thermogravimetry. In our laboratory we oxidised Whatman n. 1 chromatography grade paper and performed thermal analyses both on non-oxidised and on 6, 21 and 96 h oxidised samples. The results showed characteristic thermal effects, particularly performing the experiments under oxygen flow: it was noticed that the temperature of the main cellulose degradation DTA peak gradually decreases with the paper oxidation degree. An application of this method was extended to the study of differently oxidised parts of a 1948's book. This revised version was published online in July 2006 with corrections to the Cover Date.     

基于天然聚多糖的环境友好材料（II）-麻纤维和芦苇纤维多元醇的生物降解聚氨酯

以麻纤维和芦苇纤维制备的植物多元醇为原料,合成具有良好性能的生物降解 性硬质聚氨酯泡沫体,其密度40 kg/m~3左右,压缩强度150 kPa,弹性模量4 MPa 。而且多元醇中植物原料含量越大,其性能越好,这使植物原料的充分利用和材料 生产成本的降低成为可能。土壤掩埋实验表明,泡沫体有很好的土壤微生物降解性 。     

基于碳纸电极电化学快速合成聚苯胺纳米纤维

利用碳纸电极,采用循环伏安法、恒电流法和恒电位法等电化学聚合法快速合成了高氯酸掺杂聚苯胺纳米纤维.利用电子显微镜、红外光谱和四探针测定仪等对聚苯胺的微观形貌结构、掺杂度和电导率进行了研究.用循环伏安法对聚苯胺的电化学特征进行了分析.研究发现,3种方法合成的聚苯胺均为纳米纤维状结构,长度达3μm,直径为50~150 nm.其中,循环伏安法合成的聚苯胺纳米纤维的均一性和电导率均优于其它2种方法,其电导率高达5.97 S/cm.另外,聚苯胺合成速率顺序为恒电流法>循环伏安法>恒电位法,且恒电流法合成的聚苯胺纳米纤维电极材料的放电比容量最大(578 F/g),电容性能最好.     

Influence of Nanocellulose Structure on Paper Reinforcement

This article describes how crystalline or fibrous nanocellulose influences the mechanical properties of paper substrate. In this context, we used commercially available cellulose nanocrystals, mechanically prepared cellulose nanofibers dispersed in water or ethanol, and carboxy cellulose nanofibers. Selective reinforcement of the paper treated with the nanocellulose samples mentioned above was observed. The change in the fibre structure was assessed using scanning electron microscopy, roentgenography, and spectroscopy techniques. In addition, the effect of nanocellulose coating on physical properties was evaluated, specifically tensile index, elongation coefficient, Elmendorf tear resistance, Bendtsen surface roughness, Bendtsen air permeability, and bending strength. It can be concluded that the observed decrease in the strength properties of the paper after applying some NC compositions is due to the loss of potential disturbances in hydrogen bonds between the nanocellulose dispersed in ethanol and the paper substrate. On the other hand, significantly increased strength was observed in the case of paper reinforced with nanocellulose functionalized with carboxyl groups.     

一种适于胱氨酸纸色谱分离检测的理想展开剂

A developing solvent system,n-butanol-pyridine-water(1∶1∶ 1),was selected in this work. It is suitable for cystine identification with paper chromatography in its isolation process.     

Highly Flexible and Nonflammable Inorganic Hydroxyapatite Paper

A highly flexible and nonflammable inorganic hydroxyapatite (HAP) paper made from HAP ultralong nanowires is reported. The paper can be used for printing and writing and is promising for the permanent and safe storage of information, such as archives and important documents. The HAP paper is also an excellent and recyclable adsorbent for organic pollutants.