高浓度高Alb含量聚合氯化铝的制备及其水解行为研究

高浓度高Alb含量聚合氯化铝的制备及其相关性质研究一直是国内外学者研究的热点和前沿问题.本文首先采用化学法合成出AlT=0.2 mol·L-1,Alb高于85%的低浓度高Alb含量的聚合氯化铝,并在热侧温度55℃,冷侧温度20℃条件下进行膜蒸馏浓缩,首次成功地制备出总铝浓度AlT=2.52mol·L-1,Alb含量高达88%的高浓度高Alb含量的聚合氯化铝溶液.其次,对两种高Alb含量的低浓度和高浓度的聚合氯化铝新产品进行了水解特性研究,分别考察了稀释倍数、pH和稀释时间等因素对溶液中聚铝形态分布的影响.结果表明,稀释刚一开始时,Alb下降比较明显,但随着稀释倍数的增大,Alb含量降低较为缓慢,但在整个稀释过程中Alb含量仍能保持在70%以上;溶液的pH在碱性范围内对聚铝形态有一定影响,在碱性范围内,随着pH的增加,Alb含量逐渐增加,Alb、Alc含量逐渐减少,在酸性和中性较宽的范围内能够保持较高的Alb含量和较低的Alb含量;稀释时间对铝形态的影响较小,Alb聚合形态能够保持较长时间的稳定性.实验结果表明我们所制备的高浓度高Alb含量聚合氯化铝具有相当的化学稳定性.     

结晶硅中铁铝钙的快速分析

结晶硅中硅含量在97％以上。主要杂质元素是铁、铝、钙,其含量均不大于1.5％,其它元素甚微。根据结晶硅的组成,试样用HNO_3、HF溶解,加HClO_4冒烟挥发硅及HNO_3、HF。溶液稀释定容,分取适量溶液,分别测定铁、铝、钙的含量。铁用硫氰酸盐法,铝用络天青S法,钙用络量法进行测定。     

CAS-CPB分光光度法测定纸、纸浆和水中铝

为不断提高新闻纸的产品质量,给工艺研究提供参考数据,我们参照食品中铝离子的测定方法,探索了纸、纸浆和水中铝的测定方法。结果表明,于溶液pH6采用铬天青S(CAS)-溴化十六烷基吡啶(CPB)光度法测定铝,具有操作简便、快速、灵敏度高、准确度和精密度均好等优点,适用于新闻纸的分析。试剂配制铝标准溶液:用KAl(SO_4)_2·12H_2O按常法配制成含100微克铝/毫升储存溶液,再以此液稀释至含1微克铝/毫升的标准溶液;混合显色剂:(A)乙酸-乙酸铵缓冲液(77克乙酸铵和1.15毫升冰     

等离子发射光谱法测定三乙基铝中的铝

采用等离子发射光谱法测定三乙基铝中的铝,样品用乙醇稀释,H2SO4萃取,加热破坏酸液中的有机体.选择了合适的分析谱线和积分时间,方法简便,准确,快速,回收率为96%～103%.     

塞曼石墨炉原子吸收光谱法直接测定血液中痕量铝

采用偏振塞曼原子吸收法，以Ｃａ作基体改进剂，注入热解涂层石墨管中，直接测定用ＯＰ溶液稀释血液样品中的痕量铝，有效地消除了血液基体的干扰，克服了铝的记忆效应，从而提高了方法的测定灵敏度、重现性和准确度。     

电感耦合等离子体质谱法测定丙氨酰谷氨酰胺注射液中铝的含量北大核心CSCD

提出了电感耦合等离子体质谱法(ICP-MS)测定丙氨酰谷氨酰胺注射液中铝含量的方法。移取供试品7.5 mL共6份,分别置于6个15 mL塑料离心管中,各加入一定量的铝标准溶液,再用5%(体积分数)硝酸溶液稀释至刻度,摇匀,经0.22μm水膜过滤,得到供试品加标溶液系列,标准加入法定量。ICP-MS分析中选择雾化气稀释高基体样品引入-氦气碰撞(HMI-He)模式。结果显示:某供试品加标溶液中铝的质量浓度在30.00μg·L^(-1)内与其对应的响应值呈线性关系,检出限(3s)为0.88μg·L^(-1);对供试品加标溶液进行精密度试验,铝测定值的相对标准偏差(n=6)均小于2.0%;对同一供试品进行3个浓度水平的加标回收试验,回收率为101%~106%。方法用于12批丙氨酰谷氨酰胺注射液的分析,铝的检出量为20.00~31.22μg·L^(-1)。     

空气-乙炔火焰原子吸收法测定锌合金中铝

在原子吸收分光光度法中,由于铝易形成难离解的氧化物,灵敏度非常低,一般不能使用空气-乙炔火焰法,而是采用能提供较高原子化温度的一氧化二氮-乙炔火焰法或石墨炉法进行铝的测定.但在操作一氧化二氮-乙炔火焰时较危险,以及用石墨炉法测含铝大于0.x%的样品时,对试液要进行高倍数的稀释,操作比较费时,文献[3]对空气-乙炔火焰原子吸收法测铝进行了初步探讨.文献[4]报道了以含氮化合物作为增敏剂对铝的测定.本文采用空气-乙炔火焰原子吸收法和CTMAB作增敏剂进行铝的测定研究.可使铝的灵敏度提高5～6倍,检出限为10μg·ml~(-1).实现了空气-乙炔火焰法测定锌合金中铝,结果满意.1 试验部分1.1 仪器与试剂PF2380型原子吸收分光光度计     

用电位滴定法测定锌合金中的铝

过去我们曾用过铝-镍铬双金属电极以电位滴定法测定铜合金中的铝。今将该法略加修改应用于锌合铝的测定,亦得到了较满意的结果,并和容量法所测得的结果比较,结果一致。本法迅速,简便,适用于锌合金中铝的快速测定。分析方法:称取0.4000克样品于烧杯中,加盐酸(1:1)10毫升溶解。迅速过滤于300毫升烧杯中,用盐酸(1％)洗涤5—6次。滤液用氨水(比重0.9)中和至铝的沉淀不再溶解,立即滴加盐酸(6N)至沉淀完全溶解,并过量3毫升,以水稀释至80—100毫升,加入醋酸钠     

铝电解质中NaF/AlF_3比的测定

本文试验了以铝-铬天青S(CAS)-溴化十六烷基三甲基铵(CTMAB)形成的三元蓝色络合物作为滴定法测定铝电解质中NaF/AlF_3比的终点指示,有较明显的颜色变化,且灵敏度高、结果准确。实验部份 (一)主要试剂 1.三氯化铝溶液(一级):将氯化铝(AlCl_3·6H_2O)13.4克溶解于水,稀释至1000毫升,摇匀。 2.CTMAB溶液:0.05%.称取0.05克CTMAB加水60毫升微热溶解,冷却,以水稀释至100毫升、摇匀。     

4,4′-二胺甲基联苯搭桥的二苯并-18-冠-6环状二聚体的合成

在高度稀释条件下 ,二酰氯 (1)与二氨基二苯并 18 冠 6 (2 )反应 ,以高收率生成大环二酰胺 (3) ,3在甲苯溶剂中用SMEAH[二 (2 甲氧乙氧基 )二氢化钠铝 ]还原得到目标化合物——— 4,4′ 二胺甲基联苯搭桥的二苯并 18 冠 6环状二聚体 (4 ) .在吡啶溶剂中 4与 [6 0 ]富勒烯有弱的π 电子给体 -受体相互作用 .     

Determination of aluminum in high fat content biological materials using emulsions and direct current plasma

A new sample dissolution method employing an emulsion has been developed and evaluated for the determination of aluminum (Al) in high fat content biological samples. An emulsion is used to disperse the residual fat left over from nitric acid digestion to form a stable homogeneous moiety before aspiration into the direct current plasma (DCP) source. The method eliminates the need to filter the fat or extract fat soluble Al species from the undigested fat before analysis. Comparisons were made between the present method and two conventional sample dissolution methods for the determination of Al present in spiked and certified biological samples. The results indicated that the emulsification procedure offers simplicity, speed and improved accuracy/precision for the DCP determination of Al, especially for biological materials containing high amounts of fat and fat soluble Al complex(es).     

拟薄水铝石的快速分析

建立了一次溶样分别测定拟薄水铝石样品中A12O3、SiO2、Fe2O3、Na2O含量的快速测定方法。采用高压密封消化罐对拟薄水铝石样品进行溶解处理，分取适量样品溶液，测定A12O3、SiO2、Fe2O3、Na2O的相对标准偏差分别为0．20％、2．13％、0.31％、2．62％。     

电感耦合等离子体原子发射光谱法测定铬矿石中硅、铝、镁、铁

采用过氧化钠和氢氧化钠高温熔融铬矿石样品,以盐酸溶解熔块,合并溶液后用电感耦合等离子体原子发射光谱法测定样品中硅、铝、镁和铁的含量。选择212.412,308.215,285.213,238.204 nm分别作为硅、铝、镁、铁的分析谱线。用铬矿石标准样品配制标准溶液,对标准溶液的贮存方法进行了研究,对影响标准曲线稳定性的因素进行了讨论。SiO2、Fe2O3、Al2O3和MgO的线性范围依次为0.61%～14.64%,13.62%～27.74%,9.29%～15.17%和9.87%～21.49%。采用该法对铬矿石样品进行30d的连续测定,SiO2、Fe2O3、Al2O3和MgO测定值的相对标准偏差分别在0.51%～1.3%,0.45%～2.0%,0.50%～2.5%和1.4%～2.3%之间。     

Ion-chromatographic determination of trace anions with direct sample injection

The influence of the sample volume on the ion-chromatographic determination of anions was examined using various separation columns. Unlike conventionally used columns, Akvilain Al columns exhibit higher capacity factors for weakly retained anions. Thus, increasing the injected sample volume does not result in the masking of peaks of weakly retained anions by the negative system peak. The determination of anions at a level of several Μg/L is possible over a wide pH range. A double-loop system was used to eliminate the effect of residual ions in water used for the preparation of calibration solutions.     

电位滴定法测定模拟高放废液中的游离酸

本文研究了用电位滴定法测定模拟高放废液中游离酸的方法。用草酸钾做络合剂以消除Ｆｅ＾３＋、Ａｌ＾３＋、Ｎｄ＾３＋等多种水解离子的影响，用标准碱直接进行电位滴定，即可快速准确地测定模拟高放废液中游离酸的含量。方法的相对标准偏差为１．８％，标准加入回收率为１００－１０１％，能为放射性废物固化试验提供可靠的分析数据。     

Al3+对电位滴定仪测定游离酸的干扰及其消除研究

溶液中Al3+易水解,对游离酸的测定存在严重干扰。本文以NaF溶液掩蔽Al3+,用自动电位滴定仪测定含Al3+溶液中的游离酸含量,通过溶液化学分析论证了NaF溶液掩蔽Al3+的可行性。NaF掩蔽-自动电位滴定法测定含Al3+溶液中游离酸含量的精密度实验RSD小于2.0%,方法的加标回收率在98.00%～103.00%之间,与手动滴定法对比可靠性检验结果t=0.25;以上结果表明该方法具有准确度高、重复性好的优点。     

电感耦合等离子体原子发射光谱法测定铬矿中5种化学成分

提出了用电感耦合等离子体原子发射光谱法(ICP AES)测定铬矿中铁、铝、硅、镁和钙含量的方法。通过试验确定以混合熔剂碳酸钠-碳酸钾-硼砂质量比2比2比1熔融样品,熔块用硝酸(15+80)溶液浸取,分取部分试液按选定条件进行ICP-AES分析。选择393.37,251.61,271.44,396.15,279.55nm 5条谱线分别作为钙、硅、铁、铝及镁的分析线。用铬矿国家标准样品(BGBW 07201、GSBD 33001.3)制作标准曲线。按此方法对一种国家标准样品(GSBD 33001.2)和两种已知样品(Cr-2、72-Cr-01)进行分析。测定值与认定值基本一致,测得方法的回收率在99.0%～101.5%之间,相对标准偏差(n=6)在0.05%～0.78%之间。     

Application of factorial design in optimization of ultrasonic-assisted extraction of aluminum in juices and soft drinks

A sample preparation method based on ultrasound-assisted pseudo-digestion of Al from Juices and soft drink samples under ultrasonic effect has been described. A Plackett-Burman experimental design was used as a multivariate strategy for the evaluation of the effects of varying several variables at once. The effects of five different variables preintensification time (without ultrasonic stirring), intensification time in ultrasonic bath (UB), temperature of UB, two acid mixtures (HNO(3)-H(2)SO(4)-H(2)O(2) and HNO(3)-H(2)O(2)), on the recovery of Al have been investigated. From these studies, certain variable showed up as significant, and they were optimized by a using 2(3)+star central composite design, which involved 16 experiments. The best conditions for pseudo-digestion were as follows: a preintensification time 10min, intensification time 20min, volume of acid mixtures 3.0ml and temperature of ultrasonic bath 80 degrees C. A conventional acid digestion on electric hot plate was used to obtain total Al for comparative purpose. Final solutions obtained from both methods, were analysed by electrothermal atomic absorption spectrometry. Analytical results for the Al by ultrasound-assisted pseudo-digestion, and conventional wet digestion methods showed a good agreement, thus indicating the possibility of using ultrasonic-assisted digestion sample preparation instead of intensive treatments inherent with the acid digestion methods on electric hot plate. The procedure proposed allowed the determination of Al with detection limit (3alpha/s) 10mugl(-1).     

Application of ZrC-coated tubes to the determination of aluminum in serum by graphite furnace atomic absorption spectroscopy

An improved method for the determination of aluminum in serum by atomic absorption spectrometry with a graphite furnace is presented. The method is suitable for the analysis of serum samples having normal and elevated aluminum content. The serum sample can be analyzed diluted or undiluted because the selected temperatures program minimizes the matrix interferences. High temperatures are made possible by the use of graphite Zr-coated tubes. The detection limit is 0.7 μg Al/liter. The coefficient of variation is 3.2% for serum concentration of 5 μg Al/liter and 1% for serum concentration of 50 μg Al/liter.     

Study of heterogeneities in steels and determination of soluble and total aluminium and titanium concentration by laser ablation inductively coupled plasma mass spectrometry

A methodology for bulk analysis of Al and Ti and for determination of soluble and total Al and Ti concentration in steel samples by laser ablation inductively coupled plasma mass spectrometry was developed. The spatial distribution (both at surface and within the sample) of the insoluble fraction of Al and Ti was also qualitatively estimated. Certified reference materials (CRMs) SS-451 to 460 (carbon steel) and 064-1 (Nb/Ti interstitial free steel), from BAS, and JK 2D (carbon steel) and JK 37 (highly alloyed steel), from SIMR, were studied. It was demonstrated that the insoluble fraction of Al and Ti is heterogeneously distributed. A series of nine glass samples (fused beads) with fixed Fe content and different Al and Ti contents was prepared by melting appropriate amounts of Fe₂O₃, Al₂O₃ and TiO₂ with a lithium tetraborate–sodium carbonate mixture. Quantitative determinations were performed by using calibration graphs obtained from the synthetic fused beads, with ⁵⁷Fe as internal standard; line scan laser sampling mode was used, focusing the laser beam at the sample surface. The optimized laser operating parameters were: laser pulse energy of 1.5 mJ, pulse repetition rate of 5 Hz, scanning speed of 5 μm s⁻¹ and preablation time of 20 s. The concentrations obtained for bulk analysis of CRM samples corresponded with the certified values within the experimental uncertainty. An acceptable concordance between certified and found values was attained for the determination of soluble and total Al and Ti in CRM 064-1 sample.