ICP-AES法测定铍铝合金中银、锗和钴量

建立了电感耦合等离子体原子发射光谱法测定铍铝合金中银、锗和钴量的分析方法。采用硫酸(5+95)10 mL和硝酸(1+1)10 mL溶解试样。研究了元素分析谱线的选择、铍和铝基体对银、锗和钴测定的干扰等实验条件,并对仪器工作参数的选择进行了优化,确定了最佳的实验条件,各元素分析谱线依次为Ag 338.289 nm、Ge 209.426 nm、Co 238.892 nm,建立的校准曲线各元素的线性相关系数均在0.9995以上。铍铝合金样品分析中,加标回收率为97%~103%,重复测定结果的相对标准偏差为0.70%~0.90%(n=8)。     

超声波消解测定土壤中锑、铍的方法

对土壤样品先进行超声波消解,再使用电感耦合等离子体原子发射光谱(ICP-AES)对锑、铍元素进行测定;样品加入硝酸、氢氟酸经超声波消解,再高氯酸冒烟飞除硅。在5%的盐酸介质中,于优化后的仪器条件下测定锑、铍元素。本方法方法回收率在93.0%~102.5%之间,方法标准偏差小于3.0%,该方法流程简便,分析快速,结果较准确。     

铝合金中硅、镁、铜、铁、锰元素的测定

铝合金常常用回收的废铝重新进入熔铸冶炼,而废铝中硅、镁的含量很低,为了达到铝合金的硬度和可塑性,便于挤压成型,需检测铝锭中硅、镁、铜、铁、锰元素的含量.采用分光光度法测定了工业生产过程铝合金中硅、镁、铜、铁、锰元素的含量.     

ICP-OES测定铝合金中多元素的方法探索

探讨电感耦合等离子体发射光谱法(ICP-OES)同时测定铝合金中硅,铁,镁,铜,锰,铬和锌等七种元素的方法。通过选择各元素的最佳光谱线和优化工作条件,得出该方法快速,简便,分析周期短,符合生产要求。测定的元素含量范围为0.060%~0.779%。用该方法测定铝合金中的硅,铁,镁,铜,锰,铬和锌,相对标准偏差RSD为小于3%,回收率为96.2%~102%。     

ICP-OES法测定纯铝中铁、锰、硅、铜、镁、钛、锌元素含量

本文研究了使用电感耦合等离子体发射光谱法同时测定纯铝中痕量元素铁,锰,硅,铜,镁,钛,锌通过选定合适的样品消解方法、仪器最佳测定条件和分析谱线波长,来达到准确测定的目的。方法经回收率及标准样品测定试验,快速方便,准确可靠。     

电感耦合等离子体发射光谱法测定镁-锌-锆合金中痕量铍含量

本文建立了等离子体发射光谱法测定镁-锌-锆合金中痕量铍含量的方法,基于等离子体发射光谱法快速简便、灵敏度高和选择性好的优点,通过对分析谱线的选择,观测方向的选择,基体与共存元素干扰的分析,方法的线性相关系数可达0.9999以上,通过加标回收率试验以及对标准样品与实际样品中铍含量的测定,测定结果与认可值吻合较好,RSD均小于5%(n=8),回收率在98.33%~107.5%之间,该方法的准确度与精密度均达到了要求,实现了镁-锌-锆合金中0.0002%以下痕量铍含量的准确测定。具有简便、快速、稳定、准确等优点。     

火焰原子吸收光谱法测定苋菜中8种矿物元素

用空气-乙炔火焰原子吸收光谱法对苋菜中钾、钙、镁、铁、锌、铜、锰、铅8种矿物元素进行了测定,对样品前处理方法、酸度、共存元素干扰及元素线性范围进行了实验。在选定的实验条件下,可以用火焰原子吸收光谱法对苋菜中8种元素进行分别测定,互不干扰。方法的相对标准偏差为0.08%~3.17%(n=5),加标回收率为91.5%~102%。     

ICP-AES法测定低碳锰铁中磷、铁、硅

采用稀硫硝混酸溶解试样,ICP-AES法同时测定低碳锰铁中磷、铁、硅,通过对溶样酸、锰基体的研究,确定了分析条件。该方法灵敏度高,具有良好的精密度和准确性,回收率在94%～104%。     

分光光度法测定铝合金中铜、铁、锰的含量

1 前言 装饰门窗用的铝合金生产中,除了含有必需的元素镁与硅外[1],还含有铜、铁、锰等杂质元素,这些元素是影响铝合金阳极氧化膜光洁度的主要因素,其含量越高,铝表面的光洁度会越差,其含量的高低将严重影响铝合金的表面质量[2].对其进行准确的测定,并对这些元素加以控制,对铝材的质量起到非常重要的作用[3,4].本文采用分光光度法对铝合金中铜、铁、锰的含量进行测定,并对测定的条件进行了探讨.结果表明,其准确度和精密度均能满足铝合金生产的分析要求.     

ICP法测定铍矿中氧化铍含量

本文通过具体实验研究了电感耦合等离子体发射光谱技术(ICP-AES)测定铍矿中铍含量的方法。实验测得氧化铍的平均含量为8.12%,RSD为1.32%,加标回收率均在90%-110%范围内,且加标回收率的RSD=1.91%,加标回收良好,是种极好的铍矿中铍含量测定方法。     

Chemical Composition and Physical Properties of High Oleic Safflower Oils (Carthamus tinctorius,Var. CW88-OL and CW99-OL)

Chemical composition and physical properties of CW88‐OL and CW99‐OL cultivars of high oleic safflower seeds and their hexane‐extracted oils were determined. Dry‐based seed composition of CW88‐OL and CW99‐OL was: moisture = 4.29 and 4.23 %, oil = 42.29 and 46.44 %, Crude protein = 20.94 and 16.41 %, neutral detergent fiber = 28.11 and 28.49 %, ash = 1.55 and 2.01 %, phosphorus content = 2033 and 3995 mg/kg, respectively. Major fatty acids in oils were ~78 % oleic (O), ~13 % linoleic (L), ~5 % palmitic (P) and ~2 % stearic (St) acids, for both cultivars. The main triacylglycerols were OOO (~50 %), OOL (~20 %), SOL + OPO (~10 %), and LLP (~5 %). The oil composition of CW88‐OL and CW99‐OL in main minor components was: α‐tocopherol = 582 and 551 mg/kg, total sterols = 3996 and 3362 mg/kg, phospholipids = 22 and 21 mg/kg and wax content = 70 and 74 mg/kg. For both cultivars, density and viscosity of the oils between 25 and 55 °C varied from 903.4 to 912.6 kg/m³ and 63 to 23 mPa.s showing linear and exponential behaviors, respectively. The refractive index was 1.4694. The CIELab color parameters were: 89.69 and 89.53 (L*), ?3.72 and ?3.07 (a*), and 47.28 and 47.78 (b*) (CW88‐OL and CW99‐OL, respectively). Thus, the high oil content of the seeds and nutritional quality of the oil accompanied by low levels of waxes and phospholipids makes the cultivars studied promising for producers and consumers.     

反相高效液相色谱法同时测定桂油生物催化反应中肉桂醇、苯甲醛、苯乙酮、肉桂酸和肉桂醛

建立了快速测定桂油生物催化反应中肉桂醇、苯甲醛、苯乙酮、肉桂酸和肉桂醛的反相高效液相色谱方法。色谱条件:采用Kromasil-100A C18柱(250 mm×4.6 mm,5μm),以乙腈-甲醇-水-冰醋酸(体积比36:6:58:0.02)为流动相,流速为1.0 mL/min,检测波长为205 nm,柱温为室温。结果表明,肉桂醇在1.03～82.16μg/mL范围内呈良好线性关系(r=0.999 9);苯甲醛在1.10～87.92μg/mL范围内呈良好线性关系(r=0.999 9);苯乙酮在1.06～84.48μg/mL范围内呈良好线性关系(r=0.999 8);肉桂酸在1.30～104.16μg/mL范围内呈良好线性关系(r=0.999 8);肉桂醛在1.21～96.48μg/mL范围内呈良好线性关系(r=0.999 2)。肉桂醇、苯甲醛、苯乙酮、肉桂酸和肉桂醛的平均回收率分别为99.8%,100.7%,100.6%,96.4%和100.7%,相对标准偏差(RSD)分别为3.4%,3.3%,2.0%,1.8%和5.5%。     

广州市1992～2007年乙型肝炎疫苗接种率与发病趋势分析

目的分析广州市1992~2007年乙型肝炎疫苗接种率与发病趋势,为乙肝免疫和防治策略提供依据。方法对广州市1992~2007年出生的儿童乙肝疫苗接种率及乙肝发病率进行调查。结果接种初期(1992~1994年)疫苗接种率为63.14%,接种后期(2002~2007年)为95.72%。1992~2007年1~16岁年龄组乙型肝炎发病13699例,总发病率在(26.21~122.74)/10万之间,其中接种初期发病率最高,为122.74/10万,接种后期最低,为26.21/10万,下降了78.65%。1~5岁、6~10岁和11~16岁组乙肝发病呈逐年下降趋势,降幅分别为54.82%,75.04%和83.04%。接种后期与接种初、中(1995~2001年)期比较,HBsAg阳性率分别下降了80.80%和79.13%,抗-HBs阳性率分别升高了8.70%和13.15%,抗-HBc阳性率分别下降了23.24%和4.29%。结论广州市推广新生儿乙肝疫苗接种已取得良好效果。     

DME conversion using high flux tubular membrane reactors

High flux tubular membrane reactors were designed for dimethyl ether (DME) steam reforming. Considering the facile scale-up and high flux of hydrogen, tubular stainless steel supports were employed for the membrane reactors. At 500°C, DME conversion reached ~100%, while hydrogen recovery reached 20%. However, contamination by CO was rather high (>1%), making this process unsuitable for proton exchange membrane fuel cell applications, which require a CO concentration of <100 ppm. This result showed that an additional polishing step was needed to reduce the CO concentration. Membrane reactors were further modified to perform an water–gas shift reaction on the permeate of the membrane reactors by employing a fixed bed reactor, which yielded high-purity hydrogen (~99%) along with a low CO content (<20 ppm).     

Two-Stage Optimization of Coliforms,Helminth Eggs,and Organic Matter Removals from Municipal Wastewater by Ozonation Based on the Response Surface Method

In this study, a set of municipal wastewater (MWW) samples from an actual residual water treatment plant was treated by ozone. The residual water was characterized in terms of organic load and biological contaminants: total coliforms (TC), fecal coliforms (FC) and helminth eggs (HE). Initial values of these parameters were 2.8 × 10⁷ MPN/100 mL, 8.48 × 10⁶ MPN/100 mL, and 470 L^?1, respectively. The experimental setup considered the modification of pH and ozone dose as independent variables. Three different initial pH values (4.0, 7.0, and 11.0) and three different ozone concentrations (6, 15, and 30 mg/L) were used to investigate the pH ozone dose effect. The efficiency of ozone-based treatment was determined by the reduction of the microbiological indicators (TC, FC, and HE) and physicochemical parameters (COD and turbidity). The response surface method was used to determine suboptimal reaction conditions. These conditions were obtained using a two-stage procedure. The conditions under which both microbiological and organics were better removed corresponded to pH 7.8 and ozone concentration of 15.5 mg/L. A decline of biological indicators of 99% for TC, 99% for FC, and 99% for HE was obtained under the same reaction conditions. The reduction of chemical oxygen demand (COD) and turbidity was 75% and 85% under the same operation conditions, respectively.     

等离子体引发甲基丙烯酸二甲氨基乙酯的水溶液聚合

将水溶性单体甲基丙烯酸二甲氨基乙酯 (DM) ,用低温等离子体引发其水溶液聚合。重点考察了多种因素对聚合物产率的影响 ,实验结果表明 :单体质量分数以48.5 3% ,等离子体放电功率以 10 0 W为好 ;在实验范围内 ,随放电时间 (0～ 6 5 s)及后聚合时间 (3～ 2 4d)的延长 ,聚合物产率增加。聚合反应对溶剂具有较大的选择性 ,其中以水溶剂效果最佳。另外 ,聚合物具有较大的吸水能力 (10 0 g/ g)。     

两种检测人凝血因子Ⅸ中肝素含量方法的验证及比较

目的验证人凝血因子Ⅸ中肝素含量的两种测定方法(凝固法及全自动血凝仪测定法),并进行比较。方法分别验证凝固法的准确度、精密性及全自动血凝仪测定法的线性、准确度、精密性。结果凝固法检测3批次原液的6次加标试验回收率为92%~100%,3批成品连续6次测定结果的CV为11%~16%;全自动血凝仪测定法在肝素浓度0~0. 5 IU/mL范围内,与凝集时间的对数呈良好的线性关系,r均> 0. 99,检测3批原液6次加标试验的回收率为98%~101%,3批成品连续6次测定结果 CV为2%~3%。结论两种方法均具有良好的准确度及精密性,均可用于人凝血因子Ⅸ中肝素含量的测定,全自动血凝仪测定法更快速、准确。     

电感耦合等离子体串联质谱法测定高纯镍金属中痕量硒

使用串联四极杆电感耦合等离子体质谱仪ICAP TQ测定高纯镍中痕量硒元素。通过测定78Se和80Se两种同位素,对比考察了H_2和O_2分别作为反应气时对检出限和等效背景溶度的影响,从而确定了使用O_2作为反应气,能更加彻底地消除Ni基体产生的多原子离子干扰,且经质量转移,将测定Se~+转变为测定SeO~+,达到准确测定高纯镍金属中痕量硒的目的。实验测得了O_2模式下的~(78)Se和~(80)Se的检出限分别为2.4ng/L和8.3ng/L,加标回收率为97%～99%。     

Remediation of phenanthrene contaminated soils by nonionic surfactants enhanced soil washing coupled with ozone oxidation

In the present work, soil washing followed by ozone oxidation for remediation of phenanthrene (PHE) contaminated soils was investigated. The PHE removal efficiencies of TX-100 and Brij-35 at 3000 mg/L were 80.2% and 73.8%, respectively. In the ozone oxidation process, the oxygen supply rate was more rapid and the ozone concentration in the water rose quickly after 2 h. The degradation efficiencies for PHE, Brij-35, and TX-100 at 20 mg/L ozone concentration were 99%, 99%, and 45%, respectively. Our investigation suggests that coupling ozone oxidation with surfactant-enhanced soil washing is an effective method for removing hydrophobic compounds from soils.     

全差示吸光光度法测定矿石中广泛含量钛

全差示吸光光度法精密度好（相对偏差可降至０．４％￣０．２％以下），灵敏度高（比普通法可提高１０￣２０倍），测定范围广（可以从痕量至高含量０．００Ｘ￣９９．Ｘ％），我们用此法采用过钛酸法测定广泛含量的钛。在选定的条件下测定微克￣２０ｍｇ ＴｉＯ２／１００ｍＬ结果令人满意。