浊点萃取-FAAS法测定化妆品中六价铬

提出了浊点萃取-火焰原子吸收光谱法测定化妆品中痕量六价铬的方法。考察了溶液pH、APDC用量、Triton X-114用量、平衡温度及时间等条件对浊点萃取率的影响,在优化条件下,对化妆品进行测定。该方法测定铬的检出限为0.026 mg/L,相对标准偏差为1.52%。结果表明：市售多数化妆品中的铬含量超过国家标准,须引起质量监督部门的注意。     

浊点萃取-192紫外可见分光光度法测定痕量铝

研究了浊点萃取(CPE)-紫外可见分光光度法测定痕量铝离子的新方法,利用非离子表面活性剂Triton X-114对铝试剂与铝离子形成的络合物进行浊点萃取。探讨了影响浊点萃取及测定灵敏度的因素。在最佳条件下,铝离子的富集倍率为13.5倍,检出限为0.33μg/L,RSD为0.2%(n=6),铝离子含量在10~150μg/L范围内服从比尔定律。本法对实际样品中的铝进行富集和测定,结果令人满意。     

浊点萃取-石墨炉原子吸收测定自来水样中的铁

建立了一种用于环境水样中痕量铁元素测定的方法。该方法通过浊点萃取对环境水样中痕量铁进行预富集分离,并与石墨炉原子吸收分光光度法联用进行检测,在最优化条件下,测定水中的痕量铁,RSD为2．06％,检测限为1．2×10^-2μg／L。     

浊点萃取-高效液相色谱法测定某些中草药中铜的研究

基于浊点现象,建立了以双硫腙为配位剂、TritonX-114为表面活性剂的浊点萃取-高效液相色谱法测定中草药中痕量铜的新方法。研究了溶液pH值、配位剂的浓度、表面活性剂的浓度、平衡温度和平衡时间、流动相类型等实验条件对浊点萃取及铜测定的影响。在最佳试验条件下,该方法的线性范围为0．1—120μg·L^-1,相关系数达0．997-0．999,铜的检出限达到0．1μg·L^-1。相对于传统的液相色谱分析法灵敏度提高了18倍。该方法成功用于中草药样品中铜的测定并获得了满意的结果。     

浊点萃取-火焰原子吸收法测定水中的痕量钴

研究了以DDTC作为配位剂,浊点萃取预富集-火焰原子吸收法应用于水样中痕量的钴测定的实验方法;对实验条件进行了优化,用该方法对水样中的钴含量进行了测定,并对此方法的可靠性和精确性进行了验证。     

浊点萃取—火焰原子吸收光谱法测定痕量镉

以1-（2-吡啶偶氮）-2-萘酚（PAN）为络合剂、以Triton X—100为表面活性剂进行浊点萃取建立了浊点萃取——火焰原子吸收光谱法测定痕量镉的方法。探讨了络合剂的浓度、溶液的pH,缓冲溶液的浓度、表面活性剂的浓度等影响浊点萃取的因素。该方法用于自来水、湖水、雨水中痕量镉的测定,具有低毒,高效,安全,简便等特点。     

浊点萃取技术的应用

浊点萃取技术(Cloud point extraction,简称CPE)是近年来出现的一种新兴的环保型液-液萃取技术,它以表面活性剂的浊点现象为基础,通过改变实验参数(如溶液的pH值、温度等)引发相分离,作为测定环境样品中痕量金属离子的前处理手段,在分离和富集痕量金属离子方面起着重要作用.     

氨基酸在铜离子浊点萃取中的应用

采用紫外光谱分析技术,考察了以不同氨基酸为络合剂时铜离子的浊点萃取效率,确定最佳的络合剂为甘氨酸。并将浊点萃取和紫外分光光度法联合应用于环境水样中痕量铜离子的分离和测定,效果较好。     

食品容器内壁的腐涂料中痕量铅的测定

采用标准加入法，用APW－DDTC－MIBK-环己烷体萃等取处理后涂料中痕量铅，并利用空气－乙炔火焰原子吸收法测定其含量，建立了优化的萃取和测定条件，并对可能存在的干扰元素进行了干扰实验。     

火焰原子吸收光谱法测定痕量铅的研究与应用

综述了近年来火焰原子吸收光谱法测定痕量铅的研究进展。从火焰原子吸收光谱法在环境、食品及其它样品中铅的测定分析进行了归纳和评述,展望了火焰原子吸收光谱法测定痕量铅未来的研究方向和发展前景。     

测定水中石油类液液萃取仪的比较和选择

文章分别从系统误差、乳化现象、工作效率、便利性和经济实用性比较了四种商品化的液液萃取仪在测定水中石油类前处理中的应用。吹气式自动萃取仪易导致四氯化碳的挥发损失;射流萃取仪不易清洗干净;搅拌式萃取仪具有机械破乳的作用;震荡萃取仪工作效率高,但价格昂贵。最后对萃取仪的使用和选择提出了建议。     

Lead stabilized uPVC potable pipe: Extraction results under NSF standard number 61

Lead stabilized uPVC potable water pipe was successfully formulated and produced to comply with the health effects criteria established by the National Sanitation Foundation (NSF). The maximum allowable level (MAL) of lead extraction, from products that come in contact with drinking water, is specified in the new NSF Standard Number 61 as 5.0 µg/L (or, 5 parts per billion, ppb). Samples of uPVC pipe stabilized with 0.3 phr (parts per hundred parts of resin) of tribasic lead sulfate stabilizer were tested in accordance with the procedures of NSF Standard Number 61, and the extraction results were all below 2 ppb lead at both pH 5 and pH 10. Continued, daily extractions showed that the amount of lead released into drinking water fell below quantitation levels within one week, in agreement with previous findings reported in the scientific literature. Thus, lead stabilized uPVC potable water pipe has been shown to be safe and in compliance with established health effects criteria.     

Extraction of ferulic acid from oil palm pressed fiber by a choline chloride based deep eutectic solvent

Results on the extraction of ferulic acid from palm pressed fiber using deep eutectic solvent (DES) of choline chloride-acetic acid (ChCl-AA) and choline chloride-citric acid (ChCl-CA) are reported. Acetic acid was found to be a better hydrogen bond donor to choline chloride than citric acid for the extraction of ferulic acid. Influence of water content in both DES was investigated whereby ChCl-AA and ChCl-CA experienced a drop in viscosity from 9.678 to 1.429 and 22.658 ± 1.655 mm²/s, respectively as the water content in the DES increased from 0 to 50 wt%. The drop in viscosity contributed to higher extraction efficiency in which 41,155 ± 940 mg/kg ferulic acid was obtained after 6 h reflux when ChCl-AA with 30 wt% water was used for the extraction compared to 30,940 ± 621 mg/kg when neat ChCl-AA was used. Further increase in water content in the DES however, did not lead to higher extraction efficiency. Although viscosity of the DES could be improved with the addition of water, there is a threshold where the DES could tolerate the presence of water without changing its solvent behavior. Surface response model revealed that interaction between heating duration and water content in DES, as well as second order effect of both heating duration and water content in DES played important roles in the extraction of ferulic acid from oil palm pressed fiber. The optimum condition for extraction of ferulic acid from palm pressed fiber was heating for 6 h with DES containing 30 wt% water.     

Rapid extraction of lead(II) from succinate media with n-octylaniline in toluene

The distribution equilibrium of lead(II) species between aqueous succinate media and n-octylaniline was studied as a function of the concentrations of extractant in organic phase, weak organic acid concentration, different diluents and effect of shaking period on extraction. The quantitative extraction of lead(II) was observed with n-octylaniline in toluene from 0.0035 to 0.0065 M sodium succinate media in the pH range 8.0–8.3. The metal ion was stripped out from organic phase with water and determined complexometrically with disodium salt of EDTA or spectrophotometrically with PAR. The extraction of lead(II) was quantitative in most aromatic solvents, such as benzene, toluene and xylene, and oxygen containing solvents, amyl alcohol and n-butanol, and also in carbon tetrachloride. The stoichiometry of the extracted species was determined on the basis of slope analysis and found to be 1:2:2 (metal: acid: extractant). As an application the system was used for selective extraction of lead(II) from its binary mixture with Zn(II), Tl(I), Tl(III), Bi(III), Al(III), Cu(II), Th(IV), U(VI), Sn(IV), Sb(III) and Ca(II). The distribution coefficient for lead(II) in succinate media was of higher magnitude than salicylate and malonate media. This developed method was successfully applied for the analysis of lead(II) in real samples such as alloys, ores and pharmaceutical materials.     

钡存在下铅的测定

介绍了当含铅物料中w（钡）〉2%时,在常规配位滴定法测定铅的基础上,采用浓硫酸高温强热处理物料,使铅、钡成为Pb（HSO4）2与Ba（HSO4）2而溶解,用水稀释后得到松散的PbSO4与BaSO4,使HAc-NaAc的抽取率大大提高,当m（Pb）：m（Ba）=3：1甚至2：1时,得到满意的测定结果。     

析相微萃取-分光光度法测定化妆品中痕量铅

采用1 -(2-吡啶偶氮)-2-萘酚(PAN)为螯合剂,四氯化碳为萃取剂,丙酮为助溶剂,建立了析相微萃取-分光光度法测定化妆品中痕量铅的分析方法,并对影响络合反应和相分离的各种条件进行了优化.优化后的条件为:当水相体积为21.5 mL时,四氯化碳为2.0 mL,丙酮为1.5 mL,萃取时间为10 min.铅的质量浓度在0.20～13 μg/mL范围内与吸光度呈线性关系,相关系数为0.999 81,方法的检出限为0.01 μg/mL,对铅的质量浓度为1.0 μg/mL的样品溶液进行7次平行测定,相对标准偏差为1.98％.该方法用于化妆品中铅的测定,回收率为96.4％ ～ 103.4％.     

Study on the fate of As,Hg and Pb in Yima coal via sub-critical water extraction

Arsenic, lead and mercury are the major hazardous trace elements contained in coals. During coal combustion these trace elements release and emit to the atmosphere and cause harmful effects to the human beings and the environment. This paper is to study the fate of arsenic, lead and mercury in Chinese Yima coal by sub-critical water treatment. The experiments were performed in a semi-continuous apparatus. Demineralization, float-sink experiment and sequential chemical extraction were carried out in order to examine the transformation of occurrence mode of the three elements. The results show that with increasing temperature and residence time, the removal of As, Pb and Hg increases. At 410 °C, 15 MPa, 30 min, with water flow rate of 450 ml/h, the removal of mercury and arsenic is about 100% and 57%, respectively. It is difficult to remove lead by sub-critical water extraction. Arsenic and lead in Yima coal are associated not only with pyrite, but also with monosulfides and sulfates, other minerals including silicates, aluminum silicates etc. and organic matters. Mercury is mainly associated with pyrite (about 75%) by adsorption, and is also associated with other minerals such as clays, silicates, aluminum silicates etc. During sub-critical water treatment, arsenic associated with carbonates, sulfates and monosulfide, pyrite and other minerals all decrease, and that associated with organic matters increase. Only a little lead in Yima coal is removed by this process. Mercury associated with pyrite and other minerals decreases, and that associated with sulfates and monosulfides disappears after sub-critical water extraction.     

浊点萃取-原子吸收法测定水中微量的铅

基于5-Br-PADAP与铅形成稳定的螯合物能被TritonX-114浊点萃取的事实,建立了浊点萃取-原子吸收法测定水中微量的铅的新方法。铅的浓度在0~30μg/mL内呈线性,检测限为1.7 ng/mL;相对标准偏差（n=11）为2.7%,加标回收率为97.5%~102.5%。     

响应面法优化水/醇处理后汽爆玉米秸秆酶解

为了提高水/醇处理后汽爆玉米秸秆的酶解还原糖产率,对其酶解条件进行了优化。通过响应面优化法确定了底物质量浓度为53.28 g/L,纤维素酶用量为53.32 FPU/g,酶解时间为60.45 h时,还原糖产率可达672.36mg/g,与秸秆物料及汽爆后物料相比,酶解还原糖产率分别提高了170.46%和28.97%。化学组分及结构形貌分析表明,汽爆水/醇处理后物料纤维素含量显著增加,物料相对结晶度增高,其结构更有利于纤维素酶分子的吸附。     

响应面法优化水/醇处理后汽爆玉米秸秆酶解的研究

为了提高水/醇处理后汽爆玉米秸秆的酶解还原糖产率,对其酶解条件进行了优化。通过响应面优化法确定了底物浓度为53.28g/L,纤维素酶用量为53.32FPU/g,酶解时间为60.45h时,还原糖产率可达672.36mg/g,与秸秆物料及汽爆后物料相比,酶解还原糖产率分别提高了179.21%和37.29%。化学组分及结构形貌分析表明：水/醇处理后物料纤维素含量显著增加,X射线衍射(XRD)和扫描电镜(SEM)结果表明经过水/醇处理后物料相对结晶度增高,但结构更有利于纤维素酶分子的吸附。