邻菲罗啉分光光度法测定铁

本文就邻菲罗啉分光光度法测定铁的入射光波长，显色时间，显色剂用量和显色反应酸度进行了选择试验，并用选定的条件对水泥生料中铁进行测定。     

重铬酸钾滴定法测定铁矿石中亚铁含量方法的改进

建立了以邻菲罗啉(Phen)、氢氟酸(HF)和硫酸(H_2SO_4)为溶剂溶解试样,用重铬酸钾滴定法测定铁矿中亚铁含量的新方法。在强酸(H_2SO_4)介质中,Fe~(2+)与邻菲罗啉和氟离子形成稳定的络合物,有效地防止了亚铁离子的氧化。在硼酸、硫磷混酸溶液中,以重铬酸钾溶液滴定,并对溶样过程以及滴定过程中的一些条件进行了优化。方法用于铁矿中氧化亚铁的测定,经过国家标准样品以及单位管理样品分析数据对比,方法的重现性较好,相对标准偏差(RSD)<1%,方法无需在铂金坩埚进行熔样,具有准确度高、重现性好、简单、快速、经济等优点,在实际应用中得到满意的结果。     

光度法测定水中微量铁的探讨

提出一种新的非有机溶剂萃取光度法测定水中微量铁，使其分离、富集、测定一次完成。与一般溶液光度法比，提高了测定选择性和灵敏度；与有机溶剂萃取光度法比，具有不挥发、无毒、廉价、操作简便等特点。     

氧化锆制品中微量铁的测定

氧化锆制品中微量铁的测定魏琴，杜斌，罗川南（山东建材学院应化系）氧化锆制品是一种具有优良高温性能和化学性能的材料，它被广泛用于建材、冶金、机械、化工等行业。氧化锆制品中，杂质铁的含量直接影响到制品的性能，因此需建立一种快速、灵敏、准确地检测杂质铁含量...     

磷灰石中钙含量测定方法的探讨

在强碱条件下因为PO^3-4与Ca^2 结合 生成难溶的Ca3(PO4）2,用经典方法测不出磷灰石中的钙含量。本文 提出加入过量EDTA络合全部的钙,再用CaO标准溶液测定过量的EDTA,测得准确的CaO含量。     

黄钠铁矾中铁的测定

准确快速测定黄钠铁矾中铁的含量有利于控制铁湿法冶金的流程。采用氢氧化钠溶液分解试样,盐酸(1+9)溶解滤渣,蒸发除过量酸,氨水沉淀分离铜、镍、钴等元素,再用稀盐酸溶解沉淀。在盐酸介质中,SnCl_2将大部分Fe(Ⅲ)还原为Fe(Ⅱ),钨酸钠为指示剂,用TiCl_3还原呈钨蓝色,重铬酸钾滴定至蓝色褪去。再以二苯胺磺酸钠为指示剂,重铬酸钾标准溶液滴定测定样品中铁的含量。实验表明,黄钠铁矾中共存干扰元素绝大部分被分离,同时与酸溶解法进行比较,测定数据一致,相对标准偏差(n=9)小于0.1%。     

F3（Ⅲ）—SCH—Tween—20体系分光光度法测定矿石中微量铁

对矿石中微量铁引进测定时，将表面活性剂吐温引入Ｆｅ（Ⅲ）－ＳＣＮＮ－二体系之中达到了增敏、增稳目的，测定结果满意。     

Phosphorus removal from wastewater by mineral apatite

Natural apatite has emerged as potentially effective for phosphorus (P) removal from wastewater. The retention capacity of apatite is attributed to a lower activation energy barrier required to form hydroxyapatite (HAP) by crystallization. The aim of our study was to test the P removal potential of four apatites found in North America. Minerals were collected from two geologically different formations: sedimentary apatites from Florida and igneous apatites from Quebec. A granular size ranging from 2.5 to 10mm to prevent clogging in wastewater applications was used. Isotherms (24 and 96 h) were drawn after batch tests using the Langmuir model which indicated that sedimentary apatites presented a higher P-affinity (K(L)=0.009 L/g) than igneous apatites (K(L) approximately 0.004 L/g). The higher density of igneous material probably explained this difference. P-retention capacities were determined to be around 0.3mg P/g apatite (24 h). A 30 mg P/L synthetic effluent was fed during 39 days to four lab-scale columns. A mixture of sedimentary material (apatite and limestone 50-50%, w/w) showed a complete P-retention during 15 days which then declined to 65% until the end of the 39 days lab scale test period. A limitation in calcium may have limited nucleation processes. The same mixture used in a field scale test showed 60% P-retention from a secondary effluent (30 mg COD/L, 10 mg Pt/L) during 65 days without clogging.     

蛤蜊中微量元素含量的测定

用高压罐硝化样品,以正交试验原理,借助方差分析,利用ICP-AES法测定蛤蜊中Co、Mg、Zn、Fe、Ca、Sr等15种微量元素的含量,方法回收率在96.50%¹02.50%之间,相对标准偏差小于2.57%。ICP-AES法具有灵敏度高、简单,快捷等优点,且多元素同时测定,更适合蛤蜊中金属与非金属元素的分析测定。通过实验:蛤蜊中含有丰富的Mg、Zn、Fe、Ca、K、P,还含有Se、Ge、Sr、Mn等微量元素对人体健康极其有益,是营养价值很高的海产品。但近些年,海水被环境造成一定程度的污染,食用时应加以注意。     

催化动力光度比色法测定痕量银

ＧＢ５７４９—８５《生活饮用水卫生标准》对饮用水中银的含量做出了规定,并在ＧＢ５７５０—８５《生活饮用水标准检验法》中提出了对银的检验法即原子吸收分光光度法。该法费时、费力,操作复杂,检测成本较高且银的检出率很低。现推荐采用催化动力———光度比色法进...     

石墨炉原子吸收光谱法测定水中痕量铊

建立了直接测定水中铊的无灰化石墨炉原子吸收光谱法.样品经过前处理浓缩后,在优化的仪器工作参数下,该方法对铊的检出限为0.04μg/L,回收率在80%～110%之间,相对标准偏差(n=6)为1.3%～4.56%.所建立的分析方法准确、快速,适用于地表水、生活饮用水、矿泉水中痕量铊的检测,具有一定的推广应用价值.     

Determination of selected trace elements in herbs and their infusions

The following macro- and microelements were determined in the leaf of peppermint (Mentha piperitae folium) and nettle (Urticae folium) (as tea bags) and in their infusions: As, Ba, Ca, Cd, Co, Cr, Cu, Fe, I, Li, Mg, Mn, Ni, Pb, Se, Sn, Sr, Ti, V and Zn. The determinations were performed using inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS). From all the determined microelements the highest content found was that of iron, 244 and 107 mg/kg in the leaf of peppermint and nettle, respectively. However, the lowest content found was that of cobalt, 0.10 and 0.08 mg/kg for the leaf of mint and nettle, respectively. The most readily water eluting elements were strontium, selenium and iodine, the most difficult ones - barium and iron.     

原子荧光法测定饮用水中痕量铅

采用原子荧光法测定生活饮用水中铅的含量。试验结果表明，该方法的回归方程为y=37．00x＋28．25，r=0．999，在0．001～0．025mg／L范围内有良好的线性关系。采用该方法测定水中痕量铅能获得理想的结果，可在生活饮用水检测中推广运用。     

Determination of trace amounts of iodide-ions in water using pulse inverse chronopotentiometry

A technique for metering the microconcentrations of iodide–ions in water using the pulse inverse chronopotentiometry method has been developed. This technique features a sufficient reproducibility and accuracy in terms of metrological certification criteria.     

固相萃取光度法测定饮用水中痕量铬

基于固相萃取分离技术结合分光光度法,建立了一种测定饮用水中Cr（Ⅵ）的分析方法。在强酸性介质中,Cr（Ⅵ）与二苯碳酰二肼反应生成Cr（Ⅲ）-二苯偶氮碳酰肼有色络合物,该有色络合物被Sep—PakC18固相萃取小柱富集,用乙醇和硫酸混合液洗脱后分光光度法测定,固相萃取柱不被破坏且可重新处理使用。同时研究了固相萃取条件,讨论了共存离子的干扰及消除。将该方法用于测定饮用水中痕量铬,相对标准偏差RSD为3．5％～5．1％（n=5）,标准加入回收率为99％-105％。     

A study of the reaction mechanisms of the degradation of 2,4-dichlorophenoxyacetic acid by oxalate-mediated photooxidation

The oxidation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) by FeII/H2O2/UV (FHU) and ferrous-oxalate/H2O2/UV (FOHU) processes was investigated and compared. The initial decay rate and the overall removal percentage were used as the performance indexes. To extensively explore the associated processes, the intermediates and the end products were also examined and compared. The results showed that the degradation of 2,4-D by FHU is slower than that of FOHU. The involvement of ferrous-oxalate in the reaction can greatly improve the initial decay rate of 2,4-D because of the higher light sensitivity of the organometallic complexes. The total removal of 2,4-D and its corresponding intermediates was found to be strongly dependent on the initial hydrogen peroxide concentration; an excessively low initial [H2O2] will terminate the process due to the deficiency of hydroxyl radicals in the solution. All of the major primary intermediates (2,4-dichlorophenol, 2-chloro-4-hydroxyphenoxyacetic acid, 4-chloro-2-hydroxyphenoxyacetic acid, 5-hydroxy-2,4-dichlorophenoxyacetic acid and 6-hydroxy-2,4-dichlorophenoxyacetic acid) have been identified and confirmed by LC-MS. A reaction mechanism was proposed for FHU and FOHU and verified by the evidence presented in this study.     

Adsorption of trace metals on aluminium oxide: A simulation of processes in freshwater systems by close approximation to natural conditions

The interaction of the trace metals Cu, Co, Zn, Ni, Pb and Cd with aluminium hydroxide precipitated in-situ from homogeneous solution was studied. Using total concentrations of 10⁻⁴ M Al, 10⁻⁷ M Zn, Cu, Co, Ni and 10⁻⁸ M Pb and Cd a removal of Zn, Cu, Pb, Cd from solution occurred together with Al, while Co and Ni concentrations in solution remained unchanged. The binding of Cu, Pb and Zn, Cd is in agreement with the effect predicted by using published (resp. evaluated for Zn and Cd), values for stability constants of surface complexes on preformed Al₂O₃-suspension. The different behaviour of these elements and of Co and Ni is expected from the hydrolysis and adsorption tendencies. The experimental conditions correspond to natural conditions in lake waters, where due to the pH-dependent solubility of aluminium hydroxide, in-situ precipitation may occur and cause the scavenging of trace elements.