光度法快速测定不锈钢中的铬、镍、钼、钛、锰

试样用等体积硝酸和盐酸混合酸溶解,用高氯酸将Cr(Ⅲ)氧化为Cr(Ⅵ),用定量Fe(Ⅱ)将Cr(Ⅵ)定量还原为Cr(Ⅲ),用铬酸"剩余光度法"测定铬,丁二酮肟光度法测定镍,硫氰酸盐光度法测定钼,变色酸(1,8-二羟基萘-3,6-二磺酸)光度法测定钛,高锰酸光度法测定锰。测定结果与标准值基本一致,铬、镍、钼、钛、锰测定结果的相对标准偏差分别为0.2%、0.3%、1.5%、2.0%、2.0%。     

Determination of benomyl, diphenyl, o-phenylphenol, thiabendazole, chlorpyrifos, methidathion, and methyl parathion in oranges by solid-phase extraction, liquid chromatography, and gas chromatography

A simple and rapid method was developed for determination of benomyl, diphenyl (DP), o-phenylphenol (OPP), thiabendazole (TBZ), chlorpyrifos, methidathion, and methyl parathion in whole oranges. These compounds were extracted from a mixture of samples and anhydrous sodium acetate with ethyl acetate. The ethyl acetate extract was concentrated and cleaned up by passing through tandem solid-phase extraction columns consisting of anion-exchange and primary/secondary amine bonded silica. The eluate was concentrated and volume was adjusted with methanol for subsequent liquid chromatography (LC) and gas chromatography (GC). Benomyl (as methyl-2-benzimidazole carbamate, MBC), DP, OPP, and TBZ residues were determined by LC with fluorescence detection. Recoveries at 3 fortified levels (0.1, 1, and 10 micrograms/g) ranged from 63.9 to 97.4%, with coefficients of variation (CVs) of 1.6 to 15.5%. Limits of detection (LODs) were 0.01 microgram/g for DP, OPP, TBZ and 0.05 microgram/g for benomyl. Chlorpyrifos, methidathion, and methyl parathion residues were determined by GC with flame photometric detection. Recoveries ranged from 90.4 to 97.0%, with CVs of 2.1 to 5.9%. LODs were 0.005 microgram/g for chlorpyrifos and methyl parathion, and 0.01 microgram/g for methidathion.     

Determination of zirconium, barium, lanthanum, aluminium, sodium, hafnium and fluorine in fluorozirconate glasses

Summary A procedure is described for the determination of the cationic and anionic components in fluorozirconate glasses. Zirconium, barium, aluminium, lanthanum, sodium and hafnium were determined by inductively coupled plasma atomic emission spectrometry (ICP/AES) after dissolution of the sample with an acid mixture in a microwave oven. The fluorine content was evaluated with two different techniques, namely potentiometry with a fluoride ion-selective electrode (FISE) and ion chromatography (IC). In this case the sample was solubilized by fusion with sodium carbonate.     

Synthesis,characterization, DNA binding,antibacterial, and antioxidant activity of new bis-phthalimides

New bis-phthalimides were synthesized by 2: 1 condensation of phthalic anhydride and tetrachlorophthalic anhydride with 1,2,4-triazole-3,5-diamine, pyridine-2,6-diamine, and 4-hydroxypyrimidine- 2,6-diamine. The synthesized compounds were characterized by elemental analyses and IR, ¹H NMR, and mass spectra. Their interaction with calf thymus DNA (ct-DNA) was studied by UV-Vis spectrophotometry, cyclic voltammetry, and viscosity measurements, which revealed intercalative mode of binding to ct-DNA. Antibacterial activity of the synthesized compounds against Escherichia coli and Streptococcus mutans was assessed in vitro by the agar well diffusion method. The antioxidant activity of these compounds was estimated by DPPH assay.     

ICP-AES法同时测定锰矿石中铁、铝、钛、钙、镁、磷、钡、铅的含量

锰矿石样品用HNO3-HF-HClO4酸溶除硅后,对采用ICP-AES法测定其中的铁、铝、钛、钙、镁、磷时,同时测定钡、铅的相关条件进行了试验。主要对酸溶样能否分解重晶石或天青石等含钡矿物进行了探讨,测定了3个国家级标准样品。测定结果与标准值吻合。用标准加入法测得的钡和铅的回收率分别为96．0％-100．5％,97．1％～100．0％。用该法对含钡量较高的澳大利亚锰矿进行分析,测定结果的相对标准偏差为0-82％,并将测定结果与X荧光光谱法测定结果进行了比对。     

2,4,5-三氧-1,3,2,4-二氮二磷杂环戊烷衍生物的合成和结构

本文报道了七个新的2,4,5-三氧-1,3,2,4-二氮二磷杂环戊烷衍生物的制备, 产物的结构经IR, ^1H和^31P NMR, MS以及元素分析证实, 并利用^31P NMR和GC-MS区分了化合物的顺式和反式异构体。     

3,3,6,6-四甲基-9-邻氯苯基-1,8-二氧代-3,4,5,6,7,9-六氧化氧杂蒽的合成和晶体结构

标题化合物C23H25对O3Cl是由邻氯苯甲醛与5，5-二甲基1，3-环己二酮在N，N-二甲基甲酸腹中反应而得。结构通过单晶X-射线衍射法确定，其晶体属于单科晶系，空间群=1632。晶体结构用直接法解出，使用全矩阵最小二乘法对原子参数进行修正，最后的偏离因子为R=0．054，Rw一0．063。在晶体结构中，吡喃环与苯环之间的两面角为92．43°。     

Atomic-absorption spectrophotometric determination of antimony, arsenic, bismuth, tellurium, thallium and vanadium in sewage sludge

Electrothermal atomic-absorption spectrophotometry (AAS), by use of a graphite furnace, in conjunction with sample pretreatment by homogenization, was evaluated as a rapid method for the determination of bismuth, thallium and vanadium in sewage sludge. This method was compared with use of flame, electrothermal and hydride-generation (for bismuth) AAS in conjunction with conventional acid digestion and dry-ashing pretreatments and was found to be applicable to this type of sample. Comparisons were also made between flame and hydride-generation AAS in conjunction with an acid digestion pretreatment for the determination of antimony, arsenic and tellurium in sewage sludge. The hydride-generation technique was considered the better for waste-water samples because of its greater sensitivity.     

Synthesis,characterization, processability,mechanical properties,flame retardant,and oil resistance of chlorinated acrylonitrile butadiene rubber

Novel chlorinated acrylonitrile butadiene rubber (Cl‐NBR) was prepared from NBR by the alkaline hydrolysis of chloroform by using phase‐transfer catalysis. The formation of Cl‐NBR was monitored by ¹H‐NMR, UV‐Vis, and Fourier transform infrared spectroscopic techniques. The percentage of chlorine attached to the rubber chain was estimated by Volhard method. The effect of polar groups on the structural and thermal properties of Cl‐NBR was analyzed by scanning electron microscopy, X‐ray diffraction analysis, differential scanning calorimetry, and thermogravimetric analysis studies. The flame retardant, oil resistance, cure behavior, and mechanical properties of chlorinated elastomer were also analyzed. The proton NMR revealed the attachment of chlorine in the backbone of NBR with new chemical shift values. The C‐Cl stretching of chlorinated NBR was confirmed from Fourier transform infrared. The UV spectrum also supported the formation of chlorinated unit in the NBR chain through the shifts and broadening of absorption peaks. The X‐ray diffraction analysis pattern indicated a decrease in the amorphous domain of NBR with an increase in the level of chemical modification. The increased glass transition temperature obtained from differential scanning calorimetry confirms the increased molecular rigidity of the chlorinated NBR and thermal transitions increased with increase in the level of chemical modification. The thermal stability of Cl‐NBR decreased with an increase in chlorine content. The flame and oil resistance of Cl‐NBR was greatly higher than pure NBR due to the increased polarity of modified rubber. The superior tensile strength of Cl‐NBR (4 times higher than pure NBR) and higher oil resistance find applications in pump diaphragms, aircraft hoses, oil‐lined tubing, and gaskets materials with the excellent flame resistant property.     

ICP-AES法同时测定玻璃组份中的Ca、Mg、Ti、Fe、Pb、Cd、Al、Si、B、Zn、Cu元素

建立了一种用电感耦合等离子发射光谱(ICP-AES)法测定玻璃成份的简便、快速、准确、精密度好的方法．研究了样品的处理、标准样品的配制、谱线干扰等问题,并采用和基体匹配的方法消除基体的影响,进行了标准样品的分析、对照、精密度等试验,均取得了满意的结果．     

Copper adsorption and Si, Al, Ca, Mg, and Na release from clinoptilolite

Copper adsorption onto clinoptilolite (natural zeolite), Al/Si dissolution, and Mg, Ca, and Na release from the substrate were the subjects of the investigation described here. Experimental variables were Cu and electrolyte concentrations and solution pH. Copper adsorption was found to increase with increased pH and with decreased electrolyte concentration. Large amounts of K were also adsorbed from electrolyte. Since solution pH was assumed as a variable, the effects of [H(+)] differentiation on Cu adsorption and on Al/Si dissolution were also examined. Al dissolution was affected mainly by electrolyte concentration, whereas Si dissolution was affected mainly by adsorbed Cu amount. It was assumed that the release of Mg, Ca, and Na occurs through ion-exchange reactions with solution K(+), because their release is affected more by electrolyte concentration than by adsorbed Cu. From the study of FTIR spectra for various samples used in the present investigation, we observed that the removal of framework Si/Al shifts the band which was attributed to O-T-O stretching vibration toward higher frequency. Significant changes were observed for the bands assigned to Si-OH-Al bridges and to monomeric and polymeric hydrogen bonds at the region between 3650 and 3200 cm(-1). It is proposed that the Cu species caused the destruction of H-bonded structures, whereas K adsorbed species were located at exchangeable sites after an ion-exchange process between K and Ca, Mg, and Na from the zeolite's surface. An expansion of the zeolite framework was detected from XRD patterns under acid conditions.     

电感耦合等离子体发射光谱法测定REACH法规涉及产品中铅、铬、钴、砷、锡、铝、锆、钼和硼

采用电感耦合等离子体原子发射光谱法对REACH法规涉及产品中铅、铬、钴、砷、锡、铝、锆、钼和硼的含量进行测定。0.2g样品经微波消解处理,聚合物材质试样以8mL硝酸和2mL过氧化氢为消解试剂;无机非金属材质试样以6mL硝酸、2mL过氧化氢和2mL氢氟酸为消解试剂。各元素的方法检出限均低于15mg·kg-1。方法的加标回收率在82.4%～108%之间,测定值的相对标准偏差(n=7)在3%～6%之间。     

STUDY ON POLYMERIZATION MECHANISM OF 3, 9,-DIALLYL-3, 9, -DIBENZYL-1, 5, 7, 11-TETRAOXASPIRO [5, 5] UNDECANE

A new monomer, 3,9-diallyl-3, 9-dibenzyl-1, 5,7,11 - tetraoxa- spiro [5,5] undecane (6) was prepared by the reaction of 2- allyl- 2' - benzyl- propanediol - 1.3 with dibutyltin oxide, and then treated with CS_2. Monomer 4 could be initiated by cationic initiators to give a viscous polymer (white powder in the case of polymerization at 0℃). Upon the NMR and IR spectra of the obtained polymer, the components and their relative amount were estimated. The polymerization mechanism was discussed.     

Determination of trace amounts of cadmium, cobalt, chromium, iron, molybdenum, nickel, selenium, titanium, vanadium and zinc in blood and milk by neutron activation analysis

The concentrations of Cd, Co, Cr, Fe, Mo, Ni, Se, Ti, V and Zn in biological fluids, human blood serum and market milk were determined by neutron activation analysis, with enrichment by coprecipitation. The pre-concentration of these trace elements was accomplished by converting the dissolved trace metal ions into their pyrrolidinedithiocarbamate (1-pyrrolidinecarbodithioate) chelates, followed by coprecipitation with a metal carrier such as Ni, Pb or Bi. The coprecipitation was carried out prior to irradiation for the short-lived nuclides (V, Ti and Se) and after irradiation for the other elements. The validity of the method was checked using certified biological reference materials; the concentrations of trace elements found by the proposed method agreed well with the published certified data. The limits of detection for Cd, Co, Cr, Fe, Mo, Ni, Se (obtained through the long-lived isotope 75Se) and Zn under the present experimental conditions were found to be 5, 5, 10, 520, 5, 70, 10 and 150 ng, respectively, for 5 ml of biological liquor. The limits of detection for Ti and V obtained (through their short-lived radionuclides 51Ti and 52V, respectively) were found to be 180 and 1.4 ng, respectively, for 50 ml of market milk, or 70 and 0.7 ng for 1 ml of blood serum.     

Charm Safe-Level beta-Lactam Test for amoxicillin, ampicillin, ceftiofur, cephapirin, and penicillin G in raw commingled milk

The Charm Safe-Level beta-Lactam Test was evaluated by a U.S. Food and Drug Administration (FDA) test protocol administered by the AOAC-Research Institute. The sensitivity and selectivity of the test were evaluated with >800 negative raw commingled and drug-fortified milk samples by the manufacturer and an independent laboratory. Probit analysis by the independent laboratory determined the following 90% positive levels with 95% confidence: amoxicillin, 5.6 ppb; ampicillin, 8.5 ppb; cephapirin, 13.7 ppb; ceftiofur, 46.2 ppb; and penicillin G, 3.6 ppb. These values were within a range of +/- 20% of the manufacturer's data. Selection of negative samples met confidence specifications. Ruggedness parameters were studied and defined, and the stability of frozen milk was verified. There were no interferences from somatic cells (1,000,000 somatic cell count/mL) or bacteria (300,000 colony-forming units/mL), or from 27 other non-beta-lactam animal drugs. Test performance with raw milk samples containing incurred penicillin, ampicillin, and amoxicillin was consistent with the dose responses determined with fortified milk samples. Incurred cephalosporin in raw milk samples was detected at lower levels than was cephalosporin in fortified milk samples, presumably because of the presence of metabolite, as verified by other test methods. Quality control data support consistency in manufacture between batches and the stability of refrigerated test reagents for up to 1 year. Successful fulfillment of these criteria led to FDA certification of the test when used with a reader in U.S. milk testing programs.     

微波辐射下4-(4-羟基-3-甲氧基)苯基-3,3,6,6-四甲基-1,8-二氧代1,2,3,4,5,6,7,8,9,10-十氢吖啶的合成和晶体结构

标题化合物C24H29NO4?1/2C2H5OH稨2O)由香兰素、5,5-二甲基-1,3-环己二酮、醋酸铵在微波辐射下干反应并经95%乙醇重结晶而得C24H29NO4穀2(C2H5OH稨2O)晶体。结构通过单晶X-射线衍射法确定,其晶体属单斜晶系,空间群P21/n, a = 9.810(2), b = 14.516(3), c = 17.008(3) ? b = 101.03(2), V = 2377.2(8) ?, Z = 4, Mr = 427.52, Dc = 1.195 g/cm3 , m(MoKa) = 0.082 mm-1, F(000) = 920。晶体结构用直接法解出,经全矩阵最小二乘法对原子参数进行修正,最终的偏离因子为R = 0.0406, wR = 0.0892。X-射线衍射分析结果表明,吡啶环和与之稠合的2个六员环均为信封式构象。     

2, 3, 4, 5, 6-五苯基苯甲醛的新合成途径

从四苯基环戊二烯酮与乙二醇缩肉桂醛通过干法在260-270℃直接加成并脱CO,接着经氧化、水解制备了2,3,4,5,6-五苯基苯甲醛,对目标产物的结构进行了^1HNMR,IR,UV-Vis和元素分析表征。在对反应中间产物进行分离、鉴定的基础上提出了该反应的可能途径。     

ICP–AES法测定铬镍不锈钢中锰、铬、镍、硅、磷、铜、钼的含量

建立电感耦合等离子体原子发射光谱(ICP–AES)法测定铬镍不锈钢中锰、铬、镍、硅、磷、铜、钼7种元素含量的方法。试样用盐酸与硝酸混合酸溶液溶解,采用溶解国家标准样品的方法制备校准曲线溶液,确定了元素最佳分析谱线。各元素的含量在其测试范围内与原子发射强度呈良好的线性关系,线性相关系数不小于0.999,7种元素的检出限在0.000 3%~0.003 0%之间。该方法应用于铬镍不锈钢标准样品的测定,测定值与认定值相符,测定值的相对标准偏差在0.12%~1.15%之间(n=8)。应用于铬镍不锈钢样品测定时,加标回收率在90%~110%之间。该方法操作简便、迅速,可满足日常铬镍不锈钢中多元素含量的检测需要。     

3,3,6,6-四甲基-4a-羟基-9-邻甲氧基苯基-1,8-二氧代-2,3,4,4a,5,6,7,8,9,9a-十氢化-1H-氧杂蒽的合成和晶体结构

标题化合物C24H30O5是由邻甲氧基苯甲醛与5，5-二甲基-1，3-环己二酮在N，N-二甲基甲酰胺中反应而得。结构通过单晶X-射线衍射法确定，其晶体属于单斜晶系，空间群C2／c，a=33．942（6），b=7273（1），c=22667（4）A，β=128．989（9）°，Mr=398．50，V=4349（1）A3，Dc=1．2179·cm-3，Z=8，μ（MoKa）=840mm－1，F（000）=1712。晶体结构用直接法解出，经用全矩阵最小二乘法对原子参数进行修正，最后的偏离因子为R=0.043，Rw=0．052。在晶体结构中，存在一个分子间氢键。     

Determination of bithionol, bromophen, nitroxynil, oxyclozanide, and tribromsalan in milk with liquid chromatography coupled with tandem mass spectrometry

LC/MS/MS was developed to determine the residues of bithionol (BTN), bromofen (BMF), nitroxynil (NTX), oxyclozanide (OCZ), and tribromsalan (TBS) in milk. Samples were extracted with ethyl acetate and cleaned up by liquid-liquid separation with acetonitrile and n-hexane. The compounds were determined by RP-LC using a C18 column with 0.1% formic acid-methanol. Mass spectral acquisition was performed in the negative mode by applying selected-reaction monitoring. The method was validated in milk spiked with these compounds at 5-600 microg/kg; average recoveries were in the range 83.8-97.1%, with RSD values of 1.4-8.0%. The interassay RSDs were less than 11%. The LODs of these compounds in milk were 0.1 microg/kg. The method was applied to 24 raw milk samples. The concentration of these compounds in all samples was lower than the Japanese maximum residue limits. The method is rapid, sensitive, and specific for monitoring residues of BTN, BMF, NTX, OCZ, and TBS in milk.