KMnO4-甲醛-茚三酮化学发光体系的研究

在甲醛存在下,KMnO4与茚三酮能够发生化学发光反应,产生很强的化学发光.据此采用流动注射技术,建立了一种利用KMnO4-甲醛-茚三酮化学发光体系测定茚三酮的方法.方法的检出限为3×10-8 g/mL;相对标准偏差为1.1%(4.0×10-6g/mL茚三酮,n=11);线性范围为1.0×10-7～2.0×10-4 g/mL.本法已用于样品中茚三酮的测定.     

流动注射化学发光法测定氯化血红素

在甲醛存在的条件下,在酸性溶液中KMnO4与氯化血红素能够发生化学发光反应,产生很强的化学发光。据此采用流动注射技术,建立了一种利用KMnO4-甲醛-氯化血红素化学发光体系测定氯化血红素的化学发光分析法。方法的检出限为6×10-8g/mL;相对标准偏差为1.8%(2.0×10-6g/mL氯化血红素,n=11);线性范围为2.0×10-7~8.0×10-6g/mL。本法用于新鲜鸡血中氯化血红素的测定,结果与标准方法测得值一致。并对化学发光反应的机理进行了探讨。     

流动注射-化学发光法测定富马酸依美斯汀

在酸性条件下,KMnO4与甲醛能够产生微弱的化学发光,而富马酸依美斯汀的存在能够大大增强该化学发光强度;结合流动注射技术,建立了测定富马酸依美斯汀的流动注射-化学发光新方法。该方法的线性范围分别为3.0×10-8～2.0×10-7g/mL,2.0×10-7～1.0×10-6g/mL和1.0×10-6～8.0×10-6g/mL。检出限为1.0×10-8g/mL,对2.0×10-6g/mL富马酸依美斯汀滴眼液平行测定11次,其相对标准偏差为1.3%。该方法已成功应用于滴眼液中富马酸依美斯汀的含量测定。     

高效液相色谱化学发光法测定血清中左羟丙哌嗪

在H2SO4介质中, KMnO4氧化左羟丙哌嗪产生化学发光, 甲醛可增敏上述化学发光, 在此基础上建立了反相高效液相色谱(RP-HPLC)分离, 柱后化学发光检测左羟丙哌嗪的新方法, 并成功应用于血清中左羟丙哌嗪的测定. 在优化的实验条件下, 该法测定左羟丙哌嗪的线性范围为1.0×10-7～1.0×10-5 g/mL, 检出限(3σ)为3×10-8 g/mL. 对2.0×10-6 g/mL的左羟丙哌嗪进行11次平行测定, 其相对标准偏差为2.3%.     

流动注射-化学发光方法测定盐酸萘甲唑林和盐酸氧甲唑林

H2SO4酸性条件下,甲醛对KMnO4-盐酸萘甲唑林(盐酸氧甲唑林)化学发光体系有较强的增敏作用,且强度与药物浓度呈良好的线性关系.据此,建立了采用KMnO4-甲醛体系测定制剂中盐酸萘甲唑林(盐酸氧甲唑林)的流动注射-化学发光分析法.在优化的实验条件下,盐酸萘甲唑林在1.0×10-8～7.0×10-6g/mL范围内呈良好的线性关系,检出限为8.69×10-9g/mL;盐酸氧甲唑林在5.0×10-8～1.0×10-5范围内呈线性关系,检出限为3.47×10-8g/mL.对浓度为1.0×10-6g/mL的盐酸萘甲唑林和盐酸氧甲唑林分别进行的11次平行测定,RSD分别为4.0%和4.1%.     

流动注射化学发光法测定盐酸氟桂利嗪

在酸性条件下,盐酸氟桂利嗪与KMnO4反应可产生弱的化学发光,甲醛的存在对这一反应的化学发光强度具有增强作用。据此,优化了化学发光反应条件,建立了测定盐酸氟桂利嗪的流动注射化学发光分析法。该方法测定盐酸氟桂利嗪的线性范围为8.0×10-7~8.0×10-5g/mL,检出限为8×10-7g/mL,对1.0×10-5g/mL盐酸氟桂利嗪标准溶液进行11次平行测定的相对标准偏差为2.2%。方法已用于盐酸氟桂利嗪胶囊中盐酸氟桂利嗪的测定。     

高锰酸钾-甲醛-扑尔敏体系化学发光的研究

在酸性介质中,KMnO4能氧化扑尔敏发生化学发光反应,甲醛的存在可使发光强度增强。据此,采用流动注射技术,建立了一种测定扑尔敏的化学发光分析法。方法的检出限为5×10-8g mL,相对标准偏差为0.7%(n=11,ρ=8×10-6g mL),线性范围为1.0×10-7～2.0×10-5g mL,该法已用于扑尔敏片剂中扑尔敏的测定。     

抗癫痫药卡马西平的流动注射化学发光分析

在酸性条件下,卡马西平对KMnO4-Na2SO3化学发光体系具有明显的增敏作用,据此建立了流动注射化学发光测定卡马西平的新方法.该发光体系中,卡马西平质量浓度在1.0×10-9～1.0×10-6 g/mL 范围内与发光强度呈良好的线性关系,检出限为2.0×10-10g/mL,对1.0×10-7 g/mL 卡马西平进行11次平行测定,其相对标准偏差为0.9%.本方法已应用于片剂中卡马西平测定,并与药典方法进行了对照.     

MnO_2纳米溶胶-抗坏血酸化学发光反应的研究

在中性条件下利用Na2S2O3还原KMnO4制备出平均粒径约40 nmMnO2溶胶。研究发现,该溶胶在酸性条件下可氧化抗坏血酸产生化学发光。基于此,结合流动注射技术,对影响化学发光反应的各种因素进行了考察,建立了测定抗坏血酸的流动注射化学发光新方法。该方法测定抗坏血酸的线性范围为2.0×10-6~1.0×10-4g/mL,检出限为4×10-7g/mL,相对标准偏差为2.1%(1.0×10-5g/mL抗坏血酸溶液,n=11)。该方法已用于片剂中抗坏血酸的测定,结果与药典方法一致。     

KMnO4-鲁米诺-香叶木素化学发光体系的研究

KMnO4-鲁米诺-香叶木素在碱性条件下有较好的发光特性,且香叶木素浓度在1.0×10-9～3.0×10-7g/mL范围内有很好的线性关系,该体系的检出限为3.7 ×10-10g/mL,对1.0×10-7 g/mL香叶木素进行11次平行测定,其RSD为1.9％.研究了体系的化学发光及紫外光谱特性,提出了发光反应可能的机...     

Influence of Potassium Metal-Support Interactions on Dendrite Growth

Combined synchrotron X-ray nanotomography imaging, cryogenic electron microscopy (cryo-EM) and modeling elucidate how potassium (K) metal-support energetics influence electrodeposit microstructure. Three model supports are employed: O-functionalized carbon cloth (potassiophilic, fully-wetted), non-functionalized cloth and Cu foil (potassiophobic, nonwetted). Nanotomography and focused ion beam (cryo-FIB) cross-sections yield complementary three-dimensional (3D) maps of cycled electrodeposits. Electrodeposit on potassiophobic support is a triphasic sponge, with fibrous dendrites covered by solid electrolyte interphase (SEI) and interspersed with nanopores (sub-10 nm to 100 nm scale). Lage cracks and voids are also a key feature. On potassiophilic support, the deposit is dense and pore-free, with uniform surface and SEI morphology. Mesoscale modeling captures the critical role of substrate-metal interaction on K metal film nucleation and growth, as well as the associated stress state.     

Cleavage of different ether bonds in butyl glycidyl ether and allyl glycidyl ether by K, K(15-crown-5)2

The kind of substituent in alkyl glycidyl ethers affects the course of their reaction with K⁻, K⁺(15-crown-5)₂. The cyclic oxirane ring is exclusively cleaved in the case of butyl glycidyl ether whereas the presence of the unsaturated allyl group in the glycidyl ether molecule unexpectedly prefers the scission of the linear ether bond. In both the systems organometallic intermediates are formed. They react with crown ether causing its ring opening. Allylpotassium formed from allyl glycidyl ether reacts also with another glycidyl ether molecule; the oxirane ring is opened in this case.     

痕量间苯二酚的 KBrO3-KBr 紫外分光光度法测定

研究了 HCl溶液中 KBrO3-KBr紫外分光光度法测定间苯二酚的条件，建立了测定痕量间苯二酚的方法。结果表明，在 0.6 mol/L HCl-4× 10-5 mol/L KBrO3-6× 10-4 mol/L KBr-6× 10-4 mol/L KI溶液中测定间苯二酚，其线性范围为 0.2～ 4.0 mg/L，表观摩尔吸光系数为 2.34× 104 L· mol-1· cm-1， Sandell灵敏度为 0.004 7 μ g/cm2。该法用于自制废水中间苯二酚的测定，获得满意结果。     

痕量碘离子的铬(Ⅵ)-碱性呫吨染料体系分光光度法测定

在过量溴化物存在下的稀磷酸介质中 ,I-被Cr(Ⅵ )氧化成I2 后与Br-结合形成[I2Br] -配阴离子 ,该配阴离子能进一步与罗丹明6G、罗丹明B、吖啶红等碱性吨染料阳离子形成离子缔合配合物。在聚乙烯醇存在下 ,缔合物体系稳定且溶液颜色有明显的变化 ,可用于I-离子的光度测定。方法具有高灵敏度 ,不同体系的摩尔吸光系数在4 .96×104 ～1 .1×105 L·mol-1·cm-1 之间 ,以罗丹明6G和罗丹明B体系灵敏度较高。碘离子质量浓度分别在0～0.8mg/L(罗丹明B和罗丹明6G体系)、0～1.0mg/L(吖啶红体系 )之间遵守比尔定律。方法具有良好的选择性 ,用于海带、黄豆和含碘药片的测定结果令人满意     

Kristallstruktur,Phasenumwandlung und Kaliumionenleitfähigkeit von Kaliumtrifluormethylsulfonat

Crystal Structure, Phase Transition, and Potassium Ion Conductivity of Potassium Trifluoromethanesulfonate According to the results of temperature dependent powder diffractometry (Guinier‐Simon‐technique) potassium trifluoromethanesulfonate is dimorphic. The phase transition occurs between –63 °C and –45 °C. The low‐temperature modification crystallizes monoclinic with a = 10.300(3) Å, b = 6.052(1) Å, c = 14.710(4) Å, β = 111.83(2)° (–120 °C) and the room‐temperature modification with a = 10.679(5) Å, b = 5.963(2) Å, c = 14.624(5) Å, β = 111.57(3)°, Z = 6, P2₁. According to single crystal structure determination, potassium trifluoromethanesulfonate consists of three different potassium‐oxygen‐coordination polyhedra, linked by sulfur atoms of the trifluoromethanesulfonate groups. This results in a channel structure with all lipophilic trifluoromethane groups pointing into these channels. By means of DSC, the transition temperature and enthalpy have been determined to be –33 °C and 0.93 ± 0.03 kJ/mol, respectively. The enthalpy of melting (237 °C) for potassium trifluoromethanesulfonate is 13.59 kJ/mol, the potassium ionic conductivity is 3.68 · 10^–6 Scm^–1 at 205 °C.     

几种钛酸钾纤维的合成及其相关性研究

本文以Ｋ＿２ＣＯ＿３和ＴｉＯ＿２为主要原料，采用混练－干燥－煅烧三步法合成出了Ｋ＿２Ｔｉ＿２Ｏ＿５、Ｋ＿２Ｔｉ＿４Ｏ＿９、Ｋ＿２Ｔｉ＿６Ｏ＿１３三种形式的钛酸钾纤维物质。测定了它们的ＸＲＤ、ＤＴＡ－ＴＧ、ＳＥＭ、ＩＣＰ、激光拉曼等有关特征数据和谱图，并对它们之间的相互关系进行了研究。     

New facts concerning the reaction of K, K(15-crown-5)2 with phenyl glycidyl ether: unexpected formation of potassium cyclopropoxide

A new mechanism of the reaction of K⁻, K⁺(15-crown-5)₂ with phenyl glycidyl ether is presented. The linear ether bond is attacked only to a small extent, if at all. As the main reaction path the oxirane bond in the β-position is cleaved, followed by the γ-elimination of potassium phenoxide and the formation of potassium cyclopropoxide. Crown ether ring opening also occurs in reactions with organometallic intermediates.     

四元体系KCl-K2SO4-CO(NH2)2-H2O有25℃时的等温溶度研究

测定了四元体系KCl－K₂SO₄－CO(NH₂)₂－H₂O及边界三元体系K₂SO－CO(NH₂)₂-H₂O在25℃时的溶度及饱和溶液密度值和折光率,绘制了相应的溶度图及相应的组成-性质图.测定并绘制了该四元体系K₂SO₄单饱区的溶度面、折光率面和密度面图.两个体系的溶度图均属于低共饱型,平衡固相为组份化合物.     

Das Mischkristallsystem K2OsCl6

The Mixed Crystal System K₂OsCl₆? K₂SnCl₆ Homogeneous mixed crystals between K₂OsCl₆ and K₂SnCl₆ have been prepared in any composition ratio by precipitation from concentrated K₂OsCl₆/K₂SnCl₆ solutions with concentrated hydrochloric acid. The lattice constants follow Vegard's rule.     

Potassium phthalimide promoted green multicomponent tandem synthesis of 2-amino-4H-chromenes and 6-amino-4H-pyran-3-carboxylates

A one-pot efficient, green, practical, and environmentally friendly multicomponent synthesis of 5-oxo-4-aryl-5,6,7,8-tetrahydro-4H-chromenes, ethyl-6-amino-4-aryl-5-cyano-2-methyl-4H-pyran-3-carboxylates as well as 2-amino-4-aryl-7-hydroxy-4H-chromene-3-carbonitriles via tandem the Knoevenagel-cyclocondensation has been described in the presence of a green, low-cost, mild, efficient, and commercially available potassium phthalimide as the organocatalyst. This technique is a safe and ecofriendly approach to the synthesis of different 4H-chromens and 4H-pyrans that offers many merits including short reaction times, high yields, straightforward work-up, and no use of hazardous organic solvents.