硝酸盐的大平反

Through three stories about nitrates, a storytelling technique is used to describe the main uses of nitrates today, including agricultural fertilizers, industrial explosives, and food preservatives. Nowadays, nitrate is suspected to be the main cause of carcinogenesis, but one coin has two sides; in fact, nitrates play an important role both in the ecological environment and in the human body. Therefore, the public can understand more about the applications of nitrates from this article. Through the accidental discovery of a rural couple in a wartime setting, this article describes the uses of nitrate in agriculture, antiseptic, immune systems and blood circulation system.     

Nitrate und Nitrite

Analytical and Bioanalytical Chemistry -     

Nitrate und Nitrite

Ohne Zusammenfassung     

硝酸钐/硝酸镝/硝酸铒与组氨酸液-液反应的热动力学

稀土氨基酸配合物具有消炎、杀菌、降血糖等作用犤１犦。它们的晶体结构和相化学已有报道犤２，３犦。前报犤４犦曾详细报道了稀土硝酸盐与组氨酸配合行为的溶解度图和制备与表征。但文献中未见有关该类配合反应热动力学研究的报道。本文用微量热法对硝酸钐／硝酸镝／硝酸铒与组氨酸的液－液反应进行了热动力学研究。其结果可为这类配合物的反应机理研究和制备提供必要的技术参数。１实验部分１．１试剂RE（NO３）３·６H２O（RE＝Sm，Dy，Er）按文献犤５犦的方法制备。L－α－组氨酸为B．R．（上海康达氨基酸厂）；纯度＞９９．５％…     

Nitrite und Nitrate

Ohne Zusammenfassung     

Nitrate und Nitrite

Ohne Zusammenfassung     

Nitrate in Erdalkalicarbonatgemischen

Ohne Zusammenfassung     

Nitrate Removal and Nitrate Removal Velocity in Coastal Louisiana Freshwater Wetlands

Nitrate removal and nitrate removal velocity rate were determined for Mississippi River deltaic plain forested-tupelo dominated wetland, and a floating emergent freshwater marsh. Nitrate removal rate from floodwater was 19.45 and 48.90 mg N m^?2 d^?1 for two forested-tupelo wetland sites and 48.41 and 46.98 mg N m^?2 d^?1 at two floating emergent freshwater marsh sites. The removal velocity constants (k) of NO₃-N ranged from 0.44 to 1.44 per day for the four site studies. Removal velocity of nitrate from the water column was faster in the floating emergent marsh cores than from the forested wetland course, which contained more sediment. Results demonstrated that removal velocity is an important parameter when estimating nitrate removal from floodwater. Results also demonstrated the two freshwater wetland habitats had a high capacity for processing any nitrate entering the wetlands from adjacent agriculture area. Removal was attributed to denitrification and diffusion.     

Fluorimetric Determination of Nitrate

Abstract

A sensitive fluorimetric method has been developed for the determination of nitrate based on the reduction of nitrate to nitrite with hydrazine sulfate and the subsequent determination of the nitrite formed with 2, 3-diaminonaphthalene. Solvent effect on fluorescence intensity, optimum reaction conditions, and sensitivity of the method are discussed.     

Fabrication of Redox‐Mediator Supported Potentiometric Nitrate Biosensor with Nitrate Reductase

Fabrication of a more superior nitrate potentiometric biosensor than previously achieved with NaR and NADH has been accomplished by co‐entrapment of redox mediators and NaR into polypyrrole (PPy) film during galvanostatic polymerization of pyrrole. The replacement of NADH with redox mediators such as thionin acetate (ThAc), safranin (Saf), and azure A (AzA) gave more sensitive potentiometric responses, better minimum detectable concentration, linear concentration range and response time for nitrate than possible with NADH. The co‐entrapment of ThAc, Saf, AzA and methyl viologen (MV) with NaR into PPy films also improved the Nernstian behavior of the electrode process beyond the capability of the PPy‐NaR‐NADH biosensor. Substantial reduction in volume and quantity of cofactor/mediator and, hence cost, was achieved by the replacement of NADH with a redox mediator. Only 50 μM of AzA was required to form a PPy‐NaR‐AzA biosensor which gave the most sensitive potentiometric response for nitrate, achieving a minimum detectable concentration of 10 μM, a linear concentration range of 50–5000 μM and a response time of 2–4 s.     

Solubility of Lead Nitrate in Aqueous Solutions of Nitric Acid and Zinc Nitrate

Solubility of lead nitrate in the system H₂O-Zn(NO₃)₂-HNO₃ was studied using the simplexlattice design method. The equations describing the effect of nitric acid and zinc nitrate concentrations on the content of lead nitrate in solution at 25 and 55°C were derived.     

铈硝酸盐及其硝酸铵复盐的结晶制法及性质

通过对硝酸铈、硝酸铈铵复盐的制备,叙述了硝酸铈的溶解度[1]、复盐形成等性质, 分析了结晶方式不同对铈硝酸盐及其硝酸铵复盐产品质量的差别, 指出通过改变其传统的结晶法制备工艺, 提高产品质量具有重要的现实意义.     

Calculated and Experimentally Obtained Heats of Combustion of Hydrazinium Nitrate,Monomethylhydrazinium Nitrate,and N,N‐Dimethylhydrazinium Nitrate

The heats of combustion were determined experimentally and calculated thermodynamically for the following compounds: hydrazinium nitrate, [H₂NNH₃][NO₃] ( 1 ); monomethylhydrazinium nitrate, [H₂NNH₂(CH₃)][NO₃] ( 2 ); and N, N‐dimethylhydrazinium nitrate, [H₂NNH(CH₃)₂][NO₃] ( 3 ).The agreement between the experimental and theoretical values (in parentheses) is very satisfactory: 1 , 1035 (1157); 2 , 2490 (2389); 3 , 3542 (3376) kcal kg^—1.     

金刚烷胺硝酸盐的晶体结构

报道了金刚烷胺硝酸盐(三环[3,3,1,11,7]癸烷-1-胺硝酸盐,C10H18N2O3,Mr = 214.26)的晶体结构。该晶体属于正交晶系,空间群为P212121, 晶胞参数:a = 6.380(1),b = 7.349(2),c = 22.801(5) ,V = 1069.0(4) 3,m(MoKa) = 0.098 mm-1,Z = 4,F(000) = 464,Dc =1.331 g/cm3。对于1172 (I ≥2s(I))个可观察衍射点,最终偏离因子R = 0.0310,wR = 0.0757。该晶体由金刚烷铵阳离子和硝酸根阴离子组成,金刚烷基为由椅式构象组成的一个稳定的三环结构。由于氢键作用,晶体呈二维平面无限结构。     

Bestimmung der Nitrate im Wasser

Zusammenfassung Es wird ein Verfahren der Nitratbestimmung beschrieben, das auf der Reduktion zu Nitrit mit Hydrazin in Anwesenheit von Kupferion als Katalysator beruht. Das Nitrit wird mit SulfanilsÄure--Naphtylamin photometrisch erfa\t. Die Reduktion verlÄuft beiPh 12,3 und 28 C in der Zeit von 30 min mit hohen Nitritausbeuten.Kationen, die das Entstehen von NiederschlÄgen in alkalischer Lösung verursachen würden, entfernt man durch einen Kationenaustauscher in der Natriumform. Störungen durch suspendierte oder kolloid gelöste Stoffe werden beseitigt, indem man die Lösung durch eine SÄule mit Aktivkohle filtriert, die teilweise durch n-Hexan desaktiviert worden ist.EnthÄlt die zu untersuchende Probe Nitrit, so entspricht die gemessene Extinktion der Summe Nitrat + Nitrit. Der Nitratgehalt ergibt sich in diesem Fall, indem man von der gemessenen Gesamtextinktion den auf das Nitrit entfallenden Wert abzieht. Das Verfahren liefert befriedigende Werte.Herrn Doz. Dr. J. Hrbáek möchte ich für seine Unterstützung bei der Durchführung dieser Arbeit meinen herzlichen Dank aussprechen.