A method for the analysis of sucralose with electrospray LC/MS in recipient waters and in sewage effluent subjected to tertiary treatment technologies

A method for the analysis of the artificial sweetener sucralose in sewage water and recipient water was developed. Extraction and clean up was performed with solid-phase extraction utilising Oasis HLB columns. Detection was made by liquid chromatography electrospray mass spectrometry (LC/MS). The triple-quadrupole mass spectrometer was operated in multiple reaction monitoring (MRM) mode. However, ‘pseudo MRM’ was used, a technique where the two quadrupoles monitor the same m/z. The sodium adduct of sucralose was used for quantification, since lower detection limits were obtained as compared to the sucralose quasi-molecular ion in negative ion mode. The two ions with highest intensity in the chlorine isotope pattern were monitored. The reduction of matrix effects with this approach is discussed. The method limit of quantification (MLOQ) for sewage water was 0.2?µg?L^?1, whereas for recipient water MLOQ was 0.02?µg?L^?1. The method was used to analyse effluent samples from an experimental sewage treatment plant (STP) to assess the efficiency of tertiary treatment techniques for removal of sucralose. Filtration through activated carbon was shown to be efficient, while ozonation, advanced oxidation techniques and membrane bioreactors were less efficient. Analyses of receiving waters showed low dilution of sucralose emitted from the STPs.     

Comparison of Some Soft Unplasticized Cast Polyurethane Rubbers

Different types of unplasticized cast polyurethanes with hardness around 60 Shore A have been compared. The tensile properties, tear strength, resistance to hydrolysis, and swelling in solvents and water were examined. The influence of composition on the properties of cast polyurethanes prepared from a polyadipate polyol and diisocyanates, including the effect of a range of fillers, was investigated in detail. Fumed silica, fumed alumina, and carbon black significantly increased the hardness and tensile strength of the rubber, whereas kaolin and talc gave small increases. Ground silica, calcite, and rutile had no effect. No significant increases in tensile strength were obtained with silane and titanate coupling agents with a fumed silica filler. The rate of hydrolysis or extent of swelling in xylene was unchanged by fillers.     

Raney Nickel–Catalyzed Hydrogenation of Unsaturated Carboxylic Acids with Sodium Borohydride in Water

A mild, selective, and green method for the reduction of unsaturated carboxylic acids with sodium borohydride–Raney nickel (W6) system in water is reported. This method is practical and safe and avoids use of organic solvents.     

Electrochemical determination of electroinactive guests of b-cyclodextrin at a self-assembled monolayer interface

A novel determination method of electroinactive molecules by means of electrochemical technique is presented. A new self-assembled monolayer containing cyclodextrin(CD) is prepared with mono(6-o-p-tolylsulfonyl)-b-cyclodextrin. Although this derivatization process leads to a b-CD coverage of 10% of a full monolayer, this layer shows an effective host-guest response to ferrocene. The interfacial ferrocene complexation gives a response similar to that expected for a Langmuir adsorption isotherm yielding a stability constant of 4.2×104 mol-1@L and a maximum ferrocene coverage of 8.6′10-12 mol/cm2. The redox peak currents of the surface-confined ferrocene de-crease upon addition of competing b-CD guest species to the solution, such as m-toluic acid(mTA) and sodium dodecyl sulfonate(SDS). This principle has been used for the determination of the electroinactive molecules, mTA and SDS in the concentration ranges of 0.8-2.7 mmol/L and 5-100 nmol/L, respectively.     

在线电生锰(Ⅲ)流动注射化学发光法测定地塞米松磷酸钠

采用在线恒电流电解产生Mn(Ⅲ)与流动注射化学发光法相结合,基于地塞米松磷酸钠可使Mn*#-Na2SO3新体系化学发光大大加强的现象,建立了测定地塞米松磷酸钠的新分析方法.其线性范围为1×10-4～1×10-2 g/L;检出限为7×10-5 g/L;RSD为1.2%.该法成功地应用于针剂中地塞米松磷酸钠的测定.     

Über die quasi-binären Systeme NaNO2/Na2O und NaCN/Na2O. Phasendiagramme und Natrium-Ionenleitung in Na3O(NO2) und Na3O(CN)

On the Quasi-Binary Systems NaNO₂/Na₂O and NaCN/Na₂O. Phase Diagrams and Sodium Ion Conductivity of Na₃O(NO₂) and Na₃O(CN) Measurements of the electrical conductivities of Na₃O(NO₂) and Na₃O(CN) show sharp increases in conductivity at temperatures between 200° and 250°C, According to the phase diagrams of the quasi-binary systems NaNO₂/Na₂O and NaCN/Na₂O this is not an effect established by fusion. It seems to be a consequence of a “melting” of the sodium sublattice or the rotational disorder of complex anions.     

The Photocatalyzed Reduction of Aqueous Sodium Carbonate Using Nano SrFeO3

Heterogenous photocatalyzed reduction of aqueous Na2CO3 has been carried out by using nano SrFeO3 semiconductor powders.Formic acid,formaldehyde and methyl alcohol were identified as photoproducts,and were measured spectrophotometrically.The effect of the variation of different parameters such as sodium carbonate concentration,amount of photocatalyst and different light sources on the yield of photoproducts was also investigated.It shows that nano SrFeO3 has photocatalytic activity.Irradiation leads to the production of electrons in the conduction band of the SrFeO3 semiconductor.It is likely that the photoproduced electrons reduce CO3^2- initially to HCOO^-,and then to HCHO and CH3OH.     

N-芳亚甲基-2-丙烯-1-胺与甲醇钠的反应

研究了N-芳亚甲基-2-丙烯-1-胺（1）与甲醇钠的反应，当甲醇钠过量，反应 时间足够长时，生成的主要产物是N-芳亚甲基-1-甲氧基-丙胺（2）。     

等温滴定量热法和荧光滴定法研究十二烷基硫酸钠与纤维素酶的结合

用等温滴定量热法和荧光滴定法研究了阴离子型去垢剂十二烷基硫酸钠（SDS ）与绿色木霉纤维素酶相互作用的热力学，SDS结合纤维素酶的亲和力较弱，为较 小的放热反应，并伴随着一定程度的熵增，为焓和熵共同驱动的反应，而且存在着 显著的焓-熵补偿作用。该结合过程的摩尔恒压热容为较大的负值（-186 J·mol~ (-1)·K~(-1)），这表明疏水相互作用是形成复合物的主要作用力，SDS的加入使 纤维素酶的内源荧光发生猝灭，同时导致该蛋白荧光光谱最大发射峰位的红移和酶 活力的部分丧失，这表明SDS与纤维素酶的相互作用既包含结合反应也包含SDS诱导 该蛋白部分去折叠的过程。