The measurement uncertainty was estimated for the determination of calcium and magnesium in milk using microwave plasma torch atomic emission spectrometry (MPT-AES) and the uncertainty parameters were discussed and compared in detail. The results show that the "whole method" performance parameters, such as precision and recovery, and sampling are the three main contributors to uncertainty. In addition, the content of calibration solution is the main contributor to measurement uncertainty in the determination of magnesium. When coverage factor k=2 and confidence level approximately 95%, the expanded uncertainties were determined as 18.6 and 3.2 mg/L for Ca and Mg, respectively.

AMPS, diethanolamine, and calium nitrate as materials of early-strength accelerator were prepared and characterized. Orthogonal experiment was utilized to optimize optimum content of early-strength accelerator. The samples were characterized with powder X-ray diffraction (XRD) and SEM. It is shown that when the weight of 5% early agents were introduced, the 1, 3 and 7 d of cement strength improved by 15.2%、14.3%、16.7%, respectively, which is also a further development in the high temperature.

The AS fluid loss additive was formulated with sodium lignosulfonate and the copolymers obtained by radical polymerization with AMPS and AM as raw material. Orthogonal tests were designed for optimizing the synthetic process of the fluid loss additive AS, and the performance of this fluid loss additive was systematically evaluated. API filtration in saturated salt solution at 150 ℃ is 96 mL; API filtration can be controlled within 50 mL when adding AS between 3% and 8% (weight percentage) at 120 ℃; Meanwhile AS has good compatibility with other additives. Sodium bicarbonate was used to adjust the PH and discharge oxygen of device used in the synthesis process. No nitrogen was needed as protective gas, which simplified the synthesis process. The sodium lignosulfonate derives from the wastewater of paper mill, so it not only reduces the cost but also protects the environment.

The thickening agent of graft copolymer was synthesized by carboxymethyl starch (CMS) and acrylamide (AM) under the condition of initiator. The optimum synthesis conditions were investigated by orthogonal experiment design. The structure of the product which was obtained under the best reaction conditions was characterized by FT-IR, and the salt sensitivity and temperature stability, shear stability and anti-ageing of the graft copolymer solution in different slurry were measured by rotational viscometer. The results show that the viscosity can reach 280 mPa·s under the reaction conditions as follows: the reaction temperature 60 ℃, the reaction time 7 h, the mass ratio of CMS to AM 1∶6 and the initiator addition amount 0.9%. The CMS-AM graft copolymer in different slurry shows excellent the salt sensitivity and temperature stability, shear stability and anti-ageing, which can satisfy the needs of oil field fracturing fluid for thickening agent.

The method for the determination of copper, zinc, manganese, iron, magnesium, calcium in wild pine tea by microwave plasma torch-atomic emission spectrometry (MPT-AES) was developed. The effect of nitric acid concentration in the sample solution and co-ionized elements on the emission intensity of copper, zinc, manganese, iron, magnesium and calcium was investigated in detail. The experimental conditions were optimized and showed that the detection limits of metal Cu, Zn, Mn, Fe, Mg and Ca are 3.6, 7.7, 6.1, 14.1, 0.5 and 0.9 ng/mL, respectively, and the RSD of the method is between 1.05%～6.46%, the recoveries are 97.25%～103.37%. This demonstrated that the proposed method is simple, accuracy and efficient, providing a well-established analytical method．

 

Flavonoids were extracted from codonopsis pilosula with microwave-assisted method, and its content was determined by spectrophotograpy. Two methods with NaNO2-Al(NO3)3 or AlCl3 as the chromogenic agent were performed and the precision, stability, reproducibility and recovery ratio of the two methods were studied. The results show that the AlCl3 colorimetric determination of flavonoids in codonopsis pilosula was simple, convenient, accurate and reliable as compared with the NaNO2-Al(NO3)3 colorimetric determination method.

 

Ordinary alloy steel samples were digested in a microwave digestion system. The parameters of microwave digestion (including system of acid, time, power, and pressure) were optimized. Extraction method was used to eliminate the interference of Cu、Fe、Mn ion on Ni from the ordinary alloy steel samples. The nickel content in the samples was determined by ordinary pressure spectroscopy method. The relative error of microwave digestion is less than 1.67% and the RSD(n=5) is less than 1.24%. It is less than general method that is relative error of 2.67% and RSD（n=5）of 3.72%.

The cucumber seed oil was obtained by Soxhlet extraction with the seed as the raw material. Soxhlet extraction of oils from cucumber-seed was studied with single factor test, and the yield of cucumber-seed oils was the evaluation index. The influences of extracting solvent, extracting temperature, extracting time, the rate of raw material , and solvent on the yield of cucumber-seed oils were investigated respectively. The optimal conditions of Soxhlet method were obtained: extracting temperature is 68.5 ℃, extracting time is 8 h, the mass concentration of cucumber-seed oil is 0.071 g/mL, optimal extracting solvent is n-hexane. The oil yield reaches 40.38% under the optimal conditions.

Microwave plasma torch is used as exaction power, and Argon is used as work gas. Contents of copper and iron in gasoline were determined by microwave plasma torch atomic emission spectrometry (MPT-AES) with pneumatic nebulization sample introduction system. The influence of microwave power, support gas flow rate, work gas flow rate, oxygen shielded gas on the contents of copper and iron were discussed and optimized. The experimental results show that the detection limits of copper and iron are 5.3 and 22.1 μg/L respectively; RSD of the method is less than 2.83%; the linear ranges of copper and iron are 0.05～60 and 0.1～100 mg/L respectively; the recoveries of sample are in the range of 95.1％～103.5％. The method has many features,such as high sensitivity, rapidity, less sample quantity, low maintenance cost and accurate.

The methyl methacrylate (MMA) was synthesized by precision microwave organic synthesis system and its single-mode focusing microwave radiation technology, synchronized Pneumatic gas cooling technology. In the experiment, 2-methyl acrylate and methyl alcohol were used as materials, sulphuric acid as a catalyst for esterification, and hydroquinone as a polymerization inhibitor. Under Discover precision microwave organic synthesis system standard mode, the mol ratio of reaction, the reaction power, the reaction time, and other factors were investigated. The experimental results show that the optimal conditions of microwave heating are as follows: The reaction temperature 70 ℃, the ratio of 2-methyl acrylate and methyl alcohol 1∶2, the power 100 W, the reaction time 30 min, the yield 88%.

Acrylic ester emulsion was polymerized in the Discover Organic Synthesizing System with methyl methacrylate(MMA) and butyl acrylate(BA)as polymerizing monomer, potassium peroxydisulfate (KPS) as evocating agent, and sodium dodecyl sulfate (SDS) as emulsifier. In the process the mass of KPS, SDS, MMA and BA, as well as reaction temperature were separately inspected in detail so that the influence of microwave power on emulsion polymerization and a kinetic study of microwave polymerization had been conducted. The property and structure of polymerization emulsion was determined and characterized with thermogravimetrie analyzer(TGA)，differential scanning calorimeter(DSC) and FT-IR. The results of the experiments show that microwave power is 60 W, the mass of KPS, SDS, MMA and BA is 0.06 g, 0.27 g , 0.3 g and 0.3 g respectively; reaction temperature is 343 K; the activation energy of reaction is Ea=96.957 1 kJ/mol; the kinetics equation, Rp=k\[n(KPS)\]1.107 9\[n(SDS)\]0.616 4\[n(MMA)\]1.205 9\[n(BA)\]-0.228 is established for single mode focusing microwave irradiation emulsion polymerization.

The analytical methods, using microwave plasma torch as excitation light source, argon as supporting gas and peneumatic nebulization sampling system, for Cu and Fe metal elements in cucumber-seed oils by Microwave plasma torch atomic emission spectrometry (MPT-AES) was studied. The detection experimental parameters, including microwave forward power，flow rate of carrier gas and support gas, acid concentration of HNO3 and HClO4 on the detections were investigated, and coexistent ions to the emission strength of metal elements of Cu, Fe were optimized. The detection limits of mass concentration of Cu, Fe were 5.3 and 22.1 ug / L, RSD (n=6) <5%, and measured their recovery rates were 97.4% and 102.8%, and the accuracy of the method was identified by standard addition recovery. The results show that, the Cu, Fe of cucumber-seed oil of MPT-AES determination is simple, high degree of automation, low running costs, quickly and accurately. Therefore it is a well-established analytical method.

The analytical method for antimony element in nickle passivator was studied by microwave plasma torch atomic emission spectrometry (MPT-AES). Using microwave plasma torch (MPT) as excitation light source, argon as support and carrier gas, and peneumatic nebulization sampling system. Some experimental parameters, including microwave forward power, flow rate of carrier gas and support gas, oxygen shield pressure, effect of acid, coexistence ions were investigated and optimized. The detection limits was 1.9 μg/L. The recover was in the range of 99.2%～100.3%, and its RSD was 2.10％. The Linear range of the antimony elements was 0.01～100 mg/L. MPT-AES was an effective and practical method for determination of antimony in nickle passivator.