Rapid Analysis of Seven Polyamines in by Using Ultra-Performance Liquid Chromatography-Triple Quadrupole Mass Spectrometry.

A fast, simple, and sensitive method for the simultaneous determination of seven polyamines in was developed based on ultra-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-3Q-MS) together with liquid phase extraction. Polyamines in insect samples were extracted with HClO solution and then were separated and detected by UPLC-3Q-MS, which was equipped with a hydrophilic interaction liquid chromatography column, within 5 min without any derivatization procedure. The method has been successfully used to detect 7 polyamines in healthy and difluormethylornithine-treated adults of with a method limit of detection and the method limit of quantitation of 24-139 pg/mg and 82-464 pg/mg, respectively, an intraday and interday relative standard deviation (RSD,  = 5) of 1.

Ecosystem health of the Beiyun River basin (Beijing, China) as evaluated by the method of combination of AHP and PCA.

Ecosystem services provided by river ecosystems rely on healthy ecosystem structure and ecological processes. The Beijing-Tianjin-Hebei urban is a typical water-deficient area. As an important part of the urban-rural integration construction, evaluating the health status of the Beiyun River Basin and discovering the weak links in the water environment are the basis for improving the health of the basin.

Evaluating surface water quality using water quality index in Beiyun River, China.

The Beijing-Tianjin-Hebei urban agglomeration is one of the most water-scarce regions in China, because of the frequent human activities. Water scarcity and pollution have weakened the service functions of water ecosystems and hindered the regional economic development. As the "lifeline" of the economic development of Beijing-Tianjin-Hebei region, the water quality of Beiyun River has been widely concerned.

Aqueous synthesis of Cu-doped ZnCdS/ZnS core/shell nanocrystals with a new and highly reactive sulfur source.

A new sulfur precursor with a highly reactive chemical nature was prepared with S powder and NaBH₄ at the high temperature of 180 °C in a closed autoclave and made it possible to carry out the synthesis of high quality metal sulfide nanocrystals (NCs) with diverse composition and structure. Using this new sulfur source, we demonstrated aqueous synthesis of colloidal Cu-doped ZnCdS NCs (d-dots) with pure, color-tunable photoluminescence (PL) in a wide spectral range (from 517 to 650 nm) based on the 'co-nucleation doping' strategy. The influences of the various experimental variables, including Cd/Zn ratio, Cu-doping concentration, pH value and amount of mercaptopropionic acid (MPA), on the optical properties of Cu-doped ZnCdS NCs were systematically investigated.

Facile synthesis of Mn-doped ZnS nanocrystals and determination of critical temperature for lattice diffusion process.

High-quality Mn:ZnS doped nanocrystals (d-dots) with photoluminescence (PL) quantum yield (QY) of 50-70% have been synthesized based on nucleation-doping strategy by choosing 1-dodecanethiol (DDT) as the capping ligand. Controlling the growth of small-sized MnS core nanoclusters was successfully achieved by changing the injection temperature of sulfur precursor, the growth time of MnS nuclei, and the amount of DDT. Furthermore, MnS/ZnS core/shell d-dots with a diffusion layer at the interface between the MnS core and the ZnS shell were fabricated through an overcoating of the ZnS shell layer on the presynthesized MnS core nanoclusters.

Speciation analysis and characterisation of arsenic in lavers collected from coastal waters of Fujian, south-eastern China.

Laver samples (Porphyra haitanensis) were collected from the coastal waters of Fujian province, south-eastern China and then the speciation characteristics of arsenic in the samples were studied in detail. These laver samples contained five arsenical species, namely arsenobetaine, monomethylarsonic acid, As(V) and two kinds of arsenic-containing ribosides (arsenosugars), with a relatively high concentration of total arsenic in the range of 28.85-63.

Speciation analysis of mercury in natural water and fish samples by using capillary electrophoresis-inductively coupled plasma mass spectrometry.

A environment-friendly microwave-assisted extraction used to extract trace mercury compounds from fish samples, and a ultra-sensitive method for the analysis of Hg(II), methylmercury (MeHg) and ethylmercury (EtHg) by using capillary electrophoresis-inductively coupled plasma mass spectrometry (CE-ICP-MS) were described in this study. The extraction method is environment-friendly, simple, effective, and can be used to extract trace mercury compounds in fish samples with a satisfied recovery within several minutes. The CE-ICP-MS analytical method has a detection limit as lower as 0.

[Speciation analysis of arsenic in seaweeds by capillary electrophoresis-inductively coupled plasma mass spectrometry].

A method for the detection of trace As (III), As (V), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenocholine (AsC) and arsenobetaine (AsB) in seaweeds by capillary electrophoresis-inductively coupled plasma mass spectrometry (CE-ICP-MS) was developed. The optimized conditions of CE including chemical component, pH and concentration of the buffer, separation voltage and injection time were studied in detail. The results showed that the above six species of arsenic were baseline separated within 25 min under the optimized conditions.

Speciation analysis of selenium in rice samples by using capillary electrophoresis-inductively coupled plasma mass spectrometry.

An enzyme-assisted extraction used to extract all species of selenium in rice sample and a sensitive analytical method for the determination of ultratrace Se(VI), Se(IV), SeCys(2) (selenocystine) and SeMet (selenomethionine) with capillary electrophoresis-inductively coupled plasma mass spectrometry were firstly described in this study. The extraction method is simple, effective and can be used to extract trace selenium compounds in rice with high extraction efficiency and no altering its species. The analytical method has a detection limit of 0.