Determination of egg and milk allergen in food products by liquid chromatography-tandem mass spectrometry based on signature peptides and isotope-labeled internal standard

The aim of this work was to develop a liquid chromatography-tandem mass spectrometry method for the determination of milk allergen and egg allergen in food products.Signature peptides GGLEPINFQTAADQAR,VGINYWLAHK,VLVLDTDYK,FFVAPFPEVFGK,and NAVPITPTLNR were confirmed and synthesized as the quantitative peptide of ovalbumin,α-lactalbumin,β-lactoglobulin,α_(S1)-casein andα_(S2)-casein,the relative isotope-labeled internal standards were used in the quantitative analysis.Linear range was in the range of0.5-5000.0 nmol/L for egg and milk allergen in bread,cake,cookie,rice crust and wheat flour samples with free from egg and milk,the limits of detection of milk allergens and egg allergen were in the range between0.94 mg/100 g and 56.71 mg/100 g,limits of quantification of milk allergens and egg allergen were in the range between 2.36 mg/100 g and 141.78 mg/100 g.The recoveries ranged from 76.7%to 122.8%,the relative standard deviations were in the range of 1.60%-15.60%.The developed method has been successfully used for the detection of egg and milk allergen in various food samples.

Unraveling the decomposition mechanism of Li_(2)CO_(3)in the aprotic medium by isotope-labeled differential electrochemical mass spectrometry

Rechargeable lithium-ion batteries(LIBs)represent the highest energy density in the contemporary energy storage community,typically delivering a practical energy density of 150-350 Wh kg-1in the current technique,which can hardly satisfy the evergrowing demand for the portable electronic devices and power tools requiring long service time[1-3].

LiOH: A "double-edged" effect toward electrochemical oxidation of Li_(2)O_(2)

The aprotic lithium-oxygen battery(Li-O_(2) battery) has attracted much attraction for the future advanced battery technologies due to its ultra-high theoretical energy density that can well meet the ever-growing energy demand of portable electronic products,electric vehicles(EVs),smart grids,and so on [1-5].In principle.

Cadmium found in peanut (Arachis hypogaea L.) kernels mainly originates from root uptake rather than shell absorption from soil

Roots and shells are two potential organs through which peanut plants absorb cadium(Cd)from soils;however,the relative contributions of the two uptake pathways(root uptake and shell absorption)to kernel Cd accumulation and their translocation characteristics are poorly understood.In this study,the relative contributions of the two pathways to Cd accumulation in two peanut cultivars,Xianghua2008(XH)and Yueyou43(YY),were accurately assessed by labeling rooting and podding zone soils with 113Cd and 111Cd isotopes(0.3 mg kg^(-1) dry soil),respectively,in a split-pot design.The results showed that approximately 96%of the Cd accumulated in the peanut kernels was derived from root uptake,while only 4%originated from shell absorption.Only 1%of the Cd accumulated in whole peanut plants was attributed to shell absorption,of which 41%–44%was retained in shells and 56%–59%was translocated to kernels.In contrast,the Cd absorbed by roots was efficiently translocated into all plant organs,of which 80%–84%was distributed in shoots.Although YY accumulated 1.3 times more Cd in whole plants than XH,the relative contributions of the two pathways to Cd accumulation in each plant organ were barely affected by peanut cultivars.Due to the strong retention effect of shells,shell-derived Cd was approximately 2 times higher than root-derived Cd in shells.These results would improve the understanding of Cd accumulation processes in peanut plants,revealing that the root uptake pathway contributes predominantly to the Cd concentration in peanut kernels,based on which strategies and technology for the reduction of Cd in peanut plants could be designed and developed.

Anaerobic oxidation of methane coupled to sulfate reduction: Consortium characteristics and application in co-removal of H_2S and methane

Anaerobic sludge from a sewage treatment plant was used to acclimatize microbial colonies capable of anaerobic oxidation of methane(AOM) coupled to sulfate reduction. Clone libraries and fluorescence in situ hybridization were used to investigate the microbial population.Sulfate-reducing bacteria(SRB)(e.g., Desulfotomaculum arcticum and Desulfobulbus propionicus)and anaerobic methanotrophic archaea(ANME)(e.g., Methanosaeta sp. and Methanolinea sp.)coexisted in the enrichment. The archaeal and bacterial cells were randomly or evenly distributed throughout the consortia. Accompanied by sulfate reduction, methane was oxidized anaerobically by the consortia of methane-oxidizing archaea and SRB. Moreover, CH_4 and SO_4^(2-) were consumed by methanotrophs and sulfate reducers with CO_2 and H_2S as products. The H_3CSH produced by methanotrophy was an intermediate product during the process. The methanotrophic enrichment was inoculated in a down-flow biofilter for the treatment of methane and H_2S from a landfill site. On average, 93.33% of H_2S and 10.71% of methane was successfully reduced in the biofilter. This study tries to provide effective method for the synergistic treatment of waste gas containing sulfur compounds and CH_4.

Advance of swainsonine biosynthesis

Swainsonine （1） belongs to the family of indolizine alkaloid with strong neurologically toxic effects on herbivorous livestock. Recently, a great amount of evidence confirmed that this alkaloid displayed a wide range of bioactivities especially anti-cancer biological effects. The potential targets of swainsonine （1） were now revealed to be the mannosidase and Golgi mannosidase 1I. Its low yield in plants or fungi, and no economically total synthesis route in practice as the key bottleneck restricted its further structure- activities relationships （SAR） investigation in drug discovery. This mini-review highlighted the biosynthetic advance of swainsonine （1） from 1973 to 2017 based on the results of isotope-labelled experiments and the recent research of its biosynthetic gene cluster, which could provide some thoughts for further biosynthetic investigation and efficiently biomimetic synthesis of swainsonine （1） in order to increase its output in practice.