Detection of Endocrine Disruptors in Water around Landfills

[Objectives]This study was conducted to explore the occurrence levels of endocrine disruptors(EDCs)in rural areas around a county landfill in Tongren City.[Methods]The water around the landfill was sampled and analyzed.A solid-phase extraction and high performance liquid chromatography-tandem mass spectrometry(SPE-UPLC-MS/MS)method was established for the determination of 27 EDCs.After the HLB solid-phase extraction column was activated,a water sample,which was adjusted with phosphoric acid to a pH of 2(±0.5)and added with 500 mg of disodium EDTA,was loaded,and 5 ml of water and 20%methanol water was added for washing.Next,10 ml of elution solution was added for elution,and the collected eluate was evaporated under reduced pressure at 40℃to near dryness,and 1 ml of reconstitution solution was added to a constant volume.An ACQUITY UPLC BEH C18(100×2.1 mm,2.6μm)chromatographic column was adopted for LC separation by gradient elution with pure water solution-acetonitrile as the mobile phase.For MS detection,the MRM mode was adopted for collection,and the positive and negative ion modes were switched for simultaneous determination,and the internal standard method was used for quantification.[Results]The correlation coefficient R2 was greater than 0.99 in the linear range of each target substance.The limits of quantitation in the method were between 0.05 and 2.00 ng/L,and the recoveries ranged from 75.3%to 105.7%.[Conclusions]The method has high sensitivity,good accuracy and strong practical value.

Determination of Coumoxystrobin Residues in Milk

[Objectives]This study was conducted to establish a liquid chromatography-tandem mass spectrometry method for the determination of coumoxystrobin residue in milk.[Methods]A sample was ultrasonically extracted with acetonitrile,purified by a solid phase extraction column,concentrated by nitrogen blowing,and tested on a machine.[Results]In the range of 0.01-10.00 mg/kg,the linear relationship of coumoxystrobin was good.The linear equation was y=5045.96x+935.332,r^(2)=0.999.The detection limit was 0.002 mg/kg,and the quantitation limit was 0.006 mg/kg.The method has good stability,high precision,and the detection limit can meet the limit requirement of coumoxystrobin in GB 2763-2019.[Conclusions]This study can provide technical support for the supervision and monitoring of coumoxystrobin.

Strategic Communications of the Muslim Brotherhood in Egypt

As the oldest and largest religious political organization and a political opposition,the Muslim Brotherhood has long been active in the Egyptian political arena.The eruption of the‘January 25th Revolution’in 2011 enabled the Muslim Brotherhood to successfully move from behind the scenes to the stage,and the Freedom and Justice Party under the Muslim Brotherhood was highlighted in Egyptian politics and succeed in the administration of the Egyptian regime.The successful development model of the Muslim Brotherhood is closely related to its strategic communication tactics.This article explores the various strategic communication tactics of the Muslim Brotherhood targeting the internal public,the international community and the stakeholders,including vertical word-of-mouth strategic communications,joint organization strategic communications and social media strategic communications.After the‘January 25th Revolution’,the Muslim Brotherhood began to adjust to the previous strategic communications,focusing on accelerating the Islamization of the Egyptian legal system,government departments and official media,and new strategic communications have trapped it into a difficult position and it has been faced with more hurdles.