液相微萃取-气质联用法在增塑剂测定中的应用和对比

对比并优化3种液相微萃取模式:静态直接浸入法、动态直接浸入法和中空纤维膜法,并与气相色谱-质谱联用检测饮品中邻苯二甲酸酯类。静态直接浸入法以2.0μL甲苯-环己烷(3∶1,V/V)混合溶剂微滴在500 r/min转速下静态萃取40 min,动态直接浸入法以2.0μL甲苯微滴在400 r/min转速下,以1次/min的活塞抽打速率抽打25次,中空纤维膜法以20μL辛醇在800 r/min转速下萃取30 min。3种方法检测水体中邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二正丁酯以及邻苯二甲酸丁基卞基酯的线性范围、相对标准偏差分别为0.50~500μg/L(3.01%~13.7%),0.10~10μg/L(17.3%~23.1%)及0.10~100μg/L(8.10%~15.5%)。应用于实际饮品中邻苯二甲酸酯类的测定,3种方法的回收率分别为89.5%~115.2%,70.6%~91.0%和91.5%~112.8%。     

Thermal apoptosis analysis considering injection behavior optimization and mass diffusion during magnetic hyperthermia

Thermally induced apoptosis for tumors depends mainly on the intrinsic characteristics of biological tissues as well as treatment temperature profile during magnetic hyperthermia.Further,treatment temperature distribution inside tumor depends on the injection behavior of irregular tumors,such as the injection dose and the injection location of nanofluids.In order to improve the treatment effect,the simulated annealing algorithm is adopted in this work to optimize the nanofluid injection behavior,and the improved Arrhenius model is used to evaluate the malignant ablations for three typical malignant tumor cell models.In addition,both the injection behavior optimization and the mass diffusion of nanofluid are both taken into consideration in order to improve the treatment effect.The simulation results demonstrate that the injection behavior can be optimized effectively by the proposed optimization method before therapy,the result of which can also conduce to improving the thermal apoptosis possibility for proposed typical malignant cells.Furthermore,an effective approach is also employed by considering longer diffusion duration and correct power dissipation at the same time.The results show that a better result can then be obtained than those in other cases when the power dissipation of MNPs is set to be QMNP=5.4×10⁷W·m³ and the diffusion time is 16 h.     

药物中间体(S)-3-羟基四氢呋喃的合成研究

(S)-3-hydroxy-tetrahydrofuran was synthesized from L-malic acid by esterification,reduction,cyclization.The chemical structures of the target compound was identified by element analysis,IR,NMR andMS spectra.The total yield and the purity of the product were 41% and 99.2%,the optical purity was 95.8%.This optimal synthetic procedure with lower cost and mild reaction conditions be worthy to have a further pilot manufacture.