超高效液相色谱法测定食品包装材料中的富马酸二甲酯

提出了内标法结合超高效液相色谱法测定食品包装材料中富马酸二甲酯的方法。以包装企业自送的4种包装材料为例,讨论了用超高效液相色谱进行富马酸二甲酯测定的过程。该方法的检出限为10μg/kg,加标回收率在76%～98%之间,相对标准偏差在1.2%～4.1%之间。实验结果表明,用溶剂萃取结合超高效液相色谱能够满足日常进出口食品包装材料中富马酸二甲酯的检测。     

反相高效液相色谱法测定可乐中咖啡因的含量

建立用反相高效液相色谱法(RPLC)测定可乐中咖啡因的方法。可乐试样先用超声清洗器在40℃下超声5min,然后经前处理柱过滤,除去绝大部分有机物,最后经过0.45μm水系滤膜过滤后方可进样,通过Diomonsil C18(2)5 u色谱柱分离,以甲醇+水混合溶液为流动相进行洗脱,于286 nm波长下紫外检测。咖啡因在10～150μg/mL范围内的线性关系良好,在加标水平为60,80,100μg/mL时,被测物的回收率为96.8%～101.8%。     

二氯喹啉酸的高效液相色谱法测定

建立了二氯喹啉酸的高效液相色谱(HPLC)快速检测方法。二氯喹啉酸俗称快杀稗,属激素型喹啉羧酸类除草剂。用高效液相色谱法测定除草剂中二氯喹啉酸的含量,通过改变高效液相色谱的检测波长、流动相的配比,确定测定二氯喹啉酸的最佳测定条件,以甲醇+水+冰乙酸(85:15:0.1)为流动相,采用C18柱(250 mm×4.6 mm×5μm)分离,在uV238 nm检测,外标法定量。以SPD-10AVP型检测器对试样中的二氯喹啉酸原药进行分离和定量分析。结果表明,二氯喹啉酸的线性相关系数为R=0.9998;标准偏差为0.29;变异系数为0.36;回收率82%～94%。     

高效液相色谱法和超高效液相色谱-三重四级杆串联质谱法测定水中阿特拉津的方法比较

本文对测定水中阿特拉津的两种方法(高效液相色谱法和超高效液相色谱-三重四级杆串联质谱法)进行了比较。结果表明,在一定浓度范围内,两种方法的标准工作曲线线性均良好;两种方法的检出限均符合《地表水环境质量标准》的要求;精密度也均符合实验方法要求;方法也均具有较强的抗干扰能力;两种方法加标回收率分别为85.1%-98.5%和95.0%-105%,相对标准偏差分别为1.8%-3.7%和2.0%-3.6%。     

高效液相色谱法测定妥布霉素的含量

本文采用高效液相色谱法测定妥布霉素的含量,以Waters Nova-pak C_(18)为固定相,水—冰醋酸—甲醇—乙腈(40:5:30:25 v/v)配制的庚烷碘酸钠溶液(0.02mol/L)为流动相,在330nm处测定,线性范围0.1～0.6mg/ml,r=0.9988。方法简便、快速,重现性良好。     

高效液相色谱法测定饲料中角黄素

建立了测定饲料中角黄素的高效液相色谱(HPLC-DAD)分析方法。样品经皂化法处理,用石油醚提取,经浓缩处理后,用甲醇和三氯甲烷的混合溶液(10+1)溶解,用XB-C_(18)柱(150 mm×4.6 mm,5μm)分离,以乙腈为流动相进行等度洗脱。目标分析物在相应的质量浓度范围内线性关系良好,线性相关系数(R~2)为0.9996,检出限为0.13 mg/kg,回收率为88.5%~93.9%,相对标准偏差为1.6%~2.9%。本方法准确、简便、快速,方法精密度、准确度和回收率能满足饲料中角黄素样品检测的要求。     

高效液相色谱法（HPLC）测定饲料中三聚氰胺的含量

本文建立了饲料中三聚氰胺的HPLC测定方法。该法采用Symmetry C18柱为分离柱,二极管阵列紫外检测器进行样品检测（λmax=236nm）。方法简单、快速、重现性好,平均回收率大于90％,RSD小于3．0％,线性范围为1mg／L-100mg／L。     

高效液相色谱法测定食品中姜黄素

本文研究建立了食品中姜黄素的高效液相色谱测定方法。样品中的姜黄索经乙醇：氨水（3：1）提取后,聚酰胺吸附,再经甲醇氨水洗脱、浓缩,液相色谱二级管阵列检测器检测。姜黄索标准在0．5μg／mL-50μg／mL范围内具有良好的线性,该方法回收率高,样品定量检测限（LOQ）为0．2mg／kg,可作为糖果、糕点、面制品等食品的定量检测方法。     

高效液相色谱法测定鸢尾根茎中鸢尾酮的含量

建立高效液相色谱外标法测定鸢尾根茎中的鸢尾酮含量。采用C18色谱柱,流动相比例为乙腈：水=7:3,流速为1mL/min,柱温35℃,检测波长230nm。trans-α-鸢尾酮在0.0930-1.8609μg线性良好,cis-α-鸢尾酮在0.0888-1.7751μg线性良好,陈化香根鸢尾根茎中cis-α-鸢尾酮平均加样回收率为97.47%(n=9),两批陈化香根鸢尾根茎中cis-α-鸢尾酮含量分别为130.9μg/g,122.6μg/g（以干燥陈化香根鸢尾根茎计,下同）。同时,应用本方法对不同来源的鸢尾标本进行检测,测得采集于阿勒泰地区的膜苞鸢尾标本根茎中cis-α-鸢尾酮含量最高,可达177.5μg/g。故本方法可用于鸢尾根茎中鸢尾酮含量的检测;膜苞鸢尾或可作为天然来源的鸢尾酮的源植物。     

高效液相色谱法快速测定小麦粉中过氧化苯甲酰

目的:用高效液相色谱准确、快速测定小麦粉中过氧化苯甲酰。方法:小麦粉直接以水溶解,经振荡及超声提取,滤膜过滤后上高效液相色谱进行测定。结果:苯甲酸在0.2μg/ml～100μg/ml范围内呈良好线性,检出限为0.3mg/kg。平均回收率在94.1%～99.0%范围内。相对标准偏差小于2%。经检验,本法对CNCA能力验证剩余样品的检测结果与CNCA公布结果基本一致。结论:本法简单快捷,结果准确,重现性好,适用于小麦粉中过氧化苯甲酰的测定。     

食品包装用PVC瓶盖垫片中增塑剂DEHP的迁移研究

为了解PVC垫片接触各类食品的安全性,采用气相色谱-质谱联用法研究了PVC垫片中DEHP在乙醇和正己烷中的迁移行为及其影响因素。实验结果表明:随着时间的延长,DEHP的迁出量逐渐增加;PVC垫片厚度越小,DEHP越容易迁出;与乙醇相比,DEHP更容易向正己烷中迁移,PVC垫片应避免接触脂肪类食品。     

布基管和布基洋葱的富集和结构

利用扫描电镜和高分辨投射电镜对布基管和布基洋葱的制备、形貌做了研究，发现了大量含有布基管的高密区及表面特征，观测到的布基管可达４微米。报导了几种布基管的形貌，对其生长机理做了探讨。     

UPLC法测定麻辣火锅底料中的辣椒素

通过实验比较高效液相色谱法(HPLC)和超高压液相色谱法(UPLC)对麻辣火锅底料中辣椒素含量的测定,发现UPLC分析方法较优,辣椒素在UPLC色谱条件下的分离时间仅为HPLC分离时间的1/4.实验结果表明,UPLC测得的辣椒碱和二氢辣椒碱在一定范围内线性良好,回收率为91.28%～102.36%,精密度为1.11%～3.41%.对15种麻辣火锅底料辣椒素含量的测定结果表明,麻辣火锅底料中辣椒碱含量平均约为79.0 mg/kg,二氢辣椒碱含量平均约为34.01mg/kg.     

UPLC同时测定保健药物中的7种茶多酚和咖啡因

采用超高压液相色谱法在15 min内实现了茶类保健药物中7种茶多酚和咖啡因的基线分离,并确定了8种目标化合物的最小检测限和线性等技术参数,最小检测限在0.06～0.11μg/mL之间,线性相关系数为.9999.实验同时研究了提取温度、有机相比例等提取条件对于测定结果的影响.最后,采用新建立的方法对3种市售保健茶药物中的8种化合物进行了计量学检测,结果显示本方法适合用于茶多酚类化合物的准确分析和定量.     

Experimental Investigation of Strain Concentrations Caused by Inserts in Sandwich Beams

Abstract:  This paper presents an experimental study of the strain concentrations developing across the insert–core junctions in a sandwich beam with an implanted stiff insert into its core. Strain measurements were carried out at several positions on the skins and across the insert–core junction, for several sandwich beam specimens loaded in 3-points bending and having inserts with various geometries. The materials used were typical marine glass/polyester composite and PVC foams and the specimens were manufactured with the vacuum infusion method. A full material characterization was performed for the composite skins. The experimental results demonstrated a pure linear bending response of the specimens, as well as significant strain concentration factors across the insert–core junction, reaching values up to 3.3. Strain concentration factors measured for butt inserts were lower than those measured on the tension side of the specimens with scarf inserts. Transverse strains measurements verified that all specimens were in a plane stress state.     

超高效液相色谱-串联质谱法对鳗鱼及制品中禾草丹残留量的测定

本文建立了用超高效液相色谱-串联质谱法对鳗鱼及制品中禾草丹的检测方法。采用乙腈对样品中的禾草丹进行提取,浓缩后用固相萃取SPE小柱、氧化铝、无水硫酸钠进行净化,最后用超高效液相色谱-质谱联用法进行分离和定性定量分析。方法线性相关系数为0.9966,5-20μg/kg,加标样品的回收率在75%-85%之间,相对标准偏差在8.3%-12.7%,定量检出限可达到0.5μg/kg,该方法具有快速、高效、灵敏度高,符合出口检测限量的要求。     

Inhibitory effect of resveratrol on the pharmacokinetic of ibrutinib by UPLC–MS/MS

Objective: To investigate the impact of resveratrol on the metabolism of ibrutinib in vitro and in vivo.

Methods: In vitro, rat liver microsomes (RLM) and human liver microsomes (HLM) were used to study. In vivo, 18 male SD rats were randomly divided into three groups (n?=?6): ibrutinib and the multiple dose of 100?mg/kg resveratrol for consecutive 7 days (Group A), ibrutinib and the single dose of 100?mg/kg resveratrol (Group B), ibrutinib (Group C). Processed samples were analyzed by UPLC–MS/MS.

Results: Resveratrol showed inhibition on RLM and HLM in vitro. The IC₅₀ of resveratrol was 8.745?µM in RLM and 7.789?µM in HLM. Furthermore, Groups A and B both increased the AUC and reduced the CLz/F. The C_max of Group A and the MRT_(0–t) of Group B were significantly improved.

Conclusions: Resveratrol inhibits the pharmacokinetic of ibrutinib in vitro and in vivo. It is necessary to pay more attention to adjust the dose of the drug when resveratrol is used in combination with ibrutinib.     

Stress Concentrations Caused by Embedded Optical Fiber Sensors in Composite Laminates

The fiber optic sensor (FOS) embedded perpendicular to reinforcing fibers causes an `Eye' shaped defect. The length is about 16 times fiber optic radius (R_Fos) and height is about 2R_Fos. The eye contains fiber optics in the center surrounded by an elongated resin pocket. Embedding FOS causes geometric distortion of the reinforcing fiber over a height equal to 6 to 8 R_Fos. This defect causes severe stress concentration at the root of the resin pocket, the interface (in the composite) between the optical fiber and the composite, and at 90° to load direction in the composite. The stress concentration was calculated by finite element modeling of a representative micrograph. The FE results agreed reasonably with analytical and experimental data in the literature for a similar problem. The stress concentration in axial direction was about 1.44 and in transverse direction at the interface was -0.165 and at resin pocket was 0.171. Under tensile loading, the initial failure was by transverse matrix cracking (fiber splitting) at the root of the resin pocket, then that lead to final fracture by fiber breakage. Under compression loading, the failure initiation was by interfacial cracking due to large transverse tensile stress and the final fracture was by compression. Fracture stress calculated from the analysis using the maximum stress criteria agreed reasonably with test data.     

超高效液相色谱-串联质谱技术检测番茄制品中矮壮素及缩节胺残留量的方法研究

本文采用超高效液相色谱-串联质谱(UPLC-MS/MS)技术,同时检测番茄制品中矮壮素及缩节胺残留的方法。结果表明,番茄制品经稀释定容、超声浸提、高速离心后,采用UPLC-ES(I+)MS/MS同时测定番茄制品中矮壮素及缩节胺的残留,在0.001～0.05mg/kg浓度范围内,平均加标回收率在80%-110%,方法检出限0.01mg/kg,可同时满足出口番茄酱制品中矮壮素及缩节胺检测工作的需要。     

C/C复合材料在原子氧辐照下的结构性能演变

通过分析失重率、显微形貌变化讨论了原子氧辐照对C/C复合材料以及SiC基体改性C/C复合材料(C/C-SiC)的损伤机制; 并通过热膨胀系数(CTE)、热扩散率(TD)以及弯曲强度等性能的变化, 进一步讨论了原子氧辐照损伤对材料热物理及力学性能影响。结果表明, C/C复合材料受原子氧辐照损伤是物理化学综合作用, 属于冲击诱发-增强表面化学刻蚀; SiC组元表现出良好的抗原子氧侵蚀性能, 阻碍了原子氧向材料内部侵蚀, 但是SiC组元在更长时间辐照后出现机械破损; C/C复合材料在原子氧辐照下失重率呈线性增加, 而C/C-SiC复合材料失重率小于C/C复合材料且增长幅度越来越小; C/C复合材料和C/C-SiC复合材料的整体结构性能在辐照损伤后发生了一定变化。