Ultra trace level determinations of acrylamide in surface and drinking water by GC–MS after derivatization with xanthydrol

A sensitive GC–MS method has been established for the determination of acrylamide in surface and drinking water based on derivatization with xanthydrol. Deuterated acrylamide (acrylamide‐d₃) was chosen as the internal standard for analyzing the water sample. The derivatization of acrylamide was performed directly in water, and the best reaction conditions (xanthydrol of 1.6 mM, HCl concentration of 0.05 M, reaction for 30 min at ambient temperature) were established by variation of parameters. Under the established conditions, the detection and quantification limits were 3.0 and 9.7 ng/L, respectively, and the interday RSD was less than 8% at concentrations of 20 and 100 ng/L.     

Theoretical Design and Adsorption Properties of Molecularly Imprinted Polymers Obtained from Chloramphenicol and Acrylamide

Molecular simulations are widely used to model molecularly imprinted polymers(MIPs) in order to enhance their adsorption and selectivity. In this study, chloramphenicol(CAP) and acrylamide(AM) were used as the template and functional monomer, respectively, and pentaerythritol triacrylate(PETA), ethylene glycol dimethacrylate (EGDMA), and trimethylolpropane trimethylacrylate(TRIM) were used as cross-linking agents. The ωB97XD/6-31G(d,p) density functional theory method was employed to simulate binding sites, binding energy, the number of hydrogen bonds, the imprinted molar ratio, which produced the most stable complex, and the interaction mechanism. The cross-linking agent was optimized based on the binding energy. The atoms in molecules theory were used to study the nature of the imprinting effects. The theoretical calculations revealed that CAP and AM formed ordered complexes via hydrogen bonding interactions when the molar ratio between CAP and AM was 1:7 using TRIM as the cross-linking agent. The CAP-AM complex(molar ratio 1:7) had the most stable structure, the largest number of hydrogen bonds, and the smallest ∆E. The experimental results indicate that the CAP-MIPs formed perfect microspheres with an average particle size of 314 nm. Scatchard plot analysis showed that the CAP-MIPs had only one type of binding site over the studied concentration ranges. The dissociation equilibrium constant and maximum apparent adsorption capacities were 1887.35 mg/L(5.84 mmol/L) and 155.56 mg/g(0.482 mmol/g), respectively.     

Studies on Interaction of Hydrophobically Modified Polyacrylamide of a New Family with Cationic Gemini Surfactant

A new family of hydrophobically modified polyacrylamides (HMPAM) was synthesized via homogeneous copolymerization of acrylamide (AM) and anionic surface-active monomer of acrylamide-type, sodium 2-acrylamido-tetradecane sulfonate (NaAMC₁₄S) in aqueous solution. The copolymers NaAMC₁₄S/AM with microblock structures and with different chain microstructures were obtained by varying the copolymerization factors, such as the feed ratio of NaAMC₁₄S to AM and the amount of added electrolyte NaCl and initiator. The interaction between copolymers NaAMC₁₄S/AM and cationic gemini surfactants, C₁₂C₃C₁₂Br₂ and C₁₂C₆C₁₂Br₂, was studied by using viscosimetry and fluorescent probe technique. The results show this new family of HMPAM, NaAMC₁₄S/AM, has very strong interaction with gemini surfactants, and their aqueous solutions exhibit unique rheological properties.     

Studies on rheological behaviour of hydrophobically associating polyacrylamide with strong positive salinity sensitivity

Hydrophobically associating polymer has been obtained by homogeneous copolymerization of acrylamide and an anionic surface-active monomers (surfmer) of acrylamide-type, sodium 2-acrylamido-tetradecane sulfonate (NaAMC₁₄S) in aqueous solution, and under different concentration conditions of NaAMC₁₄S above its critical micellar concentration (CMC) and below CMC, two structure types of copolymers P (AM–NaAMC₁₄S) were prepared in which main chains NaAMC₁₄S were distributed in microblock and in random manner, respectively. The hydrophobically associating property and rheological behaviour of the copolymers were studied with viscosimetry and then by fluorescence probe method. It was found that the apparent viscosity of the aqueous solution of the copolymers with microblock structures exhibits strong positive salinity sensitivity, whereas the positive salinity sensitivity of the apparent viscosity of the aqueous solution of the copolymers with random structure only appears generally and the apparent viscosity was diminutively increased because of salinity-promoting hydrophobic association. For those copolymers with microblock structures, the apparent viscosities of their brine solution are much higher than that of their pure water solution. In CaCl₂ solution (2 wt%), as the copolymer concentration attains 0.2 wt%, the apparent viscosity enhances dramatically with the increase in concentrations, and as the copolymer concentration was 0.3 wt%, the apparent viscosity can enhance by almost two orders of magnitude (from 32 to 1,000 mPa·s) as compared with in pure water solution. Thus, for copolymer P (AM–NaAMC₁₄S) with microblock structure, the peculiar positive salinity sensitivity, i.e. salinity thickening, is displayed distinctly. The unusual positive salinity sensitivity of copolymers P (AM–NaAMC₁₄S) with microblock structure was also revealed by fluorescence probe method, and the value I ₁/I ₃ of pyrene in the brine solution of the copolymers was smaller than that in pure water solution of the copolymers. This unique salinity sensitivity is a reflection of the unusual microstructure of the copolymers. The experiment results are interpreted in terms of the effects of the surfmer distribution manner in the copolymer main chain and bonding way of the ionic surfmer to the copolymer main chain on the forming intermolecular association.     

HPLC测定人体组织中的奥美定中丙烯酰胺的含量

高效液相色谱法测定人体组织中的奥美定中丙烯酰胺的含量。采用色谱柱Diamonsil C18（5μm,4.6mm×250mm）;甲醇-水（90∶10）为流动相;流速为0.6mL/min;检测波长210nm;柱温为室温。丙烯酰胺在20—30μg/mL浓度范围内,峰面积与浓度呈良好的线性关系,回归方程为y=19204x-87188,r=0.9997,平均回收率为96.7%。该方法样品处理简单,准确度高,精密度好,适合人体组织中丙烯酰胺含量的测定。     

一种利用梯度光掩模制备梯度表面的简便方法

以自制杂化双向拉伸聚丙烯/氧化硅(BOPP/SiOx)有机/无机杂化膜为基材,由喷墨打印机直接在杂化膜表面打印色阶图案,制备出对紫外光强度呈梯度透过的梯度光掩模;通过此掩模控制,在双向拉伸聚丙烯(BOPP)和聚对苯二甲酸乙二醇酯(PET)表面实施受限光催化氧化(CPO)光感应羟基化反应、受限光接枝丙烯酸(AA)以及表面...     

N‐Triazolylpropanamide – an Acrylamide‐Derived Multifunctional Ligand for the Construction of Supramolecular Hydrogen‐Bonded Networks

The synthesis and single crystal X‐ray structure of the multifunctional acrylamide‐derived ligand N‐triazolylpropanamide ( 1 , = NTPA) are reported. The title compound was prepared in 72 % yield by Michael addition of 1, 2, 4‐triazole and acrylamide in the presence of Triton B (= trimethylbenzylammonium hydroxide) as catalyst. Treatment of 1 with FeCl₃(H₂O)₆ in MeOH/MeCN led to reduction and formation of the iron(II) complex (NTPA)₂FeCl₂(MeOH)₂ ( 2 , yellow prisms, 52 % yield). Both 1 and 2 were structurally characterized by X‐ray diffraction. Surprisingly, the NTPA ligands in 2 are coordinated to iron in a monodentate fashion through a triazole ring nitrogen atom. In the crystal, both compounds form supramolecular hydrogen‐bonded networks.     

Preparation and Antibacterial Activity of Copolymer of Methacryloxyethyldimethyl Dodecyl Ammonium Bromide/Acrylamide

Copolymers PMDAB-co-AA with excellent antibacterial activity were designed and prepared (MDAB/AA=methacryloxyethyldimethyl dodecyl ammonium bromide with acrylamide). The chemical structures of the copolymers were characterized by Fourier transform infrared(FTIR), ¹H NMR, ¹³C NMR and chemical titration. The antimicrobial activities and kinetics of the copolymer against E. coli and S. aureus were examined by viable cell counting method. The compositions of the copolymers could be easily controlled by the feed molar ratio of MDAB to AA. Furthermore, the highest antibacterial activity was achieved when the molar fraction of MDAB was in a range of 5%-20%, and the killing rate reached 100% under the test conditions. In addition, the antibacterial activity of PMDAB-co-AA was maintained and stable without any loss after 15 times of repeated usage. It was proved that the PMDAB-co-AA samples targeted at cell membrane, and caused serious damage to cell integrity and inner membrane permeation. The surrounding conditions, such as pH and inorgainc salts concentrations(CaCl₂ or NaCl), also affected their antibacterial activities.     

姜黄素在丙烯酰胺聚合物中的发光特性研究

以丙烯酰胺为功能单体、乙二醇二甲基丙烯酸酯为交联剂 ,在聚合之前的溶液体系中均匀混入荧光分子姜黄素 ,制备了具有光致发光性能的块状聚合物 ,并将此聚合物粉碎为 4 0～ 75 μm直径的粉末。姜黄素在此聚合物中与其在乙醇溶液中相比 ,其荧光发射光谱有明显的蓝移现象。用同样方法制备的含有罗丹明 6G、四碘荧光素、荧光桃红的丙烯酰胺聚合物也有类似的现象 ,初步认为此蓝移现象的机理可能是聚合物的三维空间网状结构对于荧光分子的隔离效应导致其接近于单分子发光所致