Tạp chí Phân tích Hóa, Lý và Sinh học

   A method for the simultaneous determination of paralytic shellfish poisoning toxins incrab by liquid chromatography tandem mass spectrometry (LC-MS/MS) wasdeveloped and validated. The proposed method has good specificity, high sensitivity,acceptable repeatability and recovery. The method limit of detection and limit ofquantitative for each toxin is 100 μg/kg and 300 μg/kg, respectively. The method hasbeen applied for the PSP toxins determination in 30 crab samples.

      Complexes of benzaldehyde thiosemicarbazone (HL1), benzaldehyde N(4)- phenyl thiosemicarbazone (HL2), isatin thiosemicarbazone (HL3) and isatin N(4)- methyl thiosemicarbazone (HL4) with copper(II) were synthesized in base medium of NH3. Form of these complexes were Cu(L)2, which L: L1, L2, L3, L4. The chemical structures of ligands and their complexes were characterized by elemental analysis, MS, IR, 1H- NMR and 13C- NMR spectroscopy. The obtained results showed that the ligands are bidentate, coordinated to the copper(II) over N, S- donor atoms. The test in vitro antibacterial activities of the ligands and their complexes against three of positive bacteria types: Lactobacillus fermentum, Bacillus subtilis, Staphylococcus aureus and three of negative bacteria types: Salmonella enterica, Escherichia coli, Pseudomonas aeruginosa and one type of fungus: Candida albican show that Cu(L2)2 againt 3/7 bacteria and fungus type.

Phương pháp sắc kí lỏng hiệu năng cao với detector mảng diode được phát triển để xác định hàm lượngdiquat trong mẫu huyết tương người. Các điều kiện sắc ký thích hợp: pha tĩnh là cột C8, pha động là hỗn hợp dung dịch đệm axetonitril và axit orthophosphoric / dihydroclorua (pH 2,5), tốc độ dòng 0,5 mL/phút, bước sóng phát hiện là 309 nm và thời gian lưu của diquat là 10,03 phút. Khoảng tuyến tính của phương pháp từ 0,5 đến 10 µg/mL, giới hạn phát hiện 0,1 µg/mL, giới hạn định lượng 0,35 µg/mL. Phương pháp đã được phát triển và áp dụng để xác định mẫu huyết tương bệnh nhân ngộ độc diquat tại Trung tâm Chống Độc, Bệnh viện Bạch Mai

This study focuses on the formulation of the extraction, isolation and purification ergosterol process from C. faveomaculata. The structure of ergosteterol determined based on the data of spectrum(melting point, IR, MS, and NMR spectrum). Furthermore, a standard HPLC method for determining quality and quantities of ergosterol was established in this study. The results in this study showed that the prepared standard Ergosterol sample qualifies all evaluative standards. Moreover, at two independent laboratories up to ISO / GLP standards also revealed the standards are high quality, reliable, and eligible for registration of national standards.

From stems and leaves of Stixis scandens, compounds were successfully isolated including: icariside B1 (1), bergenin (2), icariside B5 (3), benzyl alcohol β-D-glucopyranoside (4), adenosine (5), cis-syringin (6), ginsenoside Rg1 (7), lyoniresinol 3α-O-β-D-glucopyranoside (8). The identification of the chemical structure of these compounds was established via analysis of their nuclear magnetic resonance (NMR) spectra alongside a comparative examination of published literature regarding such spectra. These compounds were first reported in Stixis scandes. The isolated compounds were evaluated for their inhibitory effects on nitric oxide production in lipopolysaccharide-induced RAW264.7 cells

Hầm biogas hộ gia đình ở nông thôn Việt Nam đã chứng minh hiệu quả xử lý chất thải chăn nuôi nhất định, đồng thời tạo ra nhiên liệu khí sinh học cho các hộ gia đình. Để đánh giá hoạt động của hầm biogas xử lý chất thải nuôi heo cũng như khả năng xử lý kết hợp với chất thải sinh hoạt từ các hộ gia đình, nghiên cứu đã thực hiện trên hầm biogas trong thực tế có thể tích 6m3. Khảo sát được thực hiện trong 3 giai đoạn chạy tại đó, giai đoạn 1 và giai đoạn 2 hầm biogas chỉ xử lý phân lợn ở các tải trọng khác nhau, và ở giai đoạn 3, chất thải sinh hoạt hữu cơ được bổ sung để tăng tải trọng hệ thống lên 10% so với chế độ 2. Kết quả cho thấy, hầm hoạt động ổn định trong 60 ngày khảo sát ở giai đoạn 3, không chỉ cho lượng khí sinh ra cao hơn 58% mà còn có năng suất sinh khí riêng (m3 mê tan/kgVS) cao hơn 39% so với chế độ không bổ sung chất thải rắn. Nước thải sau xử lý có hàm lượng COD trung bình 1588 mg/L, cần được xử lý trước khi thải ra môi trường.

   The steam distillated essential oils of Cymbopogon citratus collected in Son Hung, Thanh Son, Phu Tho were analyzed for physiochemical properties and chemical composition. The cytotoxic activity of the essential oils was evaluated against human hepatocarcinoma Hep3B cell line. Key words: Lemongrass essential oil, chemical composition, cytotoxicity

Concentrations of eight metals (Cd, As, Cr, Co, Cu, Pb, Zn, Ni) in PM2.5 were examined in a suburban area (Dong Anh) and residential urban area (Thanh Xuan) in Hanoi in winter and spring. The results revealed that higher metals in PM2.5 were observed in winter in Dong Anh, while higher metals in PM2.5 were observed in spring in Thanh Xuan due to the different sources at study area. The concentrations of Cu, Pb, Zn, Cd, Cu and As in PM2.5 in Dong Anh were higher than those in Thanh Xuan due to the heavy vehicle, activities industrial production and craft village, which increases emissions into atmospheric. Concentration of Cd, V, Ni, Pb, Mn and Cr in PM2.5 were lower than the allowable values according to EU and WHO standards. The enrichment factor analysis shows that the emission source EF of these metals were related to human activities (traffic, industry, or craft villages). The health risk assessments suggested that As (HQ = 1.1) and Cd (HQ = 1.0) in Thanh Xuan, and As (HQ = 1.6) and Cd (HQ = 1.8) in Dong Anh had non-carcinogenic risks for adults. The cumulative carcinogenic risk of elements was within the acceptable range for both children and adults at both sites.

   Manganese ferrite nanoparticles (MnFe2O4) were prepared by solution combustionmethod using urea as fuel. The products were characterized by X-ray Diffraction(XRD), Scanning Electron Microscopy (SEM), Transnission Electron Microscopy(TEM), Brunauer- Emmett-Teller (BET). The obtained results showed that theproducts have mesoporous structure with high surface area and nanocrystallinestructure. The MnFe2O4 nanoparticle obtained by solution combustion method has theaverage particle size under 30 nm. The catalytic activities of MnFe2O4 nanoparticleswere investigeted using aqueous solution of methylene blue.Keyword: MnFe2O4, solution combustion method, catalytic, methylene blue.

   The ligand 2 - acetylpyridine thiosemicarbazone (Hthacpyr) was synthesised from thereaction of 2 - acetylpyridine and thiosemicarbazide. It reacts with zinc nitrates, in theabsence of ammonia to form Zn(thacpyr)2. Structure and spectroscopic of ligand andits complex has been studied. The result of methods: IR, 1H -NMR, 13C -NMR, MS andX -ray diffraction show that in the complex, ligand was deprotonated and behaved astridentate ligand, bonding to Zn(II) via N(1), Npyridineand S donor atoms. Theantimicrobial, antifungal of the ligand and its complex has also been investigated. Thebiological activity of the complexe was higher than that of the free ligand.Keywords: Ligand, 2 - acetylpyridine thiosemicarbazone, complexe, ligand,antimicrobial and antifungal.