Pub Date : 2022-11-28DOI: 10.25073/2588-1140/vnunst.5286
N. Nhan, Vu Anh Duc, Mai Xuân Dũng, Hoàng Quang Bắc
Water-soluble CdTe quantum dots (QDs) have been utilized as photoluminescence probes for the detection of metal ions such as Pb2+, Hg2+, Cd2+, etc. We initially developed highly photoluminescence (PL) Zn-doped CdTe for toxic ions detection. A study on the changes of optical properties of Zn-doped CdTe and CdTe QDs when exposed to Pb2+ suggested that Pb2+ could act as a surface passivating agent to reduce Te2- dangling bonds while Zn2+ dopant stabilizes the QDs surface against ambient oxidation. The results demonstrated herein provide useful understandings of the interactions between water-soluble QDs and metal ions. These results suggest further applications of QDs in sensing metal ions.
{"title":"Effects of Zn (II) on the Optical Properties of CdTe Quantum Dots and Their Photoluminescence Response to Lead Ion","authors":"N. Nhan, Vu Anh Duc, Mai Xuân Dũng, Hoàng Quang Bắc","doi":"10.25073/2588-1140/vnunst.5286","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5286","url":null,"abstract":"Water-soluble CdTe quantum dots (QDs) have been utilized as photoluminescence probes for the detection of metal ions such as Pb2+, Hg2+, Cd2+, etc. We initially developed highly photoluminescence (PL) Zn-doped CdTe for toxic ions detection. A study on the changes of optical properties of Zn-doped CdTe and CdTe QDs when exposed to Pb2+ suggested that Pb2+ could act as a surface passivating agent to reduce Te2- dangling bonds while Zn2+ dopant stabilizes the QDs surface against ambient oxidation. The results demonstrated herein provide useful understandings of the interactions between water-soluble QDs and metal ions. These results suggest further applications of QDs in sensing metal ions.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87108993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-28DOI: 10.25073/2588-1140/vnunst.5089
N. T. Uyen, N. Thanh, W. Fang, D. Truong
We here report Primulina jingxiensis (Yan Liu, W. B. Xu, H. S. Gao) W. B. Xu, K. F. Chung as a new record and confirmed the occurrence of Loxostigma dongxingensis (Chun ex K. Y. Pan) Mich. Möller, H. Atkins for the flora of Vietnam which have been still known endemically to southern China from the previous treatments. Detailed morphological description as Herbs perennial, stemless. Leaves basal, carnose, blades obovate or elliptic to suborbicular, densely villous, thickened, papery when dry, base attenuate to cuneate, apex obtuse to subrounded, margin subentire, lateral veins 2 or 3, inconspicuous. Cymes lax, axillary, 2-5 cymes, 2-4-branched, each 1-3-flowered: bracts 2, opposite, margin entire, pubescent. In addition to the description as color illustrations together with information on distribution, habitat, phenology, and taxonomic notes of these two species are also given.
本文报道了报春花jingxiensis(刘岩，许文斌，高洪生)许文斌，钟国峰为新记录，并证实了loxo柱头dongxingensis (Chun ex k.y. Pan)的存在。Möller, H. Atkins为越南的植物群，这些植物群在以前的处理中仍然是中国南方特有的。详细的形态描述为多年生草本，无茎。叶基生，肉鼻，叶片倒卵形或椭圆形到近圆形，密被长柔毛，加厚，干燥时，基部渐狭到楔形，先端钝到近圆形，边缘近全缘，侧脉2或3，不明显。聚伞花序松弛，腋生，2-5聚伞花序，2-4分枝，每1-3花;苞片2，对生，边缘全缘，短柔毛。文中除了以彩色插图描述外，还提供了两种植物的分布、栖息地、物候和分类注释等信息。
{"title":"Primulina jingxiensis, a New Record and Confirmation of Loxostigma dongxingensis for the Flora of Vietnam","authors":"N. T. Uyen, N. Thanh, W. Fang, D. Truong","doi":"10.25073/2588-1140/vnunst.5089","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5089","url":null,"abstract":"We here report Primulina jingxiensis (Yan Liu, W. B. Xu, H. S. Gao) W. B. Xu, K. F. Chung as a new record and confirmed the occurrence of Loxostigma dongxingensis (Chun ex K. Y. Pan) Mich. Möller, H. Atkins for the flora of Vietnam which have been still known endemically to southern China from the previous treatments. Detailed morphological description as Herbs perennial, stemless. Leaves basal, carnose, blades obovate or elliptic to suborbicular, densely villous, thickened, papery when dry, base attenuate to cuneate, apex obtuse to subrounded, margin subentire, lateral veins 2 or 3, inconspicuous. Cymes lax, axillary, 2-5 cymes, 2-4-branched, each 1-3-flowered: bracts 2, opposite, margin entire, pubescent. In addition to the description as color illustrations together with information on distribution, habitat, phenology, and taxonomic notes of these two species are also given.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90979740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-27DOI: 10.25073/2588-1140/vnunst.5310
D. Sang
Hoa Binh, situated in one of the Vietnam’s biodiversity areas, has four nature reserves (Ngoc Son-Ngo Luong, Hang Kia-Pa Co, Phu Canh, and Thuong Tien nature reserves), and also shares a part of Cuc Phương and Ba Vi National Parks, as well as having many different types of habitats. However, information on the terrestrial molluscs’ biodiversity is limited. This study provides an up-to-date checklist of terrestrial molluscs species found on five habitats in Hoa Binh Province. A total of 104 species representing 60 genera and 21 families is enumerated based on systematic field surveys of 49 sampling plots. Eight of these were new records for Hoa Binh Province: Dicharax fraterculus, Rhaphaulus tonkinensis, Tortaxis pilsbryi, Deroceras laeve, Parmarion martensi, Entadella concave, Meghimatium bilineatum, and Meghimatium pictum. Forests over limestone and isolated hills in Hoa Binh Province are rich in terrestrial molluscs. In the study area, several genera (Dicharax, Cyclophorus, Diplommatina, Pupina, Oospira and Haploptychius) are restricted to limestone mountains.
{"title":"Research on Species Composition of Terrestrial Molluscs (Mollusca: Gastropoda) in Hoa Binh Province","authors":"D. Sang","doi":"10.25073/2588-1140/vnunst.5310","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5310","url":null,"abstract":"Hoa Binh, situated in one of the Vietnam’s biodiversity areas, has four nature reserves (Ngoc Son-Ngo Luong, Hang Kia-Pa Co, Phu Canh, and Thuong Tien nature reserves), and also shares a part of Cuc Phương and Ba Vi National Parks, as well as having many different types of habitats. However, information on the terrestrial molluscs’ biodiversity is limited. This study provides an up-to-date checklist of terrestrial molluscs species found on five habitats in Hoa Binh Province. A total of 104 species representing 60 genera and 21 families is enumerated based on systematic field surveys of 49 sampling plots. Eight of these were new records for Hoa Binh Province: Dicharax fraterculus, Rhaphaulus tonkinensis, Tortaxis pilsbryi, Deroceras laeve, Parmarion martensi, Entadella concave, Meghimatium bilineatum, and Meghimatium pictum. Forests over limestone and isolated hills in Hoa Binh Province are rich in terrestrial molluscs. In the study area, several genera (Dicharax, Cyclophorus, Diplommatina, Pupina, Oospira and Haploptychius) are restricted to limestone mountains.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81424036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-24DOI: 10.25073/2588-1140/vnunst.5342
Nguyen Hung Huy, N. Huy, T. T. Nguyet, Pham Chien Thang
The ligand picolinoyl(4-ethylthiosemicarbazide) HL was synthesized by the reaction of picolinohydrazide and ethyl isothiocyanate in absolute ethanol. The structure of HL was characterized by spectroscopic methods such as IR, 1H, and 13C NMR spectroscopy. One-pot reaction of CuCl2 and equimolar amounts of HL and o-phenanthroline in CH2Cl2/MeOH mixture with the presence of a supporting base like pyridine gave rise to a new heteroleptic cationic Cu(II) complex with the composition of [Cu(L)(o-phen)]+. Crystalline PF6– salt was obtained after workup with (n-Bu4N)(PF6) and single-crystal structure of the complex was determined. The spectroscopic data and X-ray crystallography demonstrated that the Cu(II) ion is five-coordinate with the coordination sphere consisted of (S, N1, Npyridine) and (N, N) donor sets belonging to the singly deprotonated ligand {L–} and o-phenanthroline, respectively.
{"title":"Synthesis and Structural Characterization of Picolinoyl (4-ethylthiosemicarbazide) and its New Heteroleptic Cu(II) Complex","authors":"Nguyen Hung Huy, N. Huy, T. T. Nguyet, Pham Chien Thang","doi":"10.25073/2588-1140/vnunst.5342","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5342","url":null,"abstract":"The ligand picolinoyl(4-ethylthiosemicarbazide) HL was synthesized by the reaction of picolinohydrazide and ethyl isothiocyanate in absolute ethanol. The structure of HL was characterized by spectroscopic methods such as IR, 1H, and 13C NMR spectroscopy. One-pot reaction of CuCl2 and equimolar amounts of HL and o-phenanthroline in CH2Cl2/MeOH mixture with the presence of a supporting base like pyridine gave rise to a new heteroleptic cationic Cu(II) complex with the composition of [Cu(L)(o-phen)]+. Crystalline PF6– salt was obtained after workup with (n-Bu4N)(PF6) and single-crystal structure of the complex was determined. The spectroscopic data and X-ray crystallography demonstrated that the Cu(II) ion is five-coordinate with the coordination sphere consisted of (S, N1, Npyridine) and (N, N) donor sets belonging to the singly deprotonated ligand {L–} and o-phenanthroline, respectively.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89796840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-25DOI: 10.25073/2588-1140/vnunst.4966
N. Anh, Trần Huỳnh Bảo Châu, Nguyen Phuoc Khai Hoan, T. Hiếu
In order to develop high-performance subunit vaccines, many studies are currently aiming at the development of immunoadjuvants. Flagellin protein (FliC) contained in the Salmonella’s filament is one of the potential candidates for this purpose. However, the high antigenic property of FliC has made it difficult to apply for many vaccines. A variant with the deletion of amino acids from 220 to 320 of flagellin has been proven to have an adjuvant effect with lower immunogenicity. In this present study, we cloned and expressed FliCD220-320 recombinant in Escherichia coli system. The expression of FliCΔ220-320 was induced by IPTG and confirmed by SDS-PAGE and Western Blot probed with 6xHis tag antibody. Results showed that most of the expressed protein is insoluble. The targeted protein was then solubilized, re-folded and purified by affinity chromatography method with the purity of 80 %. With these results, we successfully expressed FliCD220-320 recombinant protein and this is a source for the evaluation and development of immune adjuvants.
{"title":"Cloning, Expression, Re-folding, and Purification of Protein Flic (salmonella Enteritidis) with Deletion of Amino Acids 220-320","authors":"N. Anh, Trần Huỳnh Bảo Châu, Nguyen Phuoc Khai Hoan, T. Hiếu","doi":"10.25073/2588-1140/vnunst.4966","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.4966","url":null,"abstract":"In order to develop high-performance subunit vaccines, many studies are currently aiming at the development of immunoadjuvants. Flagellin protein (FliC) contained in the Salmonella’s filament is one of the potential candidates for this purpose. However, the high antigenic property of FliC has made it difficult to apply for many vaccines. A variant with the deletion of amino acids from 220 to 320 of flagellin has been proven to have an adjuvant effect with lower immunogenicity. In this present study, we cloned and expressed FliCD220-320 recombinant in Escherichia coli system. The expression of FliCΔ220-320 was induced by IPTG and confirmed by SDS-PAGE and Western Blot probed with 6xHis tag antibody. Results showed that most of the expressed protein is insoluble. The targeted protein was then solubilized, re-folded and purified by affinity chromatography method with the purity of 80 %. With these results, we successfully expressed FliCD220-320 recombinant protein and this is a source for the evaluation and development of immune adjuvants.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82411539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-19DOI: 10.25073/2588-1140/vnunst.5307
V. Lien, N. T. Cuong, D. T. Hoa
This study was conducted to assess the resources of oil plants in Xuan Nha special-use forest, Son La province. The survey period was conducted from July 2018 to June 2021. The results showed that there were 317 species, 196 genera of 62 families belonging to Pinophyta and Magnoliophyta. In addition to the value for essential oils, many species had other values such as 256 medicinal species, 105 edible species, 66 timber species, 35 bonsai species, 20 wine additive species, 9 species used for animal feeds, 7 dye-containing species and 3 poisonous species. The spectrum of life forms of identified species included: SB = 63.41Ph + 11.99 Th + 11.04Cr + 7.57Hm + 5.99 Ch. We have identified 24 species of plants as being endangered in the Vietnam Red Book (2007), 12 species listed in the Governmental Decree and 10 species in the red list of IUCN (2021). These are species with a small number of individuals that need to have policies for conservation and development.
{"title":"Species Composition and Utilization Values of Oil Plants in Xuan Nha Special-use Forest, Son La Provine","authors":"V. Lien, N. T. Cuong, D. T. Hoa","doi":"10.25073/2588-1140/vnunst.5307","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5307","url":null,"abstract":"This study was conducted to assess the resources of oil plants in Xuan Nha special-use forest, Son La province. The survey period was conducted from July 2018 to June 2021. The results showed that there were 317 species, 196 genera of 62 families belonging to Pinophyta and Magnoliophyta. In addition to the value for essential oils, many species had other values such as 256 medicinal species, 105 edible species, 66 timber species, 35 bonsai species, 20 wine additive species, 9 species used for animal feeds, 7 dye-containing species and 3 poisonous species. The spectrum of life forms of identified species included: SB = 63.41Ph + 11.99 Th + 11.04Cr + 7.57Hm + 5.99 Ch. We have identified 24 species of plants as being endangered in the Vietnam Red Book (2007), 12 species listed in the Governmental Decree and 10 species in the red list of IUCN (2021). These are species with a small number of individuals that need to have policies for conservation and development.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79591281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-15DOI: 10.25073/2588-1140/vnunst.5261
Nguyen Van Hieu, Lai Viet Hung, P. V. Truong, Dang Minh Tu, P. Huyen, N. Q. Nga, P. T. Ngoc, N. Khoi, V. Trung, Nguyen Hoang Hao, Tran Van Mui
The genus Uvaria Juss. is distinguished other genus of Annonaceae especially: Stellate or caespitose hairs, flowers bisexual opposite to leaves, flower are solitary or cymose. Sepal 3, valvate,… Uvaria clementis (Merr.) Attan., I.M. Turn&R.M.K Saunders distributed from Malaysia, Indonesia, Brunei to Thailan, Campuchia,… The specimen which collected at Dongnai province and saved at The Hebarium National Instiute of Medicinal Materialis is newly recorded for the flora of Vietnam. This study, we are described, illustrated and notes on taxonomy of Uvaria clementis Teaching and scientific research are two main.
{"title":"Uvaria clementis (Merr.) Attan., I. M. Turner and R. M. K. Saunders (Annonaceae), a New Record for the Flora of Vietnam","authors":"Nguyen Van Hieu, Lai Viet Hung, P. V. Truong, Dang Minh Tu, P. Huyen, N. Q. Nga, P. T. Ngoc, N. Khoi, V. Trung, Nguyen Hoang Hao, Tran Van Mui","doi":"10.25073/2588-1140/vnunst.5261","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5261","url":null,"abstract":"The genus Uvaria Juss. is distinguished other genus of Annonaceae especially: Stellate or caespitose hairs, flowers bisexual opposite to leaves, flower are solitary or cymose. Sepal 3, valvate,… Uvaria clementis (Merr.) Attan., I.M. Turn&R.M.K Saunders distributed from Malaysia, Indonesia, Brunei to Thailan, Campuchia,… The specimen which collected at Dongnai province and saved at The Hebarium National Instiute of Medicinal Materialis is newly recorded for the flora of Vietnam. This study, we are described, illustrated and notes on taxonomy of Uvaria clementis Teaching and scientific research are two main.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86507593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-12DOI: 10.25073/2588-1140/vnunst.5365
P. Yen, D. T. Hang, N. Hoang, Ngo Anh Bang, Duong Thi Hai Yen, N. A. Hung, N. Thanh, B. H. Tai, N. X. Nhiem, P. Kiem
Seven known lignans, tortoside A (1), (+)-syringaresinol (2), (+)-medioresinol (3), (+)-pinoresinol (4), (+)-lyoniresin-6-yl β-D-glucopyranoside (5), (-)-lyoniresinol 3α-O-β-D-glucopyranoside (6), and (-)-lyoniresinol (7) were isolated from the leaves of Gymnema sylvestre (Retz.) R.Br. ex Schult. Their structures were identified on the basis of spectroscopic evidence and in comparison with those reported in the literature. All compounds were reported from G. sylvestre for the first time.
从木本藤(Gymnema sylvestre, Retz)叶中分离得到7种已知木脂素，分别为:陆甲苷A(1)、(+)-丁香脂醇(2)、(+)-中脂醇(3)、(+)-松脂醇(4)、(+)-松脂醇-6-基β- d -葡萄糖苷(5)、(-)-松脂醇3α- o -β- d -葡萄糖苷(6)和(-)-松脂醇(7)。R.Br。Schult交货。根据光谱证据并与文献报道的结构进行了比较，确定了它们的结构。所有化合物均为首次从该植物中分离得到。
{"title":"Lignans from Gymnema Sylvestre","authors":"P. Yen, D. T. Hang, N. Hoang, Ngo Anh Bang, Duong Thi Hai Yen, N. A. Hung, N. Thanh, B. H. Tai, N. X. Nhiem, P. Kiem","doi":"10.25073/2588-1140/vnunst.5365","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5365","url":null,"abstract":"Seven known lignans, tortoside A (1), (+)-syringaresinol (2), (+)-medioresinol (3), (+)-pinoresinol (4), (+)-lyoniresin-6-yl β-D-glucopyranoside (5), (-)-lyoniresinol 3α-O-β-D-glucopyranoside (6), and (-)-lyoniresinol (7) were isolated from the leaves of Gymnema sylvestre (Retz.) R.Br. ex Schult. Their structures were identified on the basis of spectroscopic evidence and in comparison with those reported in the literature. All compounds were reported from G. sylvestre for the first time.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78250625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-12DOI: 10.25073/2588-1140/vnunst.5485
Quoc Anh Hoang, Pham Dang Minh, Tran Cong Quyet, T. Tri, T. Minh, Shin Takahashi
In this study, a rapid analytical method was developed and validated for the determination of polybrominated diphenyl ethers PBDEs in house dust samples. The dust sample was solvent extracted by using a focused ultrasonic processor with reduced extraction time (total 30 min/sample) and solvent volume (about 30 mL/sample). The crude extract was purified by passing through a self-packed multilayer column containing 44% sulfuric acid impregnated silica gel, Florisil, and anhydrous sodium sulfate. PBDEs were eluted from the clean-up column by a mixture of dichloromethane in hexane (1:3,…). PBDEs (41 mono- to deca-BDE congeners) were analyzed by using gas chromatography/mass spectrometry (GC/MS) with negative chemical ionization (NCI) and selected ion monitoring (SIM) mode. The analytical method was validated by using procedural blank, matrix-spike, and standard reference material (SRM) samples. Recoveries of PBDEs in spiked samples ranged from 65% to 120%. Analytical results of the SRM 2585 (Organic Contaminants in House Dust, National Institute of Standards and Technology, USA) indicate method accuracy with ratios of measured to certified values of almost compounds ranging from 76% to 110%. All the experiments were conducted in duplicate, showing acceptable repeatability (RSD < 15%). This method can be applied for simultaneous determination of mono- to deca-BDE congeners in dust samples at ppb to ppm levels with several advantages such as simple, rapid, accurate, cost-effective, and reducing amounts of chemicals and solvents.
{"title":"Development and Validation of a Rapid Analytical Method for Polybrominated Diphenyl Ethers in House Dust","authors":"Quoc Anh Hoang, Pham Dang Minh, Tran Cong Quyet, T. Tri, T. Minh, Shin Takahashi","doi":"10.25073/2588-1140/vnunst.5485","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5485","url":null,"abstract":"In this study, a rapid analytical method was developed and validated for the determination of polybrominated diphenyl ethers PBDEs in house dust samples. The dust sample was solvent extracted by using a focused ultrasonic processor with reduced extraction time (total 30 min/sample) and solvent volume (about 30 mL/sample). The crude extract was purified by passing through a self-packed multilayer column containing 44% sulfuric acid impregnated silica gel, Florisil, and anhydrous sodium sulfate. PBDEs were eluted from the clean-up column by a mixture of dichloromethane in hexane (1:3,…). PBDEs (41 mono- to deca-BDE congeners) were analyzed by using gas chromatography/mass spectrometry (GC/MS) with negative chemical ionization (NCI) and selected ion monitoring (SIM) mode. The analytical method was validated by using procedural blank, matrix-spike, and standard reference material (SRM) samples. Recoveries of PBDEs in spiked samples ranged from 65% to 120%. Analytical results of the SRM 2585 (Organic Contaminants in House Dust, National Institute of Standards and Technology, USA) indicate method accuracy with ratios of measured to certified values of almost compounds ranging from 76% to 110%. All the experiments were conducted in duplicate, showing acceptable repeatability (RSD < 15%). This method can be applied for simultaneous determination of mono- to deca-BDE congeners in dust samples at ppb to ppm levels with several advantages such as simple, rapid, accurate, cost-effective, and reducing amounts of chemicals and solvents.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86135944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-22DOI: 10.25073/2588-1140/vnunst.5186
N. Nghia, Pham Manh Thao, Nguyên Van Ky, Ngo Quy Quyen, P. D. Long, D. Chien, Nguyen Si Hieu
In this work, NaNi0.5Ti0.5O2 cathode materials of sodium ion batteries were synthesized by a pre-milling combined with solid-state reaction method using sodium hydroxide (NaOH), nickel (II) acetate (2(CH3COO)Ni.4H2O), and titanium dioxide (TiO2) as the precursors. Results of X-ray diffraction analysis of the materials obtained after the milling and calcination processes revealed that the increment of the pre-milling time improved the reactivity of NaOH and TiO2, thereby significantly reduced the content of NiO impurity in the NaNi0.5Ti0.5O2 product. The as-synthesized cathode material possessed an excellent electrochemical performance with 77% capacity (compared to the second cycle) retained after 50 cycles of charge/discharge, and 60% capacity retention when the rate of charge/discharge increased from 0.5 to 8 C.
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