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1.
《Journal of separation science》2018,41(7):1524-1531
Nanoliter high‐performance liquid chromatography shows low consumption of solvents and samples, offering one of the best choices for arsenic speciation in precious samples in combination with inuctively coupled plasma mass spectrometry. A systematic investigation on coupling nanoliter high‐performance liquid chromatography to inductively coupled plasma mass spectrometry from instrument design to injected sample volume and mobile phase was performed in this study. Nanoflow mobile phase was delivered by flow splitting using a conventional high‐pressure pump with reuse of mobile phase waste. Dead volume was minimized to 60 nL for the sheathless interface based on the previously developed nanonebulizer. Capillary columns for nanoliter high‐performance liquid chromatography were found to be sensitive to sample loading volume. An apparent difference was also found between the mobile phases for nanoliter and conventional high‐performance liquid chromatography. Baseline separation of arsenite, arsenate, monomethylarsenic, and dimethylarsenic was achieved within 11 min on a 15 cm C18 capillary column and within 12 min on a 25 cm strong anion exchange column. Detection limits of 0.9–1.8 μg/L were obtained with precisions variable in the range of 1.6–4.2%. A good agreement between determined and certified values of a certified reference material of human urine (GBW 09115) validated its accuracy along with good recoveries (87–102%). 相似文献
2.
Dr. Oliver Hegen Jens Braese Prof. Dr. Alexey Y. Timoshkin Prof. Dr. Manfred Scheer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(2):485-489
A new class of neutral bidentate ligands with pnictogenyl-functional sites has been obtained. The reaction of tmeda⋅(BH2I)2 ( 1 , tmeda=tetramethylethylendiamine) with different phosphanides yields the corresponding bidentate phosphanylboranes tmeda⋅(BH2PH2)2 ( 2 a ), tmeda⋅(BH2PPh2)2 ( 2 b ), and tmeda⋅(BH2tBuPH)2 ( 2 c ). This reaction strategy could be further extended to synthesize the first bidentate arsanylborane tmeda⋅(BH2AsPh2)2 ( 3 ). Depending on the substituents on the phosphorus, these compounds form different AuI complexes, to build either polymeric tmeda⋅(BH2PH2AuCl)2 ( 4 a ), or monomeric tmeda⋅(BH2PPh2AuCl)2 ( 4 b ) products. These compounds form also neutral oligomeric group 13/15 chain-like molecules by coordination to a boron moiety such as tmeda⋅(BH2PH2BH3)2 ( 5 a ) and tmeda⋅(BH2AsPh2BH3)2 ( 5 b ). DFT calculations provide insight into the differences between the syntheses of mono- and bidentate pnictogenylboranes. 相似文献
3.
4.
采用电感耦合等离子体质谱法(ICP-MS)测定食用植物油中铅(Pb)、总砷(As)含量,对测定结果的不确定度进行评定。利用ICP-MS,采用标准加入法测定食用植物油中Pb,As含量,分析测定过程中不确定度来源,包括样品称量、定容、前处理、溶液中Pb和As浓度、重复性测量等引入的不确定度,计算合成不确定度。结果表明,Pb含量为(0.0228±0.013) mg/kg,k=2;As含量为(0.00785±0.0045) mg/kg,k=2。该方法的不确定度主要来源于样品溶液中的Pb,As浓度,评定得到的不确定度可为正确评价测定结果提供科学依据。 相似文献
5.
Dr. Mahendra K. Sharma Dr. Sebastian Blomeyer Beate Neumann Dr. Hans-Georg Stammler Priv.-Doz. Dr. Rajendra S. Ghadwal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(35):8249-8253
The first divinyldiarsenes [{(NHC)C(Ph)}As]2 (NHC=IPr 3 a , SIPr 3 b ; IPr=C{(NAr)CH}2; SIPr=C{(NAr)CH2}2; Ar=2,6-iPr2C6H3) are reported. Compounds 3 a and 3 b were prepared by the reduction of corresponding chlorides {(NHC)C(Ph)}AsCl2 (NHC=IPr 2 a , SIPr 2 b ) with Mg. Calculations revealed a small HOMO–LUMO energy gap of 3.86 ( 3 a ) and 4.24 eV ( 3 b ). Treatment of 3 a with (Me2S)AuCl led to the cleavage of the As=As bond to restore 2 a , which is expected to proceed via the diarsane [{(IPr)C(Ph)}AsCl]2 ( 4 ). Remarkably, 4 as well as 2 a can be selectively accessed on treatment of 3 a with an appropriate amount of C2Cl6. Moreover, 3 a readily reacts with PhEEPh (E=Se or Te) at room temperature to give {(IPr)C(Ph)}As(EPh)2 (E=Se 5 a ; Te 5 b ), revealing the cleavage of As=As and E−E bonds and the formation of As−E bonds. Such highly selective stepwise oxidation ( 3 a → 4 → 2 a ) and bond metathesis ( 3 a → 5 a , b ) reactions are unprecedented in main-group chemistry. 相似文献
6.
Dr. Darren M. C. Ould Dr. Rebecca L. Melen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(44):9835-9845
The past 20 years has seen significant advances in main group chemistry and their use in catalysis. This Minireview showcases the recent emergence of phosphorus and arsenic containing heterocycles as catalysts. With that, we discuss how the Group 15 compounds diazaphospholenes, diazaarsolenes, and their cationic counterparts have proven to be highly effective catalysts for a wide range of reduction transformations. This Minireview highlights how the initial discovery by Gudat of the hydridic nature of the P−H bond in these systems led to these compounds being used as catalysts and discusses the wide range of examples currently present in the literature. 相似文献
7.
建立氢化物发生–原子吸收光谱法联用测定铅粉中痕量砷、锑的方法。试样用稀硝酸溶解,用5%抗坏血酸溶液作为砷(Ⅴ)、锑(Ⅴ)的预还原剂,5%的硫脲溶液作为其它元素的掩蔽剂,选用1%硼氢化钠溶液作为还原剂,氢化物反应在10%盐酸介质中进行。在优化的试验条件下,砷、锑的质量浓度在0~20 ng/m L范围内与吸光度线性相关,相关系数r2分别为砷0.999 6,锑0.993 8,方法的检出限分别为砷0.40 ng/m L,锑0.75 ng/m L。砷、锑测定结果的相对标准偏差分别为4.96%,6.27%(n=6),铅粉样品加标回收率分别为砷87.6%,锑79.3%。该方法准确可靠,可用于测定铅粉中痕量砷、锑。 相似文献
8.
Dr. Benedict M. Gardner Dr. Gábor Balázs Prof. Dr. Manfred Scheer Dr. Ashley J. Wooles Dr. Floriana Tuna Prof. Eric J. L. McInnes Dr. Jonathan McMaster Dr. William Lewis Prof. Dr. Alexander J. Blake Prof. Dr. Stephen T. Liddle 《Angewandte Chemie (International ed. in English)》2015,54(50):15250-15254
The HAsAsH molecule has hitherto only been proposed tentatively as a short‐lived species generated in electrochemical or microwave‐plasma experiments. After two centuries of inconclusive or disproven claims of HAsAsH formation in the condensed phase, we report the isolation and structural authentication of HAsAsH in the diuranium(IV) complex [{U(TrenTIPS)}2(μ‐η2:η2‐As2H2)] ( 3 , TrenTIPS=N(CH2CH2NSiPri3)3; Pri=CH(CH3)2). Complex 3 was prepared by deprotonation and oxidative homocoupling of an arsenide precursor. Characterization and computational data are consistent with back‐bonding‐type interactions from uranium to the HAsAsH π*‐orbital. This experimentally confirms the theoretically predicted excellent π‐acceptor character of HAsAsH, and is tantamount to full reduction to the diarsane‐1,2‐diide form. 相似文献
9.
摘 要:采用微波消解-石墨炉原子吸收光谱法分析测定食用菌中总砷。取可食部分的食用菌粉碎均匀,采用微波消解对样品进行消解,将消解液于140℃赶酸至0.5mL ,用超纯水转移定容至25mL。以0.1%的硝酸钯为基体改进剂,塞曼扣背景,用石墨炉原子吸收光谱法测定总砷。方法检出限为0.4μg/L,线性范围为0~30 μg/L,线性相关系数(r)大于0.998,采用精密度考察方法重现性,不同浓度水平的RSD%均小于6.6%;三个浓度水平的加标回收率为80.6% ~ 103.9%,有证标准物质测定结果符合要求。实验结果表明,方法操作简便、灵敏、准确,适合食用菌中总砷的测定。对砷形态复杂的野生食用菌,微波消解后可直接采用石墨炉原子吸收光谱法测定总砷。 相似文献
10.
Dr. Dominik Raiser Dr. Klaus Eichele Dr. Hartmut Schubert Prof. Dr. Lars Wesemann 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(56):14073-14080
The reaction of the intramolecular germylene-phosphine Lewis pair (o-PPh2)C6H4GeAr* ( 1 ) with Group 15 element trichlorides ECl3 (E=P, As, Sb) was investigated. After oxidative addition, the resulting compounds (o-PPh2)C6H4(Ar*)Ge(Cl)ECl2 ( 2 : E=P, 3 : E=As, 4 : E=Sb) were reduced by using sodium metal or LiHBEt3. The molecular structures of the phosphine-stabilized phosphinidene (o-PPh2)C6H4(Ar*)Ge(Cl)P ( 5 ), arsinidene (o-PPh2)C6H4(Ar*)Ge(Cl)As ( 6 ) and stibinidene (o-PPh2)C6H4(Ar*)Ge(Cl)Sb ( 7 ) are presented; they feature a two-coordinate low-valent Group 15 element. After chloride abstraction, a cyclic germaphosphene [(o-PPh2)C6H4(Ar*)GeP] [B(C6H3(CF3)2)4] ( 8 ) was isolated. The 31P NMR data of the germaphosphene were compared with literature examples and analyzed by quantum chemical calculations. The phosphinidene was treated with [iBu2AlH]2, and the product of an Al−H addition to the low-valent phosphorus atom (o-PPh2)C6H4(Ar*)Ge(H)P(H)Al(C4H9)2 ( 9 ) was characterized. 相似文献