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1.
Analysis of inorganic ions in cerebrospinal fluid (CSF) is used mainly in the diagnostics of central nervous system diseases, such as Alzheimer’s disease or multiple sclerosis. A new analytical method for fast determination of inorganic cations (ammonium, calcium, magnesium, sodium and potassium) and anions (chloride, sulfate, nitrite and nitrate) in CSF on an electrophoretic microchip was developed in this context. Zone electrophoresis (ZE) separations were performed on the microchip with coupled channels (CC) and contact conductivity detection. Two different propionate background electrolytes were used for the sequential determination of cations at pH 3.1 and anions at pH 4.3. ZE was used for the determination of cationic constituents while ZE–ZE approach was employed for the determination of chloride in the first separation channel on the CC microchip and other anionic micro-constituents in the second channel. LOD values were in the range of 0.003–0.012 mg L−1 and 0.019–0.047 mg L−1 for cations and anions, respectively. Repeatability of migration time was up to 1.2 % for both cations and anions. Repeatability of peak area ranged from 0.3 to 5.6 % for cations and from 0.6 to 6.0 % for anions. Recovery of both cations and anions was in the range 90–106 %. CSF samples were only diluted appropriately without other sample pretreatment prior to analysis. Developed sequential method is suitable for fast determination of the studied cations and anions in CSF with total analysis time <15 min. 相似文献
2.
A novel dual-injection poly(methylmethacrylate) (PMMA) microchip electrophoretic system has been designed and fabricated for simultaneous measurements of anions and cations using a single channel and detection device. It consists of two sample reservoirs, on both sides of a common separation channel. Anions and cations can be simultaneously electrokinetically injected into both ends of the separation channel. Due to lower electroosmotic flow in polymer channels compared to glass ones, the cations and anions migrate in opposite directions and can be separated from each other and detected using a movable contactless conductivity detector (MCCD) positioned around the center of the separation channel. The effects of the detector position and of the separation voltage on the response and resolution have been studied and optimized for simultaneous determination of six low-energy explosive-related ions, including ammonium, methyl ammonium, sodium, chloride, nitrate, and perchlorate in a single analytical run (of ca. 3 min). Simultaneous detection of nerve-agent degradation products along with explosive-related anions and cations is also demonstrated. The versatile system can also be used for separately measuring anions or cations. The attractive behavior of the dual-opposite injection microchip offers great promise for a wide range of applications, including "total ion analysis" of various samples. 相似文献
3.
In the title compounds, C 7H 8NO 2+·NO 3−, (I), C 7H 8NO 2+·ClO 4−·H 2O, (II), and 2C 7H 8NO 2+·SO 42−, (III), the carboxyl planes of the 4‐carboxyphenylammonium cations are twisted from the aromatic plane. A homonuclear C(8) hydrogen‐bonding motif of 4‐carboxyphenylammonium cations is observed in both (I) and (II), leading to `head‐to‐tail' layers. The cations in (III) form carboxyl group dimers, making a graph‐set motif of R22(8). In all the structures, anions connect the cationic layers and an infinite chain running along the c axis is observed, having the C22(6) graph‐set motif. Interestingly, in (II), the anions are connected through weak hydrogen bonds involving the water molecules, leading to a graph‐set motif of R44(12). Alternate hydrophobic and hydrophilic layers are observed in all three compounds as a result of the column‐like arrangement of the aromatic rings of the cations and the anions. Furthermore, in (I), head‐to‐tail N—H⋯O interactions and interactions linking the cations and anions form an R64(16) hydrogen‐bonding motif, resulting in a pseudo‐inversion centre at (, , 0). 相似文献
4.
In strychninium 4‐chlorobenzoate, C 21H 23N 2O 2+·C 7H 4ClO 2−, (I), and strychninium 4‐nitrobenzoate, C 21H 23N 2O 2+·C 7H 4NO 4−, (II), the strychninium cations form pillars stabilized by C—H⋯O and C—H⋯π hydrogen bonds. Channels between the pillars are occupied by anions linked to one another by C—H⋯π hydrogen bonds. The cations and anions are linked by ionic N—H +⋯O − and C—H⋯ X hydrogen bonds, where X = O, π and Cl in (I), and O and π in (II). 相似文献
5.
In the salt 1‐methylpiperazine‐1,4‐diium bis(dihydrogen phosphate), C 5H 13N 22+·2H 2PO 4−, (I), and the solvated salt 2‐(pyridin‐2‐yl)pyridinium dihydrogen phosphate–orthophosphoric acid (1/1), C 10H 9N 2+·H 2PO 4−·H 3PO 4, (II), the formation of O—H...O and N—H...O hydrogen bonds between the dihydrogen phosphate (H 2PO 4−) anions and the cations constructs a three‐ and two‐dimensional anionic–cationic network, respectively. In (I), the self‐assembly of H 2PO 4− anions forms a two‐dimensional pseudo‐honeycomb‐like supramolecular architecture along the (010) plane. 1‐Methylpiperazine‐1,4‐diium cations are trapped between the (010) anionic layers through three N—H...O hydrogen bonds. In solvated salt (II), the self‐assembly of H 2PO 4− anions forms a two‐dimensional supramolecular architecture with open channels projecting along the [001] direction. The 2‐(pyridin‐2‐yl)pyridinium cations are trapped between the open channels by N—H...O and C—H...O hydrogen bonds. From a study of previously reported structures, dihydrogen phosphate anions show a supramolecular flexibility depending on the nature of the cations. The dihydrogen phosphate anion may be suitable for the design of the host lattice for host–guest supramolecular systems. 相似文献
6.
Bis(5‐chloro‐8‐hydroxyquinolinium) tetrachloridopalladate(II), (C 9H 7ClNO) 2[PdCl 4], (I), catena‐poly[dimethylammonium [[dichloridopalladate(II)]‐μ‐chlorido]], {(C 2H 8N)[PdCl 3]} n, (II), ethylenediammonium bis(5‐chloroquinolin‐8‐olate), C 2H 10N 22+·2C 9H 5ClNO −, (III), and 5‐chloro‐8‐hydroxyquinolinium chloride, C 9H 7ClNO +·Cl −, (IV), were synthesized with the aim of preparing biologically active complexes of Pd II and Ni II with 5‐chloroquinolin‐8‐ol (ClQ). Compounds (I) and (II) contain Pd II atoms which are coordinated in a square‐planar manner by four chloride ligands. In the structure of (I), there is an isolated [PdCl 4] 2− anion, while in the structure of (II) the anion consists of Pd II atoms, lying on centres of inversion, bonded to a combination of two terminal and two bridging Cl − ligands, lying on twofold rotation axes, forming an infinite [–μ 2‐Cl–PdCl 2–] n chain. The negative charges of these anions are balanced by two crystallographically independent protonated HClQ + cations in (I) and by dimethylammonium cations in (II), with the N atoms lying on twofold rotation axes. The structure of (III) consists of ClQ − anions, with the hydroxy groups deprotonated, and centrosymmetric ethylenediammonium cations. On the other hand, the structure of (IV) consists of a protonated HClQ + cation with the positive charge balanced by a chloride anion. All four structures are stabilized by systems of hydrogen bonds which occur between the anions and cations. π–π interactions were observed between the HClQ + cations in the structures of (I) and (IV). 相似文献
7.
The crystal structures of the title compounds, ( S)‐1‐carboxy‐3‐(methylsulfanyl)propanaminium chloride, C 5H 12NO 2S +·Cl −, and ( S)‐1‐carboxy‐3‐(methylselanyl)propanaminium chloride, C 5H 12NO 2Se +·Cl −, are isomorphous. The protonated l ‐methionine and l ‐selenomethionine molecules have almost identical conformations and create very similar contacts with the Cl − anions in the crystal structures of both compounds. The amino acid cations and the Cl − anions are linked viaN—H⋯Cl − and O—H⋯Cl − hydrogen bonds. 相似文献
8.
In the title compound, C 9H 18NO +·NO 3−, the piperidinium ring adopts a slightly deformed chair conformation and the nitrate anion is disordered. The ions are arranged in hydrogen‐bonded chains parallel to [001], in which the cations alternate with the anions. The intrachain hydrogen bonds are bifurcated and link the O atoms of the anions to the N atoms of the cations. 相似文献
9.
Analysis of inorganic ions in cerebrospinal fluid (CSF) is used mainly in the diagnostics of central nervous system diseases, such as Alzheimer’s disease or multiple sclerosis. A new analytical method for fast determination of inorganic cations (ammonium, calcium, magnesium, sodium and potassium) and anions (chloride, sulfate, nitrite and nitrate) in CSF on an electrophoretic microchip was developed in this context. Zone electrophoresis (ZE) separations were performed on the microchip with coupled channels (CC) and contact conductivity detection. Two different propionate background electrolytes were used for the sequential determination of cations at pH 3.1 and anions at pH 4.3. ZE was used for the determination of cationic constituents while ZE–ZE approach was employed for the determination of chloride in the first separation channel on the CC microchip and other anionic micro-constituents in the second channel. LOD values were in the range of 0.003–0.012 mg L ?1 and 0.019–0.047 mg L ?1 for cations and anions, respectively. Repeatability of migration time was up to 1.2 % for both cations and anions. Repeatability of peak area ranged from 0.3 to 5.6 % for cations and from 0.6 to 6.0 % for anions. Recovery of both cations and anions was in the range 90–106 %. CSF samples were only diluted appropriately without other sample pretreatment prior to analysis. Developed sequential method is suitable for fast determination of the studied cations and anions in CSF with total analysis time <15 min. 相似文献
10.
A method of ion-pair chromatography was developed on a reversed-phase silica-based monolithic column for the fast and simultaneous determination of trifluoromethanesulfonate (CF3SO3
−) and p-toluenesulfonate (C7H7SO3
−). The analysis was performed using a mobile phase of tetrabutylammonium hydroxide + citric acid + acetonitrile on the Chromolith Speed ROD RP-18e column with direct conductivity detection. The effects of the eluent, column temperature and flow rate on the retention of the anions were investigated. The experimental phenomenon was discussed according to hydrophobic interaction and ion-exchange mechanism in the separation. The optimized chromatographic conditions were selected. The optimized eluent for the separation consisted of 0.2 mmol L−1 tetrabutylammonium hydroxide + 0.10 mmol L−1 citric acid + 9% acetonitrile (pH 5.5). The flow rate was set at 6.0 mL min−1. The column temperature was 25 °C. Under the optimal conditions, the better separation of CF3SO3
− and C7H7SO3
− was achieved without any interference by other anions (Cl−, Br−, I−, NO3
−, SO4
2−, ClO3
−, BF4
− and PF6
−). The detection limit (S/N = 3) was 0.28 and 0.71 mg L−1 for CF3SO3
− and C7H7SO3
−, respectively. The method has been applied to the determination of CF3SO3
− and C7H7SO3
− in ionic liquids. The spiked recoveries of CF3SO3
− and C7H7SO3
− were 101.1 and 100.2%, respectively. 相似文献
11.
Crystals of the title compound, C 4H 8N 5+·C 2F 3O 2−, are built up of singly protonated 2,4‐diamino‐6‐methyl‐1,3,5‐triazin‐1‐ium cations and trifluoroacetate anions. The CF 3 group of the anion is disordered. The oppositely charged ions interact via almost linear N—H...O hydrogen bonds, forming a CF 3COO −...C 4H 8N 5+ unit. Two units related by an inversion centre interact through a pair of N—H...N hydrogen bonds, forming planar (CF 3COO −...C 4H 8N 5+...C 4H 8N 5+·CF 3COO −) aggregates that are linked by a pair of N—H...O hydrogen bonds into chains running along the c axis. 相似文献
12.
In the title compound, C 15H 16NO +·C 24H 20B −, the pyridinium ring of the cation makes a dihedral angle of 4.3 (2)° with the benzene ring. Each is rotated in the same direction with respect to the central C—CH=CH—C linkage, by 10.0 (2) and 7.8 (2)°, respectively. The anions have a slightly distorted tetrahedral geometry. The most interesting feature of the structure is that the anions form a honeycomb‐like hexagonal structure down the b axis through C—H...π interactions. The hexagon is constructed from six BPh 4− anions. The cations interact in a head‐to‐tail fashion along [010], forming chains, and pack antiparallel inside the above honeycomb‐like structure through C—H...π interactions. 相似文献
13.
The title compound, 3‐[(4‐amino‐2‐methylpyrimidin‐5‐yl)methyl]‐5‐(2‐hydroxyethyl)‐4‐methylthiazolium tetraphenylborate monohydrate, C 12H 17N 4OS +·C 24H 20B −·H 2O, is a salt in which the thiamine cations are linked by hydrogen bonds into a two‐dimensional network having (4,4)‐topology. The stacked sheets form channels, which are occupied by the anions; the cations and anions are linked by C—H⋯π(arene) hydrogen bonds. 相似文献
14.
Two 1:1 proton‐transfer complexes of sulfobenzoic acids with aromatic amines, namely 4‐[2‐(4‐pyridyl)ethenyl]pyridinium 2‐carboxybenzenesulfonate, C 12H 11N 2+·C 7H 5O 5S −, (I), and 1,10‐phenanthrolin‐1‐ium 4‐carboxybenzenesulfonate dihydrate, C 12H 9N 2+·C 7H 5O 5S −·2H 2O, (II), have very different hydrogen‐bonding patterns compared with reported organic sulfobenzoic acid complexes. In (I), two cations and two anions form a four‐molecule loop, in which π–π interactions occur. In (II), the anions and water molecules form a three‐dimensional hydrogen‐bonding network, while the cations only act as pendant components. The water molecules play a central role in the formation of the abundant hydrogen‐bonding architecture in (II). The relative poorness and richness of hydrogen bonds in (I) and (II), respectively, give rise to novel hydrogen‐bonding patterns. 相似文献
15.
In the title compound, C 6H 10N 3+·HSO 4−, the asymmetric unit consists of a hydrogen sulfate anion and a 2‐amino‐4,6‐dimethylpyrimidinium cation. The hydrogen sulfate anions self‐assemble through O—H⋯O hydrogen bonds, forming supramolecular chains along the b axis, while the organic cations form base pairs via N—H⋯N hydrogen bonds. The aminopyrimidinium cations join to the sulfate anions via a pair of hydrogen bonds donated from the pyrimidinium protonation site and from the exo amine group cis to the protonated site. 相似文献
16.
Pipes are the primary structural elements used for transporting fluid in various industries. The most common damage mechanism is corrosion, which occurs in pipes surface of turbine. The corrosive compounds for pipes are inorganic ion (Na +, Cl ?, NH 4+, NO 3?, etc.) and grinding oil. For rapid and quantitative detection of inorganic ions on site, more reliable and reproducible analytical methods are demanded. A highly efficient solid–liquid sampling collection system is introduced in this work. Papering on the sample surface, inorganic cations and anions were simultaneously collected and analyzed by capillary electrophoresis with indirect ultraviolet detection. As a result, five cations (Na +, K +, NH 4+, Ca 2+, Mg 2+) and three anions (Cl ?, NO 3?, SO 42?) were completely separated. The efficiency of the sampling and ability of capillary electrophoresis analysis were presented by the determination of trace‐level (mg/m 2) contaminants. The recoveries of cations and anions on the paper from metal surface were between 86.6 and 107.2%, and the relative standard deviations were less than 12.85%. 相似文献
17.
The crystal structure of the title compound, K +·C 6H 4NO 6S −, is built up from p‐nitrophenyl sulfate anions and potassium cations. Adjacent anions form dimers, which are linked together in a three‐dimensional network via short C—H⋯O contacts. The coordination sphere of the K + ions may be described as a distorted square antiprism. The crystal structure is further stabilized by π–π stacking interactions between the aryl rings. 相似文献
18.
The title salt, C 13H 12N 3+·H 2PO 4−, contains a nonplanar 2‐(2‐aminophenyl)‐1 H‐benzimidazol‐3‐ium cation and two different dihydrogen phosphate anions, both situated on twofold rotation axes in the space group C2. The anions are linked by O—H...O hydrogen bonds into chains of R22(8) rings. The anion chains are linked by the cations, via hydrogen‐bonding complementarities and electrostatic interactions, giving rise to a sheet structure with alternating rows of organic cations and inorganic anions. Comparison of this structure with that of the pure amine reveals that the two compounds generate characteristically different sheet structures. The anion–anion chain serves as a template for the assembly of the cations, suggesting a possible application in the design of solid‐state materials. 相似文献
19.
Ropinirole hydrochloride, or diethyl[2‐(2‐oxo‐2,3‐dihydro‐1 H‐indol‐4‐yl)ethyl]ammonium chloride, C 16H 25N 2O +·Cl −, belongs to a class of new non‐ergoline dopamine agonists which bind specifically to D2‐like receptors with a selectivity similar to that of dopamine (D3 > D2 > D4). The N atom in the ethylamine side chain is protonated and there is a hydrogen bond between it and the Cl − ion. In the crystal structure, two cations and two anions form inversion‐related cyclic dimers via N—H⋯Cl hydrogen bonds. 相似文献
20.
To enable a comparison between a C—H… X hydrogen bond and a halogen bond, the structures of two fluorous‐substituted pyridinium iodide salts have been determined. 4‐[(2,2‐Difluoroethoxy)methyl]pyridinium iodide, C 8H 10F 2NO +·I −, (1), has a –CH 2OCH 2CF 2H substituent at the para position of the pyridinium ring and 4‐[(3‐chloro‐2,2,3,3‐tetrafluoropropoxy)methyl]pyridinium iodide, C 9H 9ClF 4NO +·I −, (2), has a –CH 2OCH 2CF 2CF 2Cl substituent at the para position of the pyridinium ring. In salt (1), the iodide anion is involved in one N—H…I and three C—H…I hydrogen bonds, which, together with C—H…F hydrogen bonds, link the cations and anions into a three‐dimensional network. For salt (2), the iodide anion is involved in one N—H…I hydrogen bond, two C—H…I hydrogen bonds and one C—Cl…I halogen bond; additional C—H…F and C—F…F interactions link the cations and anions into a three‐dimensional arrangement. 相似文献
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