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PubMed2003

Trace metal behaviour in the Conwy estuary, North Wales.

The distribution of trace metals Zn, Ni, Mn, Fe, Cu, Pb, Cd and Cr between suspended particulate matter (SPM) and water in the Conwy estuary, North Wales, has been studied in three surveys in 1998. Dissolved Cu and Mn showed some monthly variations. Most of the dissolved trace metals displayed a negative association with salinity, indicating rivers as a major source of inputs for them. Particulate Zn, Mn and Fe showed a decreasing concentration seaward, whilst the levels of Ni, Cu, Cr and Pb increased with salinity. SPM concentration was the most important variable significantly related to trace metal concentrations in SPM, with an inverse relationship between the two parameters. This was explained by the relative enrichment of trace metals in fine particles at low SPM concentrations and relative depletion of trace metals in coarse particles at high SPM concentrations. Particulate Zn, Mn and Pb were dominated by the fraction available to acetic acid (non-detrital), whilst particulate Ni, Fe and Cr were dominated by the fraction available to nitric acid (detrital). The partition coefficient of trace metals between SPM and water declined with increasing SPM concentration, consistent with the so-called "particle concentration effect". Such a phenomenon may be explained by the presence of fine particles (including colloids) enriched with trace metals at low SPM concentrations, and the salinity-induced desorption.

Adsorption↗

PubMed2004

DNAPL remediation with in situ chemical oxidation using potassium permanganate. Part I. Mineralogy of Mn oxide and its dissolution in organic acids.

Previous studies on in situ chemical oxidation of trichloroethylene (TCE) with potassium permanganate indicated that the solid reaction product, Mn oxide, could reduce the permeability of the porous medium and impact the success of dense non-aqueous phase liquid (DNAPL) removal. In order to address the issue of permeability reduction caused by precipitation, this study investigated the mineralogy of Mn oxides and the possibilities of removing the solid precipitates by dissolution. The solid reaction product from the oxidation of TCE by permanganate is semi-amorphous potassium-rich birnessite, which has a layered mineral structure with an interlayer spacing of 7.3 A. The chemical formula is K(0.854)Mn(1.786)O(4).1.55H(2)O. It has a relatively small specific surface area at 23.6+/-0.82 m(2)/g. Its point of zero charge (pzc) was measured as 3.7+/-0.4. This birnessite is a relatively active species and could participate in various reactions with existing organic and inorganic matter. The dissolution kinetics of Mn oxide was evaluated in batch experiments using solutions of citric acid, oxalic acid, and ethylenediaminetetraacetic acid (EDTA). Initial dissolution rates were determined to be 0.126 mM/m(2)/h for citric acid, 1.35 mM/m(2)/h for oxalic acid, and 5.176 mM/m(2)/h for EDTA. These rates compare with 0.0025 mM/m(2)/h for nitric acid at pH=2. Organic acids dissolve Mn oxide quickly. Reaction rates increase with acid concentration, as tested with citric acid. The dissolution mechanism likely involves proton and ligand-promoted dissolution and reductive dissolution. Citric and oxalic acid can induce ligand-promoted dissolution, while EDTA can induce ligand-promoted and reductive dissolutions. At low pH, proton-promoted dissolution seems to occur with all the acids tested, but this process is not dominant. Reductive dissolution appears to be the most effective process in dissolving the solid, followed by ligand-promoted dissolution. These experiments indicate the significant potential in using these organic acids to remove precipitates formed during the oxidation reaction.

Chemical Precipitation↗

PubMed1997

Bioactive lipids in excitatory neurotransmission and neuronal plasticity.

Long-term potentiation (LTP), a model of activity-dependent synaptic plasticity and of certain forms of memory, comprises the persistent enhancement of excitatory neurotransmission that results from high-frequency activation. A presynaptic component of LTP is thought to be modulated by a retrograde messenger generated by the postsynaptic neuron. Arachidonic acid, nitric oxide, carbon monoxide and PAF have each been proposed as retrograde messengers in LTP, but arachidonic acid, unlike PAF, requires NMDA receptor activation. A PAF antagonist (BN 52021) that provides neuroprotection in ischemia-reperfusion displaces [3H] PAF bound to presynaptic membranes, blocks PAF-induced glutamate exocytosis and inhibits LTP. An antagonist selective for the intracellular PAF binding site (BN 50730) did not affect LTP, nor did BN 52021 modify NMDA currents. LTP was induced with weak synaptic stimulation coupled with postsynaptically administered enzyme resistant mcPAF. Theta-burst stimulation (10 min) after bath applications of mcPAF (1 microM) induced APV-independent LTP that was blocked by 5 microM BN 52021. When this antagonist was infused into the hippocampus before or immediately after training, it impaired memory of inhibitory avoidance training in the rat. Memory was not altered if the antagonist is infused 30 or 60 min after training. Moreover, mcPAF enhances memory on retention test performance of step-down inhibitory avoidance habituation and learning in rats. Also, memory was studied using a caudate nucleus-dependent cued water maze task. Rats received an 8 trial (30 s intertrial interval) training session in which a visible cued escape platform was located in a different quadrant of the maze of each trial. Following trial 8, the rats received a unilateral post-training intra-caudate injection of mcPAF (1 microgram/0.5 microliter), BN 52021 (0.5 microgram/0.5 microliter) or vehicle. On a retention test session 24 h later, latency to mount the escape platform was used as a measure of memory. The retention test escape latencies of rats given mcPAF were significantly lower than those of the vehicle-injected controls, indicating a memory enhancing effect of mcPAF. Injection of mcPAF did not affect retention when administered 2 h post-training, indicating a time-dependent effect of mcPAF on memory. The latencies for animals injected with BN 52021 were significantly higher than those of the controls, indicating that antagonism of endogenous PAF impairs memory. The findings show that PAF plays a role in memory formation in a caudate-mediated cued discrimination task. Administration of BN 52021 2 h post-training had no affect on retention, indicating a time-dependent effect of endogenous PAF on memory formation. PAF, the most potent bioactive lipid known, modulates excitatory synaptic transmission, neuronal plasticity and memory. When PAF production is overstimulated as in seizures or ischemia, it becomes neurotoxic.

Animals↗

PubMed1997

Supported liquid membrane enrichment combined with atomic absorption spectrometry for the determination of lead in urine.

Supported liquid membrane (SLM) methodology was used for sample clean-up and enrichment of lead in urine prior to determination by AAS. Lead ions at pH 3 were extracted across a membrane solution containing 40% m/m di-2-ethylhexylphosphoric acid dissolved in kerosene and back-extracted into an acceptor solution of 1 mol l-1 nitric acid. The mechanism of mass transfer is a proton gradient across the membrane. The concentration range investigated was between 5 and 80 ng ml-1 and the extraction time was varied between 0.5 and 4 h, leading to enrichment factors of up to 200. The extraction efficiency was about 95%. The detection limit, expressed as 3 sigma of five replicate determinations, using a 45 min enrichment of a urine sample low in lead, was 0.1 and 6.0 micrograms l-1 for ETAAS, and FAAS respectively. The results obtained by the developed method agreed with those obtained by direct ICP-MS determinations for reference urine samples and samples from occupationally lead-exposed workers. The linear correlation coefficient was 0.97, the slope of the regression line was 1.06 and the intercept was -0.37 microgram l-1. The 95% confidence intervals for the slope and the intercept were 0.95 to 1.18 and -3.9 to 3.1, respectively. The results at the 95% confidence level for reference urine material were of 91 +/- 1.5 and 92 +/- 2.0 micrograms l-1 for ICP-MS and SLM-AAS, respectively, which agreed well with the recommended value of 90 micrograms l-1 (range 83-97 micrograms l-1).

Lead↗

PubMed2002

An investigation of the chemical stability of arsenosugars in simulated gastric juice and acidic environments using IC-ICP-MS and IC-ESI-MS/MS.

A more quantitative extraction of arsenic-containing compounds from seafood matrices is essential in developing better dietary exposure estimates. More quantitative extraction often implies a more chemically aggressive set of extraction conditions. However, these conditions may result in undesirable chemical changes in the native arsenicals which may further complicate the toxicological risk assessment. This balance between quantitative extraction and species-specific integrity may be best addressed by using simulated gastric juice as an extraction solvent to mimic 'bioavailability'. This, conceptually, should extract the bioavailable fraction and induce any chemical changes that would occur because of ingestion. The most chemically labile species associated with seafood are thought to be the arsenosugars and for this reason their chemical stability is investigated in this study. Four arsenosugars (3-[5'-deoxy-5'-(dimethylarsinoyl)-beta-ribofuranosyloxy]-2-hydroxypropylene glycol, As(328); 3-[5'-deoxy-5'-(dimethylarsinoyl)-beta-ribofuranosyloxy]-2-hydroxypropanesulfonic acid, As(392); 3-[5'-deoxy-5'-(dimethylarsinoyl)-beta-ribofuranosyloxyl-2-hydroxypropyl hydrogen sulfate, As(408); and 3-[5'-deoxy-5'-(dimethylarsinoyl)-beta-ribofuranosyloxy]-2-hydroxypropyl-2,3-hydroxypropyl phosphate, As(482)) were isolated from seaweed extracts and subjected to simulated gastric juice and acidic conditions which mimic the stomach's pH of 1.1. Three acid solutions were used to test the chemical stability of the arsenosugars: simulated gastric juice, 78 mM nitric acid and 78 mM hydrochloric acid. The composition of the solutions was monitored over time (up to 48 h) using IC-ICP-MS for detection. The arsenosugars were found to degrade at the rate of 1.4% per h at 38 degrees C and 12.2% per h at 60 degrees C. The plots of percent conversion versus time were found to be independent of the starting arsenosugar and all had r2 values of greater than 0.97. A single common degradation product was observed in all the stability studies. A mass balance between the starting arsenosugar (As(392), As(408) and As(482)) and the degradation product was conducted with each set of experiments. This mass balance indicated that the degradation process did not produce any unchromatographable species. This degradation product was tentatively identified as As(254) as determined by ESI-MS/MS spectral data. An acid hydrolysis mechanism was proposed for the formation of As(254) from each of the native arsenosugars by hydrolysis at the C-1 carbon on the ribose ring.

Animals↗

PubMedDate not supplied

Determination of traces of iron in indium phosphide by electrothermal atomic absorption spectrometry combined with solvent extraction.

An electrothermal atomic absorption (ETAAS) method for the determination of traces of iron (0.1-1.0 microgram g-1) in Fe-doped indium phosphide (InP) has been developed. In order to overcome the indium matrix-effect and to achieve a useful detection limit, a preliminary solvent-extraction of Fe(III) with acetylacetone (HAA) is necessary. After sample dissolution with hydrochloric acid (1 + 1) the digest is evaporated to dryness, Fe(II) is oxidized to Fe(III) with nitric acid, the residue is dissolved in 0.01 mol L-1 HCl and the iron is extracted at pH 2.0 with 0.5 mol L-1 HAA in toluene. The organic phase is injected into the graphite furnace and the iron is directly evaluated by external organic standard calibration. The limit of detection (3SB) resulting from further in-situ preconcentration is 0.03 microgram g-1. When the method was applied to the analysis of real samples containing 0.2-0.7 microgram g-1 Fe, the RSD was in the range 8-21%. Results were compared with those independently obtained on the decomposed sample solution with inductively coupled atomic emission spectrometry (ICP-AES). The detection limit of the ICP-AES method, that needs matrix-matched standards, is 0.20 microgram g-1.

Environmental Monitoring↗

PubMed2004

Simultaneous determination of twelve inorganic and organic arsenic compounds by liquid chromatography-ultraviolet irradiation-hydride generation atomic fluorescence spectrometry.

A coupling between column liquid chromatography (LC) and atomic fluorescence spectrometry was developed for arsenic speciation. After separation, the compounds are oxidised on-line by UV irradiation, volatilised by hydride-generation and carried to the detector by a stream of argon. A combination of anion-exchange and hydrophobic interactions in a single column (Dionex AS7) was found suitable for the simultaneous separation of organic and inorganic species. Twelve compounds (arsenite, arsenate, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine, arsenocholine, trimethylarsine oxide, tetramethylarsonium ion and four arsenosugars) were separated using an acetate buffer and a nitric acid solution as mobile phases. Limits of detection are 4-22 pg. The technique was applied to three marine samples. Arsenobetaine was detected as the main species in all samples, with concentrations varying from 59 to 1947 ng(As) g(-1) of fresh mass.

Animals↗

PubMed1989

Assay of 1-hydroxy-3-aminopropylidene-1,1-bisphosphonate and related bisphosphonates in human urine and plasma by high-performance ion chromatography.

A method is described for the analysis of 1-hydroxy-3-aminopropylidene-1, 1-bisphosphonate and related bisphosphonates in human urine and plasma. Samples are spiked with 1-hydroxy-5-aminopentylidene-1,1-bisphosphonate as an internal standard and calcium chloride is added to precipitate the bisphosphonates. Following centrifugation the precipitate is redissolved in acetic acid, and the bisphosphonates are separated by high-performance ion chromatography on a Dionex AS7 column using nitric acid as mobile phase. The bisphosphonates are oxidised to orthophosphate using post-column addition of ammonium persulphate and this is followed by post-column reaction with molybdenum-ascorbate to yield the phosphomolybdate chromophore which is detected at 820 nm. A detection limit of 10 ng/ml is possible.

Chromatography, High Pressure Liquid↗

PubMed1990

Complete analysis of the trace elements of the kidney.

The distribution of trace elements in kidney cortex and medulla and in their subcellular fractions was studied by inductively coupled plasma mass spectrometry (ICP-MS). This technology allows the analysis of almost all the elements of the periodic table, along with their isotopes, in the same experiment. Acid digestion of the tissue (samples) was required before ICP-MS elemental analysis. Mineralization in 8 N nitric acid for 2 min in a Parr microwave acid digestion bomb, inside a regular microwave oven working at medium power, gave good sensitivity and reproducible results. Trace element determinations could be precisely performed, despite the presence of a considerable amount of organic matter. Cortex/plasma and medulla/plasma inorganic ratios were taken as indicators of the inorganic bioaccumulation. The highest enrichment factors of elements found in the cortex were Mn greater than Co greater than Tl greater than Zn greater than Rb greater than Mo greater than Cu and the highest element enrichments of the medulla were Tl greater than Mn greater than Co greater than Rb greater than Zn greater than Bi greater than Mo greater than Ni greater than Cu. Subcellular fragmentation of the kidney cortex and medulla indicated that the majority of the trace elements was located in the cytosolic fraction. The membrane fraction of the medulla contained significant amounts of Hg and Al: 120.7 and 32.0 mg/g protein, respectively. Cu and Zn were the most abundant trace elements found in the brush border membrane from the cortex: 120.7 and 68.2 mg/g protein, respectively. These quantities are largely in excess of what is bound, for example, to alkaline phosphatase.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMedDate not supplied

New developments in the understanding of cerebral vasoregulation and vasospasm: the endothelin-nitric oxide network.

Endothelins, which are powerful vasoconstrictors, and nitric oxide, which is a powerful vasodilator, together form a balanced system that regulates blood flow in the brain and in other organs. Ongoing research may yield new drugs that act on this system to prevent or reverse cerebral vasospasm in subarachnoid hemorrhage and other conditions. Many compounds are involved in cerebral vasoregulation under physiologic and pathologic conditions; of these, endothelins and nitric oxide have attracted considerable attention over the last several years. Endothelins and nitric oxide differ in chemical structure and pharmacological properties: endothelins are potent vasoconstrictor peptides consisting of 21 amino acids; nitric oxide is a free radical with a half-life of only a few seconds and exerts powerful vasodilatory effects. Both are produced by a number of cell types in the brain and interact at various levels to profoundly influence cerebral vessel function.

Animals↗

PubMed2003

The neurophysiology of the sexual cycle.

The cycle of sexual activity in men and women occurs in 4 phases--excitation, plateau, orgasm, resolution--which are guided by sexual desire. Male sexual activity is characterized by erection, seminal emission and ejaculation (orgasm), whereas female sexual activity is characterized by vaginal lubrication, erection of the clitoris and orgasm. These responses are under the control of numerous central and peripheral neural systems. The central supraspinal systems are mainly localized in the limbic system (olfactory nuclei, medial preoptic area, nucleus accumbens, amygdala, hippocampus etc.), in the hypothalamus and its nuclei (paraventricular and ventromedial nuclei). Neural information travels through the brain stem, the medulla oblongata, the spinal cord and the autonomous nervous system to the genital apparatus. While we have very detailed knowledge of the neural mechanism, which controls the function of the male and female genital organs, in particular those mediating erection, very little is known of the central mechanism involved. Nevertheless, several neurotransmitters and neuropeptides, such as dopamine, glutamic acid, nitric oxide, oxytocin, ACTH-MSH peptides, are known to facilitate sexual function, while serotonin, gamma-aminobutyric acid (GABA) and opioid peptides reduce it. At the level of the paraventricular nucleus a group of oxytocinergic neurons projecting to extra-hypothalamic brain areas, including the spinal cord, have been identified, which facilitate erectile function and copulation when activated and reduce both when inhibited. Although the majority of results, which have clarified the mechanisms involved, have been performed in males, it is believed that similar mechanisms are also operative in females.

Central Nervous System↗

PubMed1991

Determination of free nitrilotriacetic acid in environmental water samples by ion chromatography with potentiometric and amperometric detection with a copper electrode.

An ion-chromatographic method is described for the analysis of free nitrilotriacetic acid in water samples. Separations are achieved on a polymer-based anion-exchange column with 6 mM nitric acid as eluent. Both potentiometric and amperometric detection have been applied using metallic copper as the indicator electrode. Detection limits are at about 500 ng injected in the potentiometric mode and 100 ng in the amperometric mode. On-line sample preconcentration is possible for volumes up to 2 ml of river water samples. The response of the detector to other aminopolycarboxylic and aminopolyphosphonic acids has been investigated.

Chromatography, Ion Exchange↗

PubMed1998

Design of isoform-selective inhibitors of nitric oxide synthase.

Nitric oxide synthase, the mammalian enzyme catalyzing the oxidation of L-arginine to L-citrulline and nitric oxide, is present in three isoforms that have distinct physiological roles. Overstimulation or overexpression of individual nitric oxide synthase isoforms plays a role in a wide range of disorders including septic shock, arthritis, diabetes, ischemia-reperfusion injury, pain and various neurodegenerative diseases. Animal studies and early clinical trials suggest that nitric oxide synthase inhibitors could be therapeutic in many of these disorders, but preservation of physiologically important nitric oxide synthase functions might require use of isoform-selective inhibitors. Within the past few years both amino acid and nonamino acid nitric oxide synthase inhibitors with pharmacologically useful isoform selectivity have been reported. Selectivity has been achieved on the basis of initial binding affinity and, for mechanism-based inactivators, on the basis of isoform-dependent catalytic activation; particularly interesting are N5-(1-imino-3-butenyl)-L-ornithine, ARL 17477, 1400W and S-(2-aminoethyl)isothiourea.

Animals↗

PubMed1991

Vascular biology of coronary bypass grafts.

Clinical studies on the natural history of coronary bypass grafts strongly suggest that biologic properties of the vessels used importantly affect their function and patency. The endothelium is a source of substances regulating vascular tone, platelet function, and vascular growth; it produces nitric acid from L-arginine, which is a potent vasodilator and inhibitor of platelet function and has antiproliferative properties. Nitric oxide and prostacyclin, which have a similar profile of action, are released in greater amounts in arterial than venous coronary bypass vessels. Vascular smooth muscle cells are primary regulators of local blood flow and contribute to proliferative responses. The right gastroepiploic artery exhibits more pronounced contractions than the mammary artery but has a similar sensitivity to vasoconstrictors. Proliferative responses in coronary bypass vessels appear to be induced by changes in transmural pressure (particularly in veins), endothelial damage, and in turn, local release of platelet-derived growth factors, low-density lipoproteins, and intrinsic characteristics of the blood vessels. Thus, biologic properties of the endothelium and vascular smooth muscle significantly contribute to the function and patency of coronary bypass grafts. While the mammary artery has near-ideal characteristics, the right gastroepiploic artery exhibits marked contractile responses and the saphenous vein has unsatisfactory antithrombotic properties and more pronounced proliferative responses.

Animals↗

PubMed2006

Distribution of uranium contamination in weathered fractured saprolite/shale and ground water.

The objective of this study was to determine how structure, stratigraphy, and weathering influence fate and transport of contaminants (particularly U) in the ground water and geologic material at the Department of Energy (DOE) Environmental Remediation Sciences Department (ERSD) Field Research Center (FRC). Several cores were collected near four former unlined adjoining waste disposal ponds. The cores were collected, described, analyzed for U, and compared with ground water geochemistry from surrounding multilevel wells. At some locations, acidic U-contaminated ground water was found to preferentially flow in small remnant fractures weathering the surrounding shale (nitric acid extractable U [U(NA)] usually < 50 mg kg(-1)) into thin (<25 cm) Fe oxide-rich clayey seams that retain U (U(NA) 239 to 375 mg kg(-1)). However, greatest contaminant transport occurs in a 2 to 3 m thick more permeable stratigraphic transition zone located between two less permeable, and generally less contaminated zones consisting of (i) overlying unconsolidated saprolite (U(NA) < 0.01 to 200 mg kg(-1)) and (ii) underlying less-weathered bedrock (U(NA) generally < 0.01 to 7 mg kg(-1)). In this transition zone, acidic (pH < 4) U-enriched ground water (U of 38 mg L(-1)) has weathered away calcite veins resulting in greater porosity, higher hydraulic conductivity, and higher U contamination (U(NA) 106 to 745 mg kg(-1)) of the weathered interbedded shale and sandstone. These characteristics of the transition zone produce an interval with a high flux of contaminants that could be targeted for remediation.

Environmental Monitoring↗

PubMed2001

Morphological support for paracrine inhibition of gastric acid secretion by nitric oxide in humans.

BACKGROUND: Functional studies have shown that nitric oxide (NO) inhibits gastric acid secretion in a variety of species, including man. We have performed a morphological study with the intention of localizing the endothelial NO synthase (eNOS) in the human gastric mucosa. METHODS: Fifteen healthy subjects voluntarily participated in the study, and mucosal biopsies were obtained from the cardia, corpus and antrum. The presence and localization of eNOS were studied using immunohistochemical techniques. RESULTS: eNOS-immunoreactivity (eNOS-IR) is found in surface mucous cells of cardia, corpus and antrum. Unique to the oxyntic mucosa is the presence of eNOS-IR in 'endocrine-like' cells, found in close contact with parietal cells. CONCLUSIONS: eNOS-IR cells in close apposition to parietal cells provide morphological support for paracrine inhibition of gastric acid secretion by NO.

Adult↗

PubMed1991

Release of nitrogen oxides from cultured bovine aortic endothelial cells is not impaired by calcium channel antagonists.

BACKGROUND: The endothelium-derived relaxing factor has been shown to be nitric oxide or a related nitroso compound, synthesized by the enzyme nitric oxide synthetase, which oxidizes the guanidono nitrogens of arginine. This enzyme is activated by increases in cytosolic calcium. The effect of the clinically used calcium channel antagonists on this process is controversial. The present study was performed to determine whether calcium channel blockade with these pharmacologic agents would alter the activity of nitric acid synthetase in intact endothelial cells. METHODS AND RESULTS: A specific and sensitive chemiluminescence assay was used to measure the release of nitrogen oxides (nitric oxide and one-electron oxidation products of nitric oxide) from bovine aortic endothelial cells grown in culture. Under basal conditions, the release of nitrogen oxides was about 0.2 nmol/100 micrograms protein/hr. Bradykinin doubled this response. Removal of extracellular calcium abolished basal and bradykinin-stimulated release of nitrogen oxides. Neither diltiazem, verapamil, nor nifedipine in concentrations that are encountered clinically altered the release of nitrogen oxides. CONCLUSIONS: These experiments show that although the production of nitrogen oxides is dependent on extracellular calcium, the clinically used calcium channel antagonists do not inhibit the release of the endothelium-derived relaxing factor.

Amino Acid Oxidoreductases↗

PubMed2001

Extraction of bismuth(III) with 2-bromoalkanoic acid in nondonating solvent from highly acidic aqueous solution.

The extraction behaviors of bismuth(III) with carboxylic acid (HL), which have not yet been clearly elucidated, because of the precipitation of hydroxide, were studied using the 2-bromoalkanoic acid in benzene and in hexane systems under aqueous conditions of high acidity at I = 1.0 M ((H,Li)NO3). The extraction equilibria were analyzed based on the-initial concentration of nitric acid and the concentration of bismuth(III) extracted in the organic phase. The extracted species and the logarithmic values of the extraction constant (log Kex) were found to be a single species of BiL3(HL)3 for the systems of 2-bromooctanoic acid/benzene (log Kex = -1.66) and 2-bromohexadecanoic acid/benzene (-1.58), and to be two species of BiL3(HL)4 (-1.01) and Bi3L9HL (-1.62) for the system of 2-bromooctanoic acid/hexane, where the monomer was dominant at a higher reagent concentration.

Journal Article↗