Lanthanum Carbonate Research Articles

Enhanced ICP-MS detection of 24 elemental impurities in complex, high matrix mineral, medicinal lanthanum carbonates according to ICH Q2 (R2).

Validation of the specificity of ICP-MS methods by ICH Q2 (R2) through spiking experiments cannot characterize the multi-atomic interference of complex high matrix samples, possibly affecting the accuracy of the method and reliability of results. In this study, we highlight this issue by investigating the elemental impurities in lanthanum carbonate raw materials and use isotope ratio analysis to overcome this limitation and establishing an accurate ICP-MS method for 24 elemental impurities (listed in ICH Q3D). An Agilent 7900 ICP-MS was used with an automatic sampler for sample determination in the He mode. The isotope ratio of elemental impurities in the spiked samples was analyzed to characterize polyatomic interference and select the exclusive mass number of elemental impurities. While the recovery rate of most elemental impurities met the requirements, that of selenium (default measurement mass number 78Se) exceeded the standard in the matric sample. The isotope ratio of Se (78Se/82Se) was much higher than the theoretical value, indicating that the response intensity of m/z 78 was formed by the combination of 78Se and other mass-to-charge ratios, such as LaOH2+ formed by the large amount of La in the matrix. Therefore, 82 was chosen as the mass number for Se. The validation results indicate that the method has strong specificity, high accuracy, and is simple and facile. This study provides technical support for the control of elemental impurities in lanthanum carbonates and isotope ratios can be used as a supplementary means of spiked recovery rates.

Modular hydrogel selectively adsorbs phosphates and hexavalent chromium while enabling phosphate recovery

Electroplating wastewater containing high concentrations of phosphates and hexavalent chromium Cr(VI) poses serious environmental pollution. Moreover, phosphorus, as a non-renewable resource, necessitates its recovery to meet sustainable development goals. To address this issue, this study used sodium alginate as the scaffold module, synthesized lanthanum carbonate in situ within a chitosan module to serve as the phosphate adsorption module, and employed polyethyleneimine (PEI) modules to enhance the adsorption capacity for Cr(VI), successfully fabricating a modular hydrogel (LC-CSP). LC-CSP exhibits a complex porous structure and surface morphology, forming an ultra-low-density fiber network with good strength and elasticity, ensuring uniform distribution and exposure of active sites. Under optimal conditions for single-component adsorption, LC-CSP achieved adsorption capacities of 232.02 mg/g for phosphates and 474.61 mg/g for Cr(VI). Additionally, LC-CSP demonstrated excellent reusability, retaining over 83 % of its performance after five cycles. In simulated electroplating wastewater experiments with various interfering substances, LC-CSP maintained high removal efficiencies (>90.72 %) for phosphates and Cr(VI). Post-experiment, enriched water after phosphate desorption was further treated to recover phosphorus resources in complex water environments. Multiple characterization techniques elucidated the adsorption mechanisms of LC-CSP: phosphate adsorption primarily involved ligand exchange, electrostatic interactions, and hydrogen bonding, while Cr(VI) adsorption included electrostatic interactions, hydrogen bonding, and reduction reactions. Finally, fixed-bed simulated wastewater adsorption experiments validated the technical potential of LC-CSP for practical electroplating wastewater management.

In Vitro Study on Combined Effect of Drugs for Hyperphosphatemia on Phosphorus Adsorption Capacity.

Phosphorus binders are often used in combination to produce synergistic effects. However, the synergistic effect may be affected by the change in pH or concomitant drugs. Nonetheless, the data on the adsorption capacities of these binders when used in combination with other binders are limited. In this study, we evaluated the adsorption capacity of phosphorus binders when used in combination. Precipitated calcium carbonate (CC), ferric citrate hydrate (FC), lanthanum carbonate hydrate (LC), and sucroferric oxyhydroxide (SO) were used as phosphorus binders. SO showed high adsorption capacity in the 1st and 2nd fluid, and the adsorption capacity of SO in combination with other binders was stable. In contrast, the adsorption capacities of CC + FC and FC + LC decreased in the 1st and 2nd fluid compared with that when used alone because of the release of citrate ions that chelate calcium or lanthanum ions. These results suggest that SO is less affected by interactions with other phosphorus binders and changes in pH and may be suitable for patients receiving concomitant drugs.

Lanthanum chloride exerts therapeutic potential for chronic kidney disease by suppressing nanohydroxyapatite-induced mitophagy and mitochondria-mediated apoptosis

ObjectiveTo investigate the protective effect of lanthanum chloride on kidney injury in chronic kidney disease and its mechanism. Methods1. Patients with CKD stage 2–5 were selected to analyze the effect of lanthanum-containing preparations on CKD. 2. Sixty healthy male Wistar rats were randomly divided into control group, model group, lanthanum chloride groups (0.03 ng/kg, 0.1 ng/kg, 0.3 ng/kg, q.3d., i.v.), and lanthanum carbonate group (0.3 g/kg, q.d., p.o.). The model group was given 2 % adenine suspension (200 mg/kg, q.d., p.o.) for the first two weeks, followed by adenine (200 mg/kg, b.i.d., p.o.) for 2 weeks, and all animals were sacrificed after eight weeks of administration. 3. The serum and kidneys of rats in each group were collected to detect the oxidative stress indicators and the expressions of LC3B-Ⅱ/Ⅰ, p62, Bcl-2, Bax, Caspase-3 and Cleaved Caspase-3. 4. Human renal tubular epithelial cells (HK-2 cells) were divided into control group, model group, lanthanum chloride group, pyrophosphate (PPI) group, chloroquine (CQ) group, rapamycin group, doxorubicin (DOX) group and N-acetyl-L-cysteine (NAC) group. The mitochondrial status, mitophagy and apoptosis levels were detected. Results1.Lanthanum-containing preparations can significantly reduce the biochemical indexes of kidney injury in patients with CKD. 2. In the model group, the glomerular and renal tubular edema, the mitochondria were short and round, and the expression of LC3B-Ⅱ/Ⅰ and Bax increased, while the expression of P62, Bcl-2 and Caspase-3 decreased, and there was a significant improvement in the administration group, especially the 0.1 ng/kg group and lanthanum carbonate group. 3. In the HK-2 cell model group, mitochondrial membrane potential decreased, morphology changed and the results were reversed by lanthanum chloride. ConclusionLanthanum chloride may alter the morphology of nano-hydroxyapatite, thereby inhibiting its induced mitophagy and mitochondria-mediated apoptosis, and ultimately improve CKD renal injury effectively.

Lanthanum deposition of the gastric mucosa in a dialysis patient.

A 49-year-old man presented for a screening esophagogastroduodenoscopy (EGD) as part of his registration for a donated kidney transplant. He had been on hemodialysis for 4 years for end-stage renal disease (ESRD) due to diabetic nephropathy. He was taking lanthanum carbonate (LaC) for hyperphosphatemia. A plain abdominal radiograph and CT showed the radiopaque appearance of LaC. EGD disclosed whitish spots resembling xanthomas in the stomach. Biopsies showed deposition of granular crystalline-like material and phagocytosis of these by multinucleated giant cells on HE staining. These histiocytes were positive for CD68. La deposition was suspected because of the long-term oral administration of LaC. LaC is commonly used to treat hyperphosphatemia in patients with ESRD. La deposition on the gastric mucosa presents with various endoscopic findings, including whitish spots, annular whitish mucosa, and diffuse whitish mucosa. The gastric endoscopic findings of La deposition reflect the infiltrated histiocytes and not the LC deposition itself. Our case highlights the importance of recognizing the rare but characteristic imaging findings of gastrointestinal La deposition in hemodialysis patients who are taking LaC.

Incorporation of electronically and ionically conductive additives in high-loading sulfur cathodes in lean-electrolyte lithium–sulfur cells

Low-cost, high-energy-density lithium–sulfur electrochemical batteries have emerged as a promising solution for next-generation energy-storage technologies. To facilitate the practical application of such batteries, it is necessary to address the remaining scientific and engineering challenges, especially those associated with the high-loading sulfur cathode in a lean-electrolyte cell. In this study, we investigate the electrochemical and overall performance of lithium–sulfur cells with a high-loading sulfur cathode. Notably, this cathode is fabricated using a novel hot-pressing method and incorporates electronically and ionically conductive additives, specifically lithium lanthanum titanate (LLTO) and carbon black, respectively. Material analysis reveals the uniform distribution of additives in the cathodes, with the ionically conductive LLTO effectively adsorbing and converting polysulfides and carbon black enhancing the cathode conductivity. Electrochemical analysis of the lean-electrolyte cells shows that the incorporation of LLTO improves cell performance, with enhanced discharge capacity of 715–836 mAh g−1 at C/5–C/10 rates and notable capacity retention after 100 cycles, compared with cathodes without additives or with carbon black. Further investigations demonstrate the superior performance of the cell incorporating LLTO in a LiNO3-free electrolyte, attributable to the promotion of ion transport and polysulfide adsorption by LLTO, resulting in high discharge capacities (846 mAh g−1 at C/10), efficiency (93–99 %), and stability. Overall, this study compares the effects of electronically and ionically conductive additives on cell performance and highlights the effectiveness of the ionically conductive LLTO. The incorporation of such additives offers innovative solutions to the key challenges for the development of high-performance energy-storage devices.

Direct Catalytic Conversion of Carbon Dioxide to Liquid Hydrocarbons over Cobalt Catalyst Supported on Lanthanum(III) Ion‐Doped Cerium(IV) Oxide

AbstractDirect CO2 conversion to liquid hydrocarbons (HCs) in a single process was achieved using cobalt (Co) catalysts supported on lanthanum ion (La3+)‐doped cerium oxide (CeO2) under a gas stream of H2/CO2/N2=3/1/1. The yield of liquid HCs was the highest for 30 mol% of La3+‐doped CeO2, which was because extrinsic oxygen vacancy formed by doping La3+ could act as an effective reaction site for reverse water gas shift reaction. However, the excess La3+ addition afforded surface covering lanthanum carbonates, resulting in depression of the catalytic performance. On the other hand, bare CeO2 lead to an increase in the selectivity of undesirable methane, which arose from reduction of CO2 to CO proceeding by intrinsic oxygen vacancy generated by only Ce3+, and weaker CO2 capture ability of intrinsic oxygen vacancy than extrinsic one, resulting in the proceeding of Sabatier reaction on Co catalyst. The rational design of reaction sites presented in this study will contribute to sustainability.

Preparation of a novel LC@MWCNTs membrane and its application for enhanced phosphate removal and fouling control

To control the eutrophication originating from phosphate discharge, a novel adsorptive membrane was prepared by vacuum filtrating lanthanum carbonate modified multi-walled carbon nanotubes (LC@MWCNTs) on the UF membrane. The LC@MWCNTs were firstly made using an in-situ method by adding MWCNTs to LaCl3·7H2O solution and forming lanthanum carbonate under alkaline conditions. The adsorption experiments exhibited that the maximum adsorption capacity of LC@MWCNTs was 77.58 mg P/g at pH 5. And the phosphate adsorption by LC@MWCNTs was not predominantly reliant on electrostatic interaction, but rather achieved through chemical interactions. Then, the prepared LC@MWCNTs membrane was systematically evaluated for its phosphate removal efficiency and anti-fouling performance during filtration. With the initial phosphate concentration of 1 mg P/L and membrane flux of 378 L·m−2 h−1, the phosphate removal by LC@MWCNTs membrane approached almost 100 %. Moreover, the LC@MWCNTs membrane exhibited higher permeability (281.6 L·m−2h−1bar−1) and effectiveness for humic acid (HA) removal (75 %), and LC@MWCNTs membrane mitigated the fouling caused by HA. XPS, FTIR and XRD elucidated that phosphate removal by LC@MWCNTs membrane primarily through the formation of La-O-P inner-sphere complexes via ligand exchange, resulting in the formation of adsorption product LaPO4·0.5H2O. Under strong alkaline conditions, the LC@MWCNTs membrane rapidly restored its phosphate removal performance (30 min) with no significant detachment of the LC@MWCNTs layer, indicating its good recovery and reusability performance. Additionally, the LC@MWCNTs membrane could continuously remove phosphate from actual water, confirming its potential for future practical applications.

Surface Reconstruction of La2CuO4 during the Electrochemical Reduction of Carbon Dioxide to Ethylene and Its Benefits for Enhanced Performance.

Electrochemical reduction (ECR) of CO2 to C2H4 has a potential key role in realizing the carbon neutral future, which ultimately relies on the availability of an efficient electrocatalyst that can exhibit a high Faradaic efficiency (FE) for C2H4 production and robust, long-term operational stability. Here, for the first time, we report that upon applying reductive potential and electrolyte to the benchmark La2CuO4 catalyst, surface reconstruction occurred, i.e., the appearance of a distinctive phase evolution process over time, which was successfully monitored using ex situ powder XRD and operando Mott-Schottky (M-S) measurements of La2CuO4 samples that were soaked into the electrolyte and subjected to CO2-ECR for different durations. At the end of such a reconstruction process, an outermost layer consisting of lanthanum carbonate, a thin outer layer made of an amorphous Cu+ material formed over the core bulk La2CuO4, as confirmed by various characterization techniques, which resulted in the redistribution of interfacial electrons and subsequent formation of electron-rich and electron-deficient interfaces. This contributed to the enhancement in FE for C2H4, reaching as much as 58.7%. Such surface reconstruction-induced electronic structure tuning gives new explanations for the superior catalytic performance of La2CuO4 perovskite and also provides a new pathway to advance CO2-ECR technology.

Long-term safety of lanthanum carbonate in the real word: a 19-year disproportionality analysis from the FDA Adverse Event Reporting System

Background Lanthanum carbonate is widely used to manage serum phosphate and calcium levels in end-stage kidney disease (ESKD) patients, yet comprehensive long-term safety data are lacking. This study leverages the FDA Adverse Event Reporting System (FAERS) to assess the extended safety profile of lanthanum carbonate. Research design and methods We analyzed FAERS data (2004-2022) to study the association between lanthanum carbonate and adverse events (AEs). Using MedDRA v25.0, we identified risk signals through System Organ Classes (SOCs) and Preferred Terms (PTs). Disproportionality analyses quantified lanthanum carbonate-associated AE signals. Results Among 3,284 reports, 2,466 were primary suspected AEs linked to lanthanum carbonate. Males reported AEs more frequently than females. Patients aged over 64 represented the majority. Median onset time for lanthanum carbonate-related AEs was 146 days. Gastrointestinal disorders were prevalent. We identified 16 new signals, including stress, abnormal hepatic function, cholelithiasis, bile duct stone, gastric cancer, and adenocarcinoma gastric. Stress was notable, particularly in male patients over 65 and those with lower weight. Conclusions This study affirms lanthanum carbonate’s long-term safety for reducing elevated blood phosphorus levels. While gastrointestinal disorders were common, attention must focus on emerging AEs, particularly stress, especially in elderly patients.

#1579 The effectiveness and safety of sucroferric oxyhydroxide in the treatment of hyperphosphatemia in dialysis patients: a systematic review

Abstract Background and Aims Hyperphosphatemia is an independent prognostic factor for mortality in dialysis patients. The most widely used phosphate binders are sevelamer and lanthanum carbonate. Poor compliance may be due to high pill burden and gastrointestinal adverse reactions. Some previous studies on sucroferric oxyhydroxide showed a potential reduction of phosphorus levels and pill burden. This study aims to determine the effectiveness and safety profile of sucroferric oxyhydroxide in the control of hyperphosphatemia in dialysis-dependent patients. Method A systematic search was conducted in the Cochrane Library, MEDLINE, TRIP Database, and ClinicalTrials.gov until Jan 8, 2024. All randomized controlled trials on the use of sucroferric oxyhydroxide for the treatment of hyperphosphatemia in adult dialysis patients were included. The comparator groups considered were sevelamer or lanthanum. The outcomes of interest were post-treatment serum phosphorus level, the change of serum phosphorus level from baseline, hemoglobin level, ferritin level, transferrin saturation level, adverse events, serious adverse events, and all-cause mortality. Two authors independently searched for articles, screened the articles for inclusion, and appraised the articles using the REVMAN risk of bias table. The GRADE was used to assess the certainty of evidence. In case of a disagreement, the two authors discussed until a consensus was reached. If a consensus was not reached, an independent third-party reviewer was consulted. Meta-analysis was conducted using Review Manager 5.4.1 software. Results We included 7 RCTs represented by 11 records and a total of 2031 adult dialysis patients with hyperphosphatemia. The usual dose of sucroferric oxyhydroxide is 750 mg-3000 mg/day. Sucroferric oxyhydroxide reduces serum phosphorus levels comparable to that of sevelamer (MD = −0.03 mmol/L, 95% CI −0.10 to 0.03, I2 49%) and of lanthanum (MD = −0.02 mmol/L, 95% CI −0.36 to 33, I2 0%). The decrease in serum phosphorus level from the baseline is also comparable with sevelamer (MD = −0.06 mmol/L, 95% CI −0.13 to 0.00, I2 59%). Sucroferric oxyhydroxide significantly reduces the daily number of tablet intake (MD = −7.09 tablets/day, 95% CI −10.45 to −3.73, p-value < 0.0001, I2 = 99%) compared to sevelamer. The use of sucroferric oxyhydroxide shows significantly higher hemoglobin level (MD = 1.15; 95% CI 0.92 to 1.39, p-value < 0.0001, I2 = 0%), higher transferrin saturation level (MD = 8.33; 95% CI 6.06 to 10.59, p-value < 0.0001, I2 = 0%) and higher ferritin level (MD = 64.16; 95% CI 31.64 to 96.68, p-value 0.0001) compared with the use of sevelamer. Pooled analysis on sucroferric oxyhydroxide showed no significant differences in adverse events (RR = 1.05, 95% CI 0.95 to 1.17, I2 = 47%); serious adverse events (RR = 1.11, 95% CI 0.84 to 1.47, I2 = 0%) and all-cause mortality (RR = 0.94; 95% CI 0.38 to 2.31, I2 = 0%) compared to sevelamer. The most common adverse events reported were nausea, diarrhea, abdominal discomfort, fecal discoloration, and hyperphosphatemia. Conclusion Sucroferric oxyhydroxide is comparable with sevelamer and lanthanum in decreasing serum phosphorus levels. It is also associated with higher hemoglobin, ferritin, and transferrin saturation levels compared with the sevelamer group. Since there are no significant differences in the risks of adverse events, serious adverse events, and all-cause mortality, the decrease in pill burden with sucroferric oxyhydroxide may help improve patient compliance.

#346 Oxylanthanum carbonate for hyperphosphatemia in ESKD: tolerability trial in progress

Abstract Background and Aims Despite current therapies, more than 43% of patients undergoing dialysis in the USA have hyperphosphatemia, defined as serum phosphate values >5.5 mg/dL and is commonly associated with an increased risk of death. Most currently available phosphate binders are known to cause gastrointestinal (GI) adverse events (AEs) that can negatively impact the patient experience. Common GI AEs include abdominal pain, nausea, and bloating. Phosphate binders are usually formulated as large tablets, and some must be chewed before ingestion. Commonly a high number of pills are needed per day to achieve goal serum phosphate levels. Oxylanthanum carbonate (OLC) is a new lanthanum-based nanotechnology product in development with a high in vitro binding capacity as compared to other phosphate binders. OLC is formulated as a small pill that is swallowed whole instead of being chewed before swallowing as is the case for lanthanum carbonate. The safety of OLC has been studied in >100 healthy subjects. The most common treatment-related AE (>5%) in an OLC bioequivalence (BE) study was nausea. This study aims to evaluate the tolerability of clinically effective (serum phosphate ≤5.5 mg/dL) doses of OLC in patients on hemodialysis. Method This open-label, single-arm, multicenter, multidose study will enroll up to 90 patients on hemodialysis who require phosphate binder therapy and have mean historical serum phosphate levels between ≥4.0 and ≤7.0 mg/dL for ≥8 weeks. The primary endpoint of the study is tolerability as assessed by the incidence of discontinuations due to treatment-related AEs. Additionally, the incidence of AEs related to OLC will be collected. Participants will undergo up to 3 weeks of phosphate binder washout until their serum phosphate levels reach >5.5 and ≤10.0 mg/dL (Fig. 1). During the 6-week Titration Period, all patients will receive 1500 mg/day OLC (500 mg TID with meals/snacks) for the initial 2 weeks, with subsequent titration every 2 weeks until achieving a target serum phosphate level (≤5.5 mg/dL) or to a maximum OLC dose of 3000 mg/day. After titration, patients will enter a 4-week Maintenance Period at the effective OLC dose. Results We intend to present results elucidating tolerability of clinically effective doses of OLC in patients on dialysis. Conclusion The tolerability of OLC at doses effective in achieving a serum phosphate ≤5.5 mg/dL in patients on hemodialysis will be evaluated in this study.

Enhancing Interaction between Lanthanum Manganese Cobalt Oxide and Carbon Black through Different Approaches for Primary Zn-Air Batteries.

Due to the need for decarbonization in energy generation, it is necessary to develop electrocatalysts for the oxygen reduction reaction (ORR), a key process in energy generation systems such as fuel cells and metal-air batteries. Perovskite-carbon material composites have emerged as active and stable electrocatalysts for the ORR, and the interaction between both components is a crucial aspect for electrocatalytic activity. This work explores different mixing methods for composite preparation, including mortar mixing, ball milling, and hydrothermal and thermal treatments. Hydrothermal treatment combined with ball milling resulted in the most favorable electrocatalytic performance, promoting intimate and extensive contact between the perovskite and carbon material and improving electrocatalytic activity. Employing X-ray photoelectron spectroscopy (XPS), an increase in the number of M-O-C species was observed, indicating enhanced interaction between the perovskite and the carbon material due to the adopted mixing methods. This finding was further corroborated by temperature-programmed reduction (TPR) and temperature-programmed desorption (TPD) techniques. Interestingly, the ball milling method results in similar performance to the hydrothermal method in the zinc-air battery and, thus, is preferable because of the ease and straightforward scalability of the preparation process.

Mechanistic study of highly effective phosphate removal from aqueous solutions over a new lanthanum carbonate fabricated carbon nanotube film

The effective purification of phosphate-containing wastewater is considered as increasingly important. In this study, a highly effective LC-CNT film was developed for efficient phosphate removal. Kinetic results showed that the adsorbent exhibited an improved mass transfer efficiency and a fast adsorption rate during adsorption (reaching 80% and 100% equilibrium adsorption capacity within 175 and 270 min, respectively). Kinetic model analysis suggested that the adsorption was a combined chemical physical process. Isotherm study revealed that the LC-CNT film showed a superior adsorption capacity (178.6 mg/g, estimated from the Langmuir model) with multiple adsorption mechanisms. pH study suggested that surface complexation and ligand exchange played important roles during adsorption, and the adsorbent worked well within the pH range of 3–7 with little La leakage. The ionic strength and competing anions showed little influence on the adsorbent effectiveness except for the carbonate and sulfate ions. The characterization and mechanism study revealed that the phosphate adsorption of the LC-CNT film was controlled by inner-sphere complexation, outer-sphere complexation and surface precipitation. The LC-CNT film also showed excellent regenerability and stability in cycling runs, further demonstrating its potential in industrial applications.

Selective phosphate removal by lanthanum carbonate @ anion exchange resin with fixed-bed column: RSM for process optimization and DFT for mechanistic study

Lanthanum carbonate @ anion exchange resin (LC@AER) has shown promise in adsorption processes due to its high maximum adsorption capacity and excellent stability in comparison with other lanthanum-based adsorbents. Nevertheless, there is a lack of significant investigation in evaluating the collective effect of the most influential parameters and determining the molecular complexes between the adsorbent and phosphate. This work aims to comprehensively evaluate and optimize the phosphate adsorption performance in fixed-bed columns and to determine the most favourable molecular configurations. Firstly, a response surface model (RSM) was developed to describe the phosphate adsorption performance in fixed-bed columns under the collective effect of selected independent variables, including influent pH, co-existing sulfate concentration, and empty bed contact time (EBCT). The RSM analysis reveals the significant effects of influent pH and co-existing sulfate concentration on phosphate adsorption. Moreover, the model achieves a correlation coefficient of >0.9, demonstrating its suitability for describing the experimental data. Secondly, various phosphate-lanthanum carbonate configurations were formulated, and the respective adsorption energies were compared using density functional theory (DFT) calculations. Subsequently, bidentate mononuclear complexes are determined as the most favourable configurations. The successful matching of the simulated peak locations with the experimental deconvoluted spectra further confirms the presence of such complexes in the system. Overall, this work provides an improved foundation and underlayer theory for potential future scale-up work on phosphate adsorption over LC@AER.

Safety and efficacy of a feed additive consisting of lanthanum carbonate octahydrate for dogs (Porus GmbH).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of lanthanum carbonate octahydrate as a zootechnical feed additive for dogs. The additive is already authorised for use in feed for cats. The FEEDAP Panel concluded that the additive lanthanum carbonate octahydrate is safe for adult dogs at the maximum recommended level of 7500 mg/kg complete feed. The additive is not irritant to skin or eyes, is not a skin sensitiser and exposure by inhalation is considered to be unlikely. The Panel also concluded that lanthanum carbonate octahydrate is efficacious in the reduction of phosphorus bioavailability in adult dogs at the minimum inclusion level of 1500 mg/kg complete feed.

Facile synthesis of lanthanum carbonate octahydrate and lanthanum oxide nanoparticles by sonochemical method: systematic characterizations

Abstract This study could present the size and morphology of two synthesized nanoparticles (NPs) by observing their smallest possible dimensions. Lanthanum carbonate nanoparticles were synthesized by sonochemical method through the interaction of lanthanum acetate hydrate and sodium carbonate in an aqueous medium with a probe sonicator. After rigorous washing followed by drying, the La2(CO3)3·8H2O(S1) NPs were calcined at a temperature of 600 °C to obtain lanthanum oxide nanoparticles (S2). Both NPs were characterised through various instrumental techniques. PXRD study showed orthorhombic with space group of Pccn (56) and hexagonal phases with space group of P 3 ‾ m 1 $P\overline{3}m1$ (164) for S1 and S2 respectively whose morphology and elemental analysis were studied through FESEM and EDX. High resolution TEM image of La2(CO3)3·8H2O and La2O3 showed spherical shapes of the nanoparticles. Further study of XPS and FTIR conveyed detailed information of both nanoparticles whose TGA-DSC showed three step decomposition curves. The size and morphology of the synthesized nanoparticles have been found to have a distinct morphology and are found comparatively smaller in size than those observed in the earlier reported works (Table 1 Table 1: Comparative study of synthesized lanthanum carbonate and lanthanum oxide NPs with various techniques applied by other researchers. Sl. no. Name of NPs Methods Conditions Size of NP Reference 1 La2(CO3)3·8H2O Sonochemical method Time: 25 min XRD: Pccn (56) a = 8.9840 Å b = 9.5800 Å c = 17.0000 Å This work Temperature: 301 K Size: 24.102 nm Starting materials:(a) La(CH3COO)2: 0.050 M(b) Na2CO3:0.050 M TEM: Size: 4–30 nm La2(CO3)3 Reverse micelles Time: 1 h XRD: Size: nanoparticles absent [20] Temperature: 303 K Starting materials:(a) Triton X-100(b) Cyclohexane(c) n-butylalcohol(d) La(NO3)3(aq) e) NaCO3(aq) La2(CO3)3·8H2O Hydrothermal Time: 2–5 days XRD: Pccn a = 8.984 Å b = 9.580 Å c = 17.00 Å [21] Temperature: 773 K Size: nanoparticles absent Prepared by slow hydrolysis of La(CCl3COO)3 La2(CO3)3·1.4H2O Hydrothermal Time: 1 h 30 min Structure unknown [22] Temperature: 368 K Starting material:(a) La2O3 (b) HNO3 (c) Urea La2(CO3)3·1.7H2O Sonochemical Time: 30 min XRD: a = 8.990 Å c = 9.675 Å [23] Temperature: not specified Size: not specified (a) La(OAC)3 (b) Na2CO3 TEM: Size: 25–35 nm Concentration:(a) La(OAC)3: 0.051 M(b) Na2CO3: 0.251 M La2(CO3)3·5H2O Hydrothermal Time: XRD: Pbca a = 9.0167 Å b = 12.842 Å c = 9.6331 Å [24] Temperature: Size: not specified Starting materials:(a) La2O3 (b) HCl(c) Na2CO3 La2(CO3)3·3.4H2O Hydrothermal Time: 3–4 h XRD: P21212 a = 9.57 Å b = 12.65 Å c = 8.94 Å [25] Temperature: 298–308 K Size: not specified Starting materials:(a) LaCl3 (b) NH4HCO3 2 La2O3 Thermal decomposition Time: 2 h P3m1 a = 3.973 Å b = 3.9373 Å c = 6.129 Å [26] Temperature: 1073 K Size: 15 nm Starting material: La(OH)3 nanorods TEM: Size: 23 nm La2O3 Thermal decomposition Time: 2 h XRD: a = 11.347 Å [23] Temperature: 873 K Size: 30 nm Starting material:La2(CO3)3·1.7H2O TEM: Size: 30 nm La2O3 Thermal decomposition Time: not specified Not specified [27] Temperature: 1198 K Starting material:(a) La(NO3)3·9H2O(b) NH4HCO3 La2O3 Thermal decomposition Time: 4 h Not specified [28] Temperature: 1073 K Starting material: La(OH)3 La2O3 Thermal decomposition Time: 2 h P 3 ‾ m 1 $P\overline{3}m1$ a = 3.973 Å b = 3.9373 Å c = 6.129 Å This work Temperature: 873 K XRD: Size: 43.26 nm Starting material: La2(CO3)3·8H2O TEM: Size: 17–34 nm ).

A new method for preparation of RE2(CO3)3 by multi-membrane electroconversion

Preparing rare earth carbonates from rare earth chlorides is a common step in the smelting process for all rare earth ores; however, it produces large amounts of ammoniacal nitrogen wastewater and a chloride-rich precipitate. This study proposes a novel, green and simple process for preparing low-chlorine lanthanum carbonate via a multi-membrane electroconversion approach. The effects of the CO2 flow rate, current density, lanthanum chloride concentration, and electroconversion time on the electroconversion process were systematically explored. Under the optimal process conditions (CO2 flow rate = 0.5 L/min, current density = 25 mA/cm2, LaCl3 concentration = 0.3 mol/L, electroconversion time = 60 min), a current efficiency of 75.77% was obtained, along with a unit energy consumption of 5.44 kW h/kg. X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and laser particle size analysis results indicate that a pure La2(CO3)3·8H2O product is obtained with a median particle size of 6.53 μm and chlorine content of 0.0021%. In addition, scanning electron microscopy and transmission electron microscopy observations indicate that the crystallisation and growth of La2(CO3)3·8H2O conform to the oriented attachment and Ostwald ripening mechanisms. Thus, the proposed multi-membrane electroconversion method provides guidance toward the clean transformation of rare earth chlorides to low-chlorine lanthanum carbonates.

Regulation of Gene Expression Related to Vascular Calcification by Lanthanum Carbonate

Regulation of Gene Expression Related to Vascular Calcification by Lanthanum Carbonate

Spark deposition of lanthanum-carbon composite nanoparticles embedded in a polypropylene membrane for phosphate removal in aqueous solutions

Eutrophication in water, such as rivers or lakes, is becoming increasingly serious. Controlling the phosphate concentration in such waters is the key to solving the eutrophication problem. The use of adsorption methods to limit the level of phosphate in aqueous solutions has the advantages of cost-effectiveness, ease of operation, and selectivity. In this study, a modified polypropylene (PP) membrane was used as the platform for the in-situ deposition of lanthanum-carbon (La-C) composite nanoparticles. Uniform lanthanum (La) and carbon (C) aerosols were deposited on the PP film using spark ablation, and the combined hydrothermal method was used to synthesise the nano-confinement crystal PP-La-C (PLC) for phosphorus removal in an aquatic environment. Because of the nanoconfinement of the PLC, particle agglomeration deactivation was effectively solved, and the doping of C changed the shape of La(OH)3 from particles to ultrafine nano-fibres, which resulted in a larger surface area and more abundant active sites, and the overall adsorption performance was improved. The addition of C reduced the cost, and La proved to be the main active site for phosphate capture. The adsorption test revealed a significant adsorption capability of 194.1 mg⋅P⋅g−1. Three variables, such as reaction time, dose, and original phosphate concentration, were selected and a model for predicting lake water phosphate removal efficiency was developed using the central composite design method. When PLC was used to treat water samples from Lake Qilu (Yunnan, China), the observed removal rate of total phosphorus was 94 %, which is consistent with the model prediction. A series of characterisations established that ligand exchange and multilayer adsorption were the main mechanisms of phosphorus removal.