Solid Salt Research Articles

Supersaturated formulations of poorly soluble weak acid drugs evaluated in rodents; a case study

In the present study we describe a way of working to overcome oral administration challenges in an early preclinical project. As candidate drugs were obtained, the preclinical delivery route was replaced by the intended route of the product and resources were allocated to optimize the oral absorption. Two main approaches were followed in order to formulate a selected weak acid, AZ’403, for oral administration in large scale toxicological studies and the early clinical phases. Both approaches relies on the suppression of precipitation from obtained supersaturated solutions achieved either by amorphous solid dispersions (using hydroxypropyl methylcellulose acetate succinate, HPMC-AS) or crystalline salts (sodium and potassium salts). In vivo studies in rodents were performed to evaluate oral AZ’403 absorption from amorphous and crystalline formulations, using nano- and micro crystalline particles of the neutral form, as references. The oral absorption of AZ’403 formulated using both approaches was significantly higher compared with the references. The improvements in overall exposures were 7–100 times during the investigated conditions. The pharmacokinetic profiles implied that both solid dispersions and crystalline salts of AZ’403 generated supersaturation in the small intestine in rodents and indicated that both approaches may be ways forward for subsequent late stage product development.

Grid-Scale Ternary-Pumped Thermal Electricity Storage for Flexible Operation of Nuclear Power Generation under High Penetration of Renewable Energy Sources

In this work, the integration of a grid-scale ternary-Pumped Thermal Electricity Storage (t-PTES) with a nuclear power generation to enhance operation flexibility is assessed using physics-based models and digital real time simulation. A part of the electricity from the nuclear power generation is delivered to the grid, and the balance is used to power a heat pump that can be augmented by an auxiliary resistive load element to increase the charging rate of the thermal storage. This increases the thermal potential between hot and cold thermal stores (usually solid materials or molten salts inside large storage tanks). The thermal energy is transformed back into electricity by reversing the heat pump cycle. Different transient scenarios including startup, shutdown, and power change for grid-connected operation are simulated to determine the behavior of the hybrid nuclear-t-PTES system operating under variable loads that constitute a departure from conventional, baseload nuclear plant operation schemes. Ternary refers to the three modes operation: (i) heat pump (including heating coil), (ii) heat engine, and (iii) simultaneous operation of heat pump (including heating coil) and heat engine during changeover from pumping to generation or vice-versa. The controllability of t-PTES in the short timescales as a dynamic load is used to demonstrate operational flexibility of hybrid nuclear plants for flexible operation through advanced load management. The integration of t-PTES into nuclear power systems enhances the system flexibility and is an enabler for high penetration of renewable energy resources.

Disproportionation of Pharmaceutical Salts: pHmax and Phase-Solubility/pH Variance.

A multiphasic mass action equilibrium model is used to show that the critical pH in the acid-base disproportionation of a solid salt into its corresponding solid free-base form in aqueous suspensions, widely known as "pHmax", is incompletely interpreted. It is shown that the traditional thermodynamic model does not predict the invariance of pH and solubility during the salt-to-free-base conversion process in an alkalimetric titration. Rather, the conversion entails a range of pH and solubility values, depending on the amount of added excess salt above that needed to form a saturated solution. A more precise definition is proposed for pHmax (pH at the maximum solubility of a eutectic mixture), and three new terms are introduced: pHmin (pH at the minimum solubility of the eutectic mixture), pHδ (disproportionation invariant pH within the eutectic, i.e., the equilibrium pH of a spontaneously disproportionating salt slurry), and pHγ (Gibbs pH at which disproportionation yields equimolar amounts of excess salt and excess free-base solids within the eutectic). Two test compounds with reported multiple salts and the free-base solubility values were selected to illustrate the expanded concepts, the bases WR-122455 and RPR-127963. Also, dibasic calcium phosphate was selected as an ionizable test excipient. The salts are designated in the study as μ-type, when they are thermodynamically stable with respect to spontaneous disproportionation in pure water (e.g., WR-122455 salts), and δ-type, when they are predicted to spontaneously disproportionate in pure water (e.g., RPR-127963 salts). In an alkalimetric titration, when an acidified suspension of a salt of a basic molecule is titrated with a strong base (e.g., NaOH), the passage across the eutectic domain (bounded by pHmax and pHmin) is often characterized by (a) minimum in ionic strength either at pHmax (μ-type salt) or pHδ (δ-type salt) and (b) maximum buffer capacity at pHγ. When the alkalimetric titration is performed with a large excess of added salt, a wide eutectic domain forms: pHmax and pHδ remain invariant, but pHmin and pHγ shift substantially in pH. The acid-base mass action model described here can be useful in predicting the stability of salt formulations in mixtures with excipients that can act as pH modifiers.

A solid iron salt catalyst for selective conversion of biomass-derived C5 sugars to furfural

Salt is widely applied as catalyst but it is difficult to separate the soluble salt from the reaction medium. To solve this issue, in this study, a solid salt catalyst (FeClx-D008) was prepared by using a solid acidic resin (D008) and FeCl3 via a partial ion exchange method as the demonstration of proof of concept. The introduction of FeCl3 onto D008 replaced some Brønsted acid sites with newly generated Lewis acid sites. The synergistic effect of the Brønsted and Lewis acidic sites rendered the catalyst with excellent catalytic selectivity for the production of furfural from C5 sugars (highest yield: 96.3%). The kinetic study showed that the introduction of FeClx onto D008 enhanced the activation energy (AE) from xylose to polymer while lowered the AE from xylose to furfural. The FeClx species could strongly coordinate with the -SO3− group in D008 with the high resistivity to leaching. The successful immobilization of FeClx species on D008 solved the issue for separation of soluble salts from the reaction medium, which is also an attempt for application of resin-based solid salt as the catalyst in acid-catalyzed reactions.

Assessment of instability initiation in exposed salt rock roofs

Stability of rocks is the main requirement for the safe operation of mines. For this purpose, certain measures are applied for the protection and support of underground openings, including roof support design and roof arrangement in the most stable rocks. Stability assessment of underground excavations is largely related to their roof stability. Determination of possible instability conditions in mine roofs governs the choice of support system design and parameters of mine excavations. The Upper Kama Potash Salt Deposit represents a stratified layer of solid salt rocks. Roof instability develops as stratification and roof collapse. The Mohr–Coulomb criterion of coherent rocks is currently used to estimate parameters of a possible damage zone in the exposed roof. This criterion allows evaluating shear plane angles in roof rocks and, as a result, finding parameters of the possible collapse zone. The experience of mining operations in the Upper Kama deposit shows different failure conditions as against the Mohr–Coulomb criterion as the stress state is scarcely included in the criterion used. This study is an attempt to assess parameters of rock exposures by solving a Lame problem in terms of a single mine excavation. The analytical results were compared with the parameters obtained from the plane elasticity solutions by the finite element method. Based on the implemented studies, an engineering approach is developed for the assessment of anticipated instability parameters in exposed roofs in horizontal excavations driven in salt rocks.

Unit weight patterns of overlying rocks above commercial-value salt strata in the Upper Kama deposit

Stability of rocks is the main requirement for the safe operation of mines. For this purpose, certain measures are applied for the protection and support of underground openings, including roof support design and roof arrangement in the most stable rocks. Stability assessment of underground excavations is largely related to their roof stability. Determination of possible instability conditions in mine roofs governs the choice of support system design and parameters of mine excavations. The Upper Kama Potash Salt Deposit represents a stratified layer of solid salt rocks. Roof instability develops as stratification and roof collapse. The Mohr–Coulomb criterion of coherent rocks is currently used to estimate parameters of a possible damage zone in the exposed roof. This criterion allows evaluating shear plane angles in roof rocks and, as a result, finding parameters of the possible collapse zone. The experience of mining operations in the Upper Kama deposit shows different failure conditions as against the Mohr–Coulomb criterion as the stress state is scarcely included in the criterion used. This study is an attempt to assess parameters of rock exposures by solving a Lame problem in terms of a single mine excavation. The analytical results were compared with the parameters obtained from the plane elasticity solutions by the finite element method. Based on the implemented studies, an engineering approach is developed for the assessment of anticipated instability parameters in exposed roofs in horizontal excavations driven in salt rocks.

Effects of Umbilical Cord Blood Stem Cells on Coronary Artery Damage in Mice with Kawasaki Disease By High-Frequency Ultrasound

Objective: to use lactobacillus casein cell wall extract (LCWE) to induce Kawasaki disease (KD) mouse model, and analyse the process of coronary artery damage and effects of umbilical cord blood stem cells by high-frequency ultrasound in small animals. Methods: LCWE was prepared and 18 BALB/c pups were randomly divided into two groups: 15 in KD model group and 3 in the normal control group. KD model was induced by a single intraperitoneal injection of 0.5ml LCWE in the model group, and changes of the coronary artery were observed at 2d, 21d and 30d after the injection, respectively. From the 16th day of modeling, 300 μL PBS was injected intraperitoneally daily in the control group and model group. The hUC-MSCs 300 μL (105/mL) were intraperitoneally injected daily for 10 consecutive days in the stem cell group. The mice were sacrificed in batches on day 2, 15, 21 and 30, and the morphological changes of coronary arteries were observed by echocardiography and histopathology. Results: the change of coronary artery diameter could be accurately measured by high-frequency small animal ultrasound. At 21d, the coronary arteries of the model group were widened compared with those of the control group. At 30d, there was no significant difference between the model group and the previous model group. Histopathology showed slight swelling of the epicardium of aortic valve, mitral valve, right ventricle and atrium, scattered infiltration of a few neutrophils, dilatation of the coronary artery lumen, necrosis and disintegration of a small number of myocardial cells, and significant hyperplasia of local fibrous connective tissue accompanied by solid calcium salt deposits. After hUC-MSCs intervention treatment, B-ultrasound showed a decrease in the main coronary artery diameter, histopathology showed multiple lymphocytes, eosinophilic granulocytes, and mononuclear cell infiltration in the left atrial appendage of mice, and no obvious vascular inflammatory reaction or other obvious abnormalities were observed. Conclusion: high-frequency ultrasound can be used to clearly obtain the coronary artery image of KD mice and dynamically observe the evolution process of coronary artery diameter, which provides more diagnostic basis for the treatment of clinical KD. And hUC-MSCs intervention reduced the pathological lesion of coronary artery inflammation in mice compared with the model group.

Effect of Alkaline Salts on Calcium Sulfoaluminate Cement Hydration.

This work analyzes the effect of the presence of 5 wt.% of solid sodium salts (Na2SO4, Na2CO3, and Na2SiO3) on calcium sulfoaluminate cement (CSA) hydration, addresses hydration kinetics; 2-, 28-, and 90-d mechanical strength, and reaction product microstructure (with X-ray diffraction (XRD), and Fourier transform infrared spectroscopy, (FTIR). The findings show that the anions affect primarily the reactions involved. Ettringite and AH3, are the majority hydration products, while monosulfates are absent in all of the samples. All three salts hasten CSA hydration and raise the amount of ettringite formed. Na2SO4 induces cracking in the ≥28-d pastes due to post-hardening gypsum and ettringite formation from the excess SO42– present. Anhydrite dissolves more rapidly in the presence of Na2CO3, prompting carbonation. Na2SiO3 raises compressive strength and exhibits strätlingite as one of its reaction products.

Investigation of the structure of borehole zones at various stages of development of saline reservoirs with textural wettability

A laboratory and numerical study of the mechanisms that affect the structure and physical properties of the borehole zone of a production well at various stages of development of a saline formation with textural wettability was conducted. It is shown that for the object of study is characterized by the formation of complex borehole vicinity of the structure and dynamic change of properties which define the specific geotechnical effects: desalinization; pinched adscititious water in the pore space; the decompression and the strain on the washed areas; precipitation of solid salt sediment at the moment of breaking through the highly mineralized front of the injected water. The synergetic effect of these effects leads to the formation of complex, including non-monotonic, permeability distribution profiles in the near-well zone.

Production of High Purity Samarium Acetate for Use in Nuclear Area

Samarium is currently used in many applications, such as catalysts, lasers and metal alloys. Samarium is also employed to absorb neutrons in nuclear reactors. In medicine, samarium is used in the form of radioactive 153Sm to produce radiopharmaceuticals. A simple process for the preparation of pure samarium acetate was studied. The raw material, which was used in the form of rare earth carbonates was produced industrially from the chemical treatment of Brazilian monazite. Ion exchange chromatography was performed using a strong cationic resin to fractionate rare earth elements (REE). Under these conditions, 99.9% pure Sm2O3 and yield greater than or equal 60% was eluted by ammonium salt of ethylenediaminetetraacetic acid (EDTA) solution in controlled pH. The EDTA-samarium complex was transformed into samarium oxide, which was subsequently dissolved in acetic acid to obtain the samarium acetate. Molecular absorption spectrophotometry was used to monitor the samarium and sector field inductively coupled plasma mass spectrometry was used to certify the purity of the samarium acetate. The solid salt was characterized by chemical analysis, thermal analysis, infrared spectroscopy and X ray diffraction. The analytical data collected allowed to conclude that stoichiometric formula for the samarium acetate obtained is Sm(CH3COO)3.4.H2O.Keywords: Samarium, Ion exchange, Rare Earth.

A novel and stable hydroxylamine salt generated from betaine hydrochloride and its application in the synthesis of cyclohexanone oxime

AbstractBACKGROUNDHydroxylamine (NH2OH) is an important chemical raw material, which is widely used in large‐scale synthesis of cyclohexanone oxime (COX) for nylon 6 manufacture. At present, inorganic acids are usually employed to stabilize NH2OH to form solid hydroxylamine salts. However, most of these hydroxylamine salts suffer from the problems of serious equipment corrosion, environmental pollution and difficult recovery of the inorganic acids. To address these issues, herein, a novel betaine hydrochloride hydroxylamine (BHA) was formulated and applied for the production of COX.RESULTSThe structure of BHA was identified using experimental analysis and density functional theory calculation. During the synthesis of COX from cyclohexanone (CYC), the BHA exhibited much higher reactivity than that of traditional NH2OH·HCl. Moreover, oximation reaction of CYC and BHA can also be conducted in CH3CN solution. And an almost 100% yield of COX was obtained under the conditions of 30 °C, 0.5 h and 1:1 molar ratio of BHA to CYC. Furthermore, the betaine hydrochloride released from BHA can be easily separated and recycled after the reaction, achieving a green route for the synthesis of COX.CONCLUSIONSA novel BHA was successfully prepared. It shows great advantage for use as an eco‐friendly and green carrier of NH2OH for preparing COX and forming a virtuous cycle. © 2021 Society of Chemical Industry (SCI).

Efficient SO2 Absorption by Anion-Functionalized Deep Eutectic Solvents

In this work, the anion-functionalized deep eutectic solvents (DESs) comprising solid organic salt tetraethylammonium tetrazolate ([N2222][Tetz]) and ethylene glycol (EG) at a molar ratio 1:2 were ...

Energetic, economic and environmental assessment of zero liquid discharge (ZLD) brackish water and seawater desalination systems

The discharge of brine (saline wastewater) from brackish water and seawater desalination plants poses a major threat to the natural environment. This research study presents an energetic, economic and environmental assessment of zero liquid discharge (ZLD) desalination systems in the Eastern Mediterranean. Two scenarios are considered: (i) ZLD brackish water and (ii) ZLD seawater systems, both aimed at producing saleable freshwater and mixed solid salt. Results showed that the energy consumption in scenario 1 (9.48 kWh/m3) is 2.38 times lower than in scenario 2 (22.55 kWh/m3) due to the 7 times lower feed salinity. The differentiation in energy demands is also translated to costs since scenario 2 (US$1.04/m3) is 1.24 times more expensive than scenario 1 (US$0.84/m3). Both scenarios are 3.18 times cheaper than the disposal method of the evaporation pond, while they are in the same cost range as the land application and deep-well injection. Whether only freshwater is sold or both freshwater and mixed solid salt are sold, both scenarios are profitable as the profit ranges from US$215.05/day to US$302.55/day. Concerning CO2 emissions, scenario 1 (5.91–6.45 kg CO2/m3) has lower values than scenario 2 (14.05–15.33 kg CO2/m3) as the energy demanded in scenario 1 is significantly lower.

Beneficiation of saline effluents from seawater desalination plants: Fostering the zero liquid discharge (ZLD) approach - A techno-economic evaluation

Zero liquid discharge (ZLD) and the utilization of saline effluents (brine) for resource recovery have recently attracted interest. A major environmental threat is the discharge of brine from seawater desalination plants. This research study presents two different ZLD systems to utilize brine by recovering not only freshwater, but also solid salts with commercial value. Two ZLD systems are considered in this techno-economic assessment: (a) system 1, which produces both freshwater and mixed solid salt, and (b) system 2, which produces freshwater, mixed solid salt, and pure solid salt (NaCl). The results showed that in terms of specific energy consumption (SEC) and freshwater cost, system 2 was costlier than system 1. In particular, system 2 (31.81kWh/m3) had a 1.4 times higher SEC than system 1 (22.55kWh/m3) as well as system 2 (US$1.37/m3) had a 1.32 times higher freshwater cost than system 1 (US$1.04/m3). Nonetheless, system 2 was 1.52 times more profitable than system 1 as pure NaCl production increased revenue significantly. Moreover, systems 1 and 2 were even profitable exclusively from the selling of freshwater. Overall, the results showed that both ZLD systems are promising options for sustainable brine management and utilization that follow the circular economy model.

Chemical and Hygroscopic Characterization of Surface Salts in the Qaidam Basin: Implications for Climate Impacts on Planet Earth and Mars

Salt particles play important roles in many atmospheric processes due to their high hygroscopicity. Saline lakes and playas are sources of salt particles, which are normally mixed with mineral dust that can be transported over long distances. In this study, salt samples collected from four saline lakes and surrounding playas in the Qaidam Basin are studied for their physicochemical properties, focusing on the chemical compositions and hygroscopicity. The salt samples include brines, lakebed salts, crust salts, and crystallized brines. Thermodynamic models are used to explain the precipitating and hygroscopic behaviors based on ionic compositions of dissolved saline solutions. Regarding the ionic compositions, the crystallized brines are similar to the complex mineral compositions of brines, while the natural solid salts, including lakebed salts and crust salts, show very distinct composition differences. The main difference between brines and natural solid salts is the presence of Mg2+ and SO42–, which are primarily found in brines but not in the solid phases. Moreover, all the crust salts are dominated by NaCl regardless of the chemical compositions of the nearby saline lakes. Positive matrix factorization is applied to the ionic concentrations, and the results show that solid salts and brines are governed by different factors. The pH of brines correlates with Mg2+ concentrations and is potentially influenced by ambient CO2 uptake. The hygroscopicity experimental results and thermodynamic model outcomes show that the water uptake of different salt types is controlled by different salt components, that is, crystallized brines are controlled by MgCl2 and natural salts are governed by NaCl and KCl. The characterizations of saline lake and playa salts improve the understandings of the roles that surface salts potentially play in the climate systems of both Planet Earth and Mars.

A Novel Synthesis Pathway Towards Rare Earth Fluorides by Using Liquid and Solid State Hexafluorophosphate Salts

This work concerns different methods to synthesize rare earth fluorides by using liquid and solid state hexafluorophosphates. Various [PF6]− sources were compared, i.e. [BMIM][PF6], [TBA][PF6] and KPF6. Furthermore, the required reaction times and temperatures have been determined by XRD measurements. It turned out that [TBA][PF6] reacts even in the solid state at moderate temperatures to yield single phase LaF3. The use of hydroxides and oxides instead of the commonly employed nitrates as rare earth educts was successfully attempted. The reaction with rare earth hydroxide showed some peculiarities which were traced back to the specific reaction between HF and OH−. The reaction between [TBA][PF6] and La(OH)3 was studied in detail via the determination of oxygen and nitrogen concentrations as well as solid-state 19F and 139La nuclear magnetic resonance (NMR).

Evaluation of the in vitro growth of perolera pineapple (Ananas comosus) explants using organogenesis technique

From an economic standpoint, pineapple (Ananas comosus) is one of the most important fruits in Colombia. A decade ago, the Perolera variety was the most cropped cultivar of the Santander department, however, the variety has been displaced considerably due to the lack of technical extension services and theintroduction of new varieties. This research project was carried out with the intention to conserve the speciesthrough the development of in vitro pineapple explants using the organogenesis technique. Meristemsthat have been extracted from the crown of the Perolera pineapple variety were used for this purpose. Four disinfectant treatments were evaluated by looking at the different kinds of disinfectant exposure times.The treatment that gave the best results in terms of contaminant-free explants was the T2: Commercialdetergent + Tween 80 for 8 minutes, ethyl alcohol at 70% for 1 minute and sodium hypochlorite at 1,5% over10 minutes, with a contamination rate of 7% and 93% of the explants thriving. For the establishment phase,it was found that the medium MS MEP1 with 100% solid salts supplemented with 2000 ul/L BAP - 1000 ul/L ANA - 1000 ul/L AIA and 500 ul/L thiamine enabled 90 % of the pineapple explants to continue developing four weeks after planting. Similarly, the medium containing 3000 ul/L of BAP for the multiplication phase permitted an average proliferation of 4.62 shoots with 9.12 leaves per shoot and a length of 2.25 mm.

Recent trends of self-emulsifying drug delivery system for enhancing the oral bioavailability of poorly water-soluble drugs

The oral route is the most popular route for the clinical administration of drugs to treat various diseases. Before a drug is absorbed into the blood circulation, it must undergo dissolution and permeation. However, most drugs exhibit poor aqueous solubility, and their limited absorption leads to low oral bioavailability. The solubility of hydrophobic drugs can be improved by various ways, such as solid dispersion, salt formation, pH modification, and self-emulsifying drug delivery system (SEDDS) use. Among them, the SEDDS has garnered attention during recent years as it improves oral bioavailability, reduces drug dose, and increases drug protection from unsuitable environment in the gastrointestinal tract. SEDDS comprises lipid-based formulations. It can solve the problems related to the dissolution and bioavailability of the Biopharmaceutics Classification System Class II and IV drugs. Depending on the preparation procedure, drug-loaded SEDDS can be divided into micro- (SMEDDS) and nano- (SNEDDS) formulations. In this review, we summarize the classification system of lipid formulations, the mechanism underlying improved oral drug absorption by SEDDS, and recent advances in the SEDDS. The SEDDS is a potential formulation for drug delivery. Owing to its small particle size, large surface area, high encapsulation efficiency, and high drug loading, the SEDDS can improve the rate and extent of oral absorption by maximizing drug solubility in the intestinal absorption site. Moreover, because of the lipid-based formulation of SEDDS, it can stimulate and enhance lymphatic transport of drugs to avoid hepatic first-pass metabolism, and thus improve their bioavailability.

Solubility Product Constant Governs Multivalent Protein Phase Separations

Liquid-liquid phase separation (LLPS) has emerged as an intriguing phenomenon inside living cells. The phase-separated droplets, where specific biochemical events can take place and which also buffer cytosolic concentrations, are composed of weakly binding multivalent proteins or nucleic acids. Despite the explosion of this field of study, a general purpose quantitative principle to predict phase separation for multicomponent (“heterotypic”) binders has yet to emerge. In this study, we used non-spatial (NFSim) and spatial (SpringSaLaD) network-free rule-based modeling to determine the concentration threshold for LLPS as a function of molecular valencies. Remarkably, the simulations suggest that the phase separation behavior conforms to the solubility product constant (Ksp), familiar for ions in solution in equilibrium with solid salts: as long as the product of monomer concentrations exceeded the Ksp, the system showed phase separation - irrespective of the individual monomer concentrations. The solubility product constant decreases as the molecular valency of binding partners increases, shifting the concentration threshold to lower values. When we mixed molecules with different valencies, penta-valent and tri-valent, for example, Ksp followed an expression determined by ideal stoichiometries, similar to that of a mixed-valent salt like Al2(SO4)3. Spatial simulations revealed the importance of molecular flexibility and inter binding sites distance of the multivalent molecules. When the inter-site distances of a heterotypic tetravalent molecular pair are exactly matched, a prevalence of dimer (“dimeric trap”) was observed. A rigid molecular pair, with equal inter-site distances, produced this “dimeric trap” more prominently, while unequal inter-site distances disrupted the trap and formed large clusters that displayed a Ksp similar to that found in the non-spatial simulations. Thus our study establishes a general principle underlying the concentration threshold for phase separations, the Ksp, and how molecular structure can shape it. (Support: NIH grants R24GM137787 and R01GM132859)

Characteristics of water-soluble inorganic aerosol pollution and its meteorological response in Wuhan, Central China

Due to the rapid economic development in Central China, PM2.5 (particles not larger than 2.5 μm) pollution is serious in recent years. To fully understand the causes of PM2.5 in this region, we conducted a long-term tracking (2015–2018) on water-soluble inorganic ions (WSIIs) in PM2.5, including sulfate (SO42−), nitrate (NO3−), ammonium (NH4+), chlorine (Cl−), potassium (K+), calcium (Ca2+), sodium (Na+), and magnesium (Mg2+). Results indicate that each ion has significant seasonal variations, with the maximum concentration in winter and minimum in summer. The secondary inorganic aerosols (SIAs) have remarkably higher concentrations in haze periods than non-haze periods, which indicates that the outbreak of haze is closely related to the massive generation of SIAs. Moreover, each ion shows a different response to the variation of meteorology, implying the different formation mechanisms. Generally, high pollution levels of Ca2+, Mg2+, K+, Cl−, and Na+ are correlated to prevailing winds, suggesting the significant contribution of regional transport. High concentrations of SIAs are usually accompanied by the low temperature (T < 15 °C), high relative humidity (RH > 60%), and calm wind, which means they are mainly locally generated. Under conditions with low T and high RH, more gaseous sulfur and nitrogen tend to be converted into solid inorganic salts, proved by the higher oxidation efficiency. Different to NO3−, SO42− is also easily generated at high T through photochemical oxidization. This study interprets fine particle pollution from the perspective of particle composition, and the results provide an reference for regional air pollution prevention.