Tetrabutylammonium Hydrogen Sulfate Research Articles

Validation of an Ion-Pair Reverse Phase High-Performance Liquid Chromatography Method for the Detection of Major Components and Related Substances in Diquafosol Sodium Eye Drops.

A simple, feasible, isocratic elution, and stable reversed-phase high performance liquid chromatography method was established and verified. The chromatographic conditions are as follows: EF-C18H, 4.6 × 250 mm, 5 μm column; column temperature 30 °C; for the mobile phase 27.2 g of KH2PO4 and 8.5 g of tetrabutylammonium hydrogen sulfate were taken, 2500 mL of water was added to dissolve, and the pH was adjusted to 6.7 with phosphoric acid:methanol solution with a ratio of 84:16 (V:V). The flow rate was 1.0 mL/min; the injection volume was 10 μL; and the wavelength was 262 nm. According to the current ICH guidelines, the developed method was verified, and the system suitability, specificity, LOD, LOQ, linearity, range, accuracy, repeatability, durability, and solution stability of the proposed method were verified. The validation results demonstrated that the LOQ for the method was 0.05% and the LOD was 0.02%. The content was detected within the concentration range of 300 to 900 μg/mL. The relationship between concentration and measurement was linear, with an r2 of >0.999. The concentration of impurities ranged from 0.3 to 4.5 μg/mL. A good linear correlation was observed within the range of g/mL, with a coefficient of determination r2 greater than 0.999. The accuracy and repeatability met the specified criteria.

Dispersion of asphaltene aggregates by zwitterionic surfactants: influence of cations structure

The precipitation and deposition of asphaltenes are significant challenges in the petroleum industry resulting in substantial costs. A practical approach to addressing this issue is to use chemicals as inhabiting and dispersing agents. Zwitterionic surfactants are interesting materials in this field. In this study, three zwitterionic compounds including 2-(1-methyl-1H-imidazol-3-ium-3-yl)butane-1-sulfonate (MIBS), 4-(pyridin-1-ium-1-yl) butane-1-sulfonate (PBS), and 4-(tributylammonio)butane-1-sulfonate (TBBS) were synthesized and characterized by FT-IR, NMR spectroscopy, thermogravimetric, and differential thermal analysis. The ability of these zwitterions to prevent asphaltenes precipitation was investigated using interfacial measurements, ultraviolet spectroscopy, quartz microbalance analysis, particle size analysis, and optical microscopy. The results showed that the MIBS zwitterion, which contains an imidazole cation, was the most effective in dispersing asphaltene aggregates compared to the other two zwitterions. For instance, the UV spectroscopy results showed that the dispersion indexes for MIBS, PBS, and TBBS were 52.8%, 29.9%, and 16.3%, respectively. In addition, the size of asphaltene particles reached from 2179 nm to 622, 1489, and 2038 nm for MIBS, PBS, and TBBS, respectively. Finally, a comparison between the performance of these zwitterions with sodium dodecyl sulfonate (SDS) and tetrabutylammonium hydrogen sulfate (TBAHS) showed the following trend: MIBS (90.5%)> PBS (79.4%) > TBAHS (75%)> SDS (73.9%) >TBBS (46%).

Synthesis and characterization of acidic deep eutectic solvents based on p-Toluenesulfonic acid

There is growing interest in identifying suitable, less hazardous deep eutectic solvent (DES) alternatives for conventional solvents and catalysts, particularly acid catalysts which can be volatile and highly corrosive. In this study, novel acidic DESs based on mixtures of either tetrabutylammonium hydrogensulfate (TBAHS) (DES1) or tetraphenylphosphonium bromide (TPPB) (DES2) with p-toluenesulfonic acid monohydrate (PTSAM) are prepared. The properties of these DESs were investigated using multiple analytical techniques, including density, viscosity, conductivity and diffusion measurements. DES1 formed a room-temperature liquid, whereas DES2 melted at 337 K at its eutectic point. Hammett acidity studies revealed that both the DESs show super acidity (H0DES1 = -2.91 and H0DES2 = -1.89) even when present in relatively dilute (40 mM) aqueous solutions. Conductivity measurements established that both DESs show good ionicity at elevated temperatures based on a Walden plot, although DES2 displayed reduced ionicity close to its melting point. Equilibrium structural arrangements for these DESs are proposed based on findings, with the formation of a complex hydrogen-bonded anion and isolated cation. These DESs are proposed as potential replacements for ionic liquids, and existing acid catalysts in acid catalyzed reactions.

Development and antibacterial investigation of Linezolid loaded SPIONs and HPLC method development for quantitative analysis of Linezolid.

Linezolid (LNZ) is extremely prone to resistance. The development of resistance to LNZ should be taken into consideration when selecting this drug as a therapeutic option. By considering the hypothesis that reactive oxygen species (ROS) generated by iron oxide nanoparticles (MNPs) could kill the infecting bacteria. So, we hypothesized the synergistic antibacterial effect of iron oxide nanoparticles and LNZ. To study the release and antibacterial effects of LNZ loaded superparamagnetic iron oxide nanoparticles (SPIONs) on Staphylococcus aureus and Streptococcus pneumoniae. Ferrofluid containing SPIONs was synthesized via chemical co-precipitation method and stabilized by sodium lauryl sulphate (SLS). SPIONs were then loaded with LNZ and characterized for particle size, FT-IR, XRD, and entrapment efficiency. Further antibacterial activity of SPIONs and LNZ-loaded SPIONs was investigated. For the in-vitro release findings, a HPLC analytical method development and validation was performed. Isolation of LNZ was accomplished on a C-18 column with methanol: TBHS (Tetra butyl ammonium hydrogen sulphate, 50:50 v/v). The eluate was monitored at 247 nm with retention time of 4.175 min. The MNP's DLS measurement revealed monodispersed particles with an average size of 16.81 ± 1.07 nm and PDI 0.176 ± 0.012. In optimized formulation, 25 ± 1.75% (w/w) of the drug was found to be entrapped. XRD revealed uniform coating of oleic acid covering the entire magnetic particles surface with no change in its crystallinity. An effective antimicrobial activity was observed at the lowered dose of drug. A robust HPLC method was developed to quantify the LNZ in MNPs and outcomes showed that the reduced dose of LNZ incorporated in SPIONs was able to show similar activity as the marketed product. Successfully reduction of dose of LNZ was established with the aid of biocompatible MNPs to attain the equivalent antibacterial activity.

New stability indicating liquid chromatographic method for the estimation of Valsartan in pharmaceutical dosage forms

Valsartan is an orally active antihypertensive agent which belongs to the category of angiotensin II type I receptor antagonists. Valsartan is used for the treatment of heart failure, hypertension, myocardial infraction and diabetic nephropathy. A new stability indicating RP-HPLC was proposed for the quantification of Valsartan by using an ion-pairing agent, tetra butyl ammonium hydrogen sulphate. Mobile phase mixture consisting of 10 mM tetra butyl ammonium hydrogen sulphate and methanol (25: 75, v/v) was selected with a flow rate of 1 ml/min using Agilent C18 column (Detection wavelength 250 nm). The LOD and LOQ were found to be 0.0291 μg/mL and 0.0897 μg/mL respectively. Linearity was observed over the concentration 0.1-50 μg/mL with linear regression equation, y = 36571x + 13532 and the method is precise, accurate and robust. Stress degradation studies were performed and the method was found to be selective and specific.

Validation d’une méthode d’identification et de dosage de l’oxytetracycline dans des médicaments à usage vétérinaire par CLHP-DAD

Oxytetracyclin (OTC) is a broad-spectrum antibiotic from the bacterial aromatic polyketide family. A simple and rapid method of identification and assay of this molecule in veterinary medicinal products was validated. This is a high-performance liquid chromatography (HPLC) method coupled with a diode array detector (DAD). The mobile phase was a mixture of 50 g of tertiary butyl alcohol, 60ml of phosphate buffer (pH 7.5), 50ml of tetrabutylammonium hydrogen sulfate solution, 10ml of disodium edetate solution and enough water for 1000 ml. The flow rate was set at 1ml/min, wavelength detection at 254 nm using a L1 column (C18, 4.6 mm × 25 cm, 5um). The results obtained showed that the method was specific, linear with a correlation coefficient equal to 0.9902 in the concentration ranged from 0.176 mg/ml to 0.264 mg/ml, precise with relative standard deviations less than 5% and accurate with recovery rates between 97.83 % and 101.37 %. The proposed method was valid and can be used routinely to identify and quantifiy oxytetracyclin in veterinary medicines.

A new stability indicating RP-UFLC method for the quantification of Gemifloxacin tablets using an ion pairing agent

Gemifloxacin is a new broad-spectrum quinolone antibacterial with activity against both Gram-negative and Gram-positive organisms. A new stability indicating RP-UFLC method was proposed for the estimation of Gemifloxacin in pharmaceutical dosage forms (tablets). Shimadzu Model CBM-20A/20 Alite UFLC system with PDA detector and Zorbox C18 column were used for the chromatographic study. Mobile phase mixture consisting of Tetra butyl ammonium hydrogen sulphate and Acetonitrile in the ratio 68: 32, v/v with a flow rate 0.8 mL/min was chosen for the chromatographic elution of Gemifloxacin (Detection wavelength 273 nm). The method was linear over the concentration range 0.02-200 mg/ml with linear regression equation, y = 207068x + 19935 (R² = 0.9999). The LOD and LOQ were found to be 0.0553 mg/ml and 0.1693 respectively. Forced degradation studies were performed and the method was validated as per ICH guidelines.

Application of GC-MS and LC-MS techniques for direct analysis of amines in pharmaceutical substances

Organic volatile chemicals such as amines are often not completely removed by practical manufacturing techniques and consequently their low levels are present in most pharmaceuticals. Based on good manufacturing practices and for the safety of the patients the level of hazardous for human health amines in pharmaceuticals have to be strictly controlled. Moreover, analysis of volatile amines in drug product has become recently an emerging topic of interest for analytical chemists since such residual impurities as: secondary amines, tertiary amine and other amine derivatives (in certain condition) have been reported to be a precursors of carcinogenic N-nitrosamines (NAs). In this study we present five new methods for control of such amines as: tert-butylamine (TBA), pyrrolidine, 4-fluoroaniline (4-FA), diisopropyl-ethylamine (DIPEA) and tetrabutylammonium hydrogensulfate (TBAHS) in pharmaceutical active ingredients (APIs) using GC-MS and LC-MS techniques. The validations results clearly demonstrate that the analytical procedures are suitable for their intended purpose. All revealed validations results meet the requirements of the ICH Q2R1 validation guidelines and the Q3A R2 guideline for residual impurities.

Highly efficient dual-electrode exfoliation of graphite into high-quality graphene via square-wave alternating currents

Scalable production of high-quality graphene nanosheets is urgently needed to realize its practical applications. Here, we show that electrochemical dual-electrode exfoliation via alternating current can effectively produce high-yield solution-processable graphene. The selected molecule, tetrabutylammonium hydrogen sulfate, has the ability to diminish anodic oxidation damage to structures while also allowing for simultaneous intercalation of anion and cation species. Additionally, repeated intercalation of cations and anions with alternating current accelerates the ion intercalation and exfoliation process, leading to highly efficient graphene production with minimum destruction. After precisely controlling the intercalation process, high-yield graphene (88.6%) with uniform thickness distribution (77%, 1–3 layers) was achieved. Meanwhile, as-prepared graphene exhibits outstanding electrical conductivity (>6 × 104 S m−1), a considerably high C/O ratio of > 47.2, and a very low defect density (ID/IG < 0.045). Remarkably, the up-scaled manufacturing technique not only achieves a record high production rate (over 80 g h−1), but also improves upon the best-reported graphene quality and exfoliation efficiency (by > 60%). This rapid and scalable method will facilitate the widespread manufacture of high-quality graphene and open up a myriad of potential uses.

Two-Stage Evolution of Gamma-Phase Spherulites of Poly (Vinylidene Fluoride) Induced by Alkylammonium Salt.

We investigated the evolution of the γ-phase spherulites of poly(vinylidene fluoride) (PVDF) added to 1 wt% of tetrabutylammonium hydrogen sulfate during the isothermal crystallization at 165 °C through polarized optical microscopy and light scattering measurements. Optically isotropic domains grew, and then optical anisotropy started to increase in the domain to yield spherulite. Double peaks were seen in the time variation of the Vv light scattering intensity caused by the density fluctuation and optical anisotropy, and the Hv light scattering intensity caused by the optical anisotropy started to increase during the second increase in the Vv light scattering intensity. These results suggest the two-stage evolution of the γ-phase spherulites, i.e., the disordered domain grows in the first stage and ordering in the spherulite increases due to the increase in the fraction of the lamellar stacks in the spherulite without a change in the spherulite size in the second stage. Owing to the characteristic crystallization behavior, the birefringence in the γ-phase spherulites of the PVDF/TBAHS was much smaller than that in the α-phase spherulites of the neat PVDF.

Procoagulant substances and mechanisms of hemostatic herb Eclipta alba

Eclipta alba, as one of the traditional Chinese hemostatic herbs, is often used to treat hemorrhagic diseases. However, the procoagulant components and mechanisms of the herbs are still unknown. In the present study, mixed solvents and macroreticular resin were used to obtain procoagulant extract (PE). The main procoagulant compounds in the extract were further isolated and identified as luteolin 7-sulfate and eclalbasaponin I. Sulfated flavonoids were synthesized by tetrabutylammonium hydrogen sulfate using dicyclohexylcarbodiimide as the medium. Both PE and sulfated flavonoids could agglutinate erythrocytes and flocculate fibrinogen independent of plasma in a dose-dependent manner. Eclalbasaponin I could only agglutinate erythrocytes. PE and sulfated flavonoids could shrink subcutaneous capillaries. Acid condition could promote the procoagulant activity (PA) of PE, eclalbasaponin I, and sulfated flavonoids significantly. PE and sulfated flavonoids exhibited much higher solubilities than Yunnan Baiyao powder, and showed tremendous potential application values in developing hemostatic drugs of treating gastrorrhagia and trauma.

Dietary intakes of trihalomethanes and haloacetic acids from ready-to-eat vegetables in taiwan.

Chlorine-based disinfectants are often used to sanitize fruit and vegetables to produce a product called ready-to-eat (RTE) vegetables. During the disinfection process, disinfection byproducts (DBPs), such as trihalomethanes (THMs) and haloacetic acids (HAAs), might be formed via chlorination. To determine the amounts of DBPs that occur in RTE vegetables in Taiwan, an analytical method which can detect THMs and HAAs simultaneously was developed for this study. For HAAs, dimethyl sulfate (DMS) was first added into the sample as derivatization reagent and tetrabutylammonium hydrogen sulfate (TBA-H2SO4) was used as the ion-pairing agent to improve the derivatization process. Afterwards, the solid-phase microextraction (SPME) procedure coupled with gas chromatography with tandem mass spectrometers (GC/MS/MS) was performed to measure the HAAs derivatives and THMs in the sample. A total of 92 single RTE ingredients were analyzed in this study. Among various THMs and HAAs, the results showed that dibromochloromethane (21%) and dichloroacetic acid (12%) had the highest detection rates, respectively. Compared with fruits, vegetables were more easily to contain DBPs. For adults in Taiwan, the maximum daily exposure of THMs and HAAs estimated via the consumption of RTE vegetables were 28.53 and 77.83 μg, respectively. The findings from this study suggest that the exposure of DBPs from RTE vegetables is an important food safety issue in Taiwan.

Green synthesis of benzaldehydes by the selective oxidation o benzyl alcohols using hexacyanoferrate (III) and bromate under phase transfer catalysis

The selective oxidation of benzyl alcohols and substituted benzyl alcohols was carried out in greener solvents like ethyl acetate and toluene by hexacyanoferrate (III) and bromate ions under phase transfer catalysis. Various phase transfer catalysts like tetrabutylphosphonium bromide, tetrabutylammonium bromide, tetrabutylammonium hydrogen sulphate, cetyltrimethylammonium bromide and tricaprylmethylmmonium chloride were used. A pinch of sodium tungstate dihydrate is added as a co-catalyst when bromate is used an oxidant and hexacyanoferrate (III) is used in presence of mineral acids. The products obtained were precipitated as their 2,4- dinitrophenylhydrazone, purified, weighed and the yield was found to be &gt; 90 %. The products were recrystallized in ethanol and analyzed by melting point and by various spectral techniques. It was proved that corresponding benzaldehydes were formed and there was no further oxidation to corresponding acids. All the catalysts were found effective in bringing out the reaction but based on yield and ease of reaction, the order of reactivity is tricaprylmethylammonium chloride &gt; tetrabutylphosphonium bromide &gt; tetrabutylammonium bromide &gt; tetrabutylammonium hydrogen sulphate &gt; cetyltrimethylammonium bromide. The selective oxidation of benzyl alcohols is very difficult to proceed in organic solvents without the aid of a phase transfer catalyst. Yield of products is found to be slightly more in ethyl acetate than that in toluene due to difference in polarity.

New chloroacetic acid-based deep eutectic solvents for solubilizing metal oxides

In this work, new chloroacetic acid-based deep eutectic solvents (DESs) were prepared from the tetraethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium bromide, and tetrabutylammonium hydrogen sulfate as a hydrogen bond acceptors (HBAs) in combination with chloroacetic acid as a hydrogen bond donor (HBD). The prepared deep eutectic solvents were characterized by measuring their physical properties such as density, sound velocity, electrical conductivity, viscosity, refractive index, and surface tension with the variation of temperature. The new deep eutectic solvent was applied for solubilizing Fe3O4, CuO, ZnO, and PbO metal oxides. The obtained solubilizing data was compared with the other deep eutectic solvent based on the different hydrogen bond donors and acceptors which were used for the solubility of metal oxides.

Improvement of the viscoelastic and thermal properties of polyvinyl acetate reinforced with organophilic clay (Algerian MMT)

Polyvinyl acetate (PVAc) has many favorable characteristics: it is non-toxic, harmless, easily producible, inexpensive, practical to apply and environmentally friendly, the same for clay (maghnite) which is a natural nanomineral, source of a large number of raw materials; it is also inexpensive and accessible. The present study shows the synthesis of PVAc with a molar mass Mn = 120,224 g / mol determined by analysis by gel permeation chromatography and the synthesis of organophilic clay (TBA-maghnite) derived from cation exchange of sodium-clay with Tetrabutylammonium hydrogen sulfate which is characterized by short chains, this exchange has been proven with X-ray diffraction (XRD). These clays were also characterized by infrared spectroscopy and scanning electron microscopy (SEM). The nanocomposites polymer clay NCPCs were prepared by intercalation of the PVAc polymer within the sheets of organophilic clay under a process of intercalation in solution, The mixture was carried out with different percentages of TBA-Maghnite 1 wt.%, 3 wt.% and 4 wt.%. The exfoliated nanocomposites (PVAc / TBA-Maghnite) were obtained at a concentration of 1 wt.% and 3 wt.%, the Different PVAcNCs were characterized using elemental analysis FTIR, XRD, SEM and dynamic light scattering. The mechanical dynamic study has been well determined in this work. The thermal properties of the nanocomposite were investigated using differential scanning calorimetry and thermogravimetric analysis. PVAcNCs showed better viscoelastic property and good thermal stability compared to pure PVAc.

Copper(II) Acetylacetonate/Tetrabutylammonium Hydrogen Sulfate: A New System for Decarboxylation of Aromatic Carboxylic Acids under Amine‐Free Conditions

AbstractA new system for decarboxylation of aromatic carboxylic acids under amine‐free conditions has been developed. In situ generated copper nanoparticles (Cu NPs) stabilized by tetrabutylammonium hydrogen sulfate (TBAHS) were found to catalyze the decarboxylation of aromatic carboxylic acids under amine‐free conditions. Ortho‐substituted benzoic acids bearing electron‐deficient and electron‐rich groups were effectively decarboxylated under these conditions whereas meta‐ and para‐substituted benzoic acids were less reactive and gave moderate yields of desired decarboxylated products.

A simple isocratic LC method for quantification of trace-level inorganic degradation impurities (ferricyanide, ferrocyanide, nitrite, and nitrate) in sodium nitroprusside injection and robustness by quality using design approach.

This study developed and validated a trace-level quantification inorganic impurities method using reversed-phase HPLC and performed the robustness check using quality-by-design approach by varying the multiple factors simultaneously. This method is economical and simple and exhibits its stability-indicating nature [for the determination of ferrocyanide ([Fe(CN)₆]4- ), ferricyanide ([Fe(CN)6 ]3- ), nitrate (NO3 - ), and nitrite (NO2 - )] in sodium nitroprusside (SNP) drug substance and liquid dosage form. Chromatographic separation was achieved using a USP L43 column (ACE PFP, 150×4.6 mm, 3 μm) with a simple isocratic elution. The buffer consists of potassium dihydrogen phosphate (50 mM), tetrabutylammonium hydrogen sulfate (9 mM), and tetrabutylammonium hydroxide (25 mM). The buffer pH was adjusted to 7.2 with tetrabutylammonium hydroxide. The mobile phase was mixed with the buffer and acetonitrile (68:32 v/v). The flow rate was 0.8 mL/min, column temperature was maintained at 30°C, and injection volume was 5.0 μL. The SNP impurities were monitored at 225 nm using a UV detector. Further, the method was validated per the International Council for Harmonisation (ICH) guidelines, and forced degradation studies were carried out under different stress conditions. The detector responses were plotted against concentrations, and correlation was linear (r > 0.999) over the range of 0.8-7.5 μg/mL for ferricyanide; 1.0-37.5 μg/mL for SNP; and 0.2-7.5 μg/mL for ferrocyanide, nitrite, and nitrate. The method repeatability was established for all the impurities with relative standard deviation (%), and the results were found to be less than 2.0.

A New stability indicating RP-HPLC method for the estimation of Gefitinib tablets using an ion pairing agent

Gefitinib is an anticancer drug used for the treatment of lung cancer, breast cancer and prostate cancer. A new stability indicating RP-HPLC method was proposed for the estimation of Gefitinib in pharmaceutical dosage forms (tablets). Shimadzu Model CBM-20A/20 Alite HPLC system with PDA detector and Agilent C18 column were used for the chromatographic study. Mobile phase mixture consisting of Tetra butyl ammonium hydrogen sulphate and Methanol in the ratio 50:50, v/v with a flow rate 0.8 mL/min was chosen for the chromatographic elution of Gefitinib (Detection wavelength 340 nm). The method was linear over the concentration range 0.1-80 mg/mL with linear regression equation, y = 70782x + 6171.6 (R² = 0.9999). The LOD and LOQ were found to be 0.2931 mg/mL and 0.8947 mg/mL respectively. Stress degradation studies were performed by exposing Gefitinib to various stress conditions and the method was validated as per ICH guidelines.

Development, validation, and application of a new method for the quantitative determination of monohydrogen-substituted perfluoroalkyl carboxylic acids (H–PFCAs) in surface water

Per- and polyfluoroalkyl substances (PFASs) are a large and diverse class of chemicals. While some have been phased out internationally due to concerns over their human and environmental health risks, novel alternative PFASs continue to be manufactured and detected in environmental samples. The occurrence and fate of these alternatives remain poorly understood. The present study investigated the occurrence of an emerging class of PFAS alternative, the monohydrogen-substituted perfluoroalkyl carboxylic acids (H–PFCAs), in conjunction with the more well-known PFCAs. A weak anion exchange solid phase extraction-liquid chromatography tandem mass spectrometry method for quantitative determination of H–PFCAs in surface water was developed, validated, and applied on samples collected from the Netherlands. To improve chromatography, especially for short-chain (H-)PFCAs, an ion-pairing agent, tetrabutylammonium hydrogen sulphate, was used. The method was validated for linearity (R2 > 0.99), instrumental detection limits (0.01–0.09 ng/mL), method detection limits (0.03–0.75 ng/mL), matrix effects (<20%), percent absolute- and relative recovery (57–121%), trueness (130-80%), repeatability (<20%), and within-lab reproducibility (<20%). Eleven out of fourteen PFASs showed acceptable results. Application of the newly validated method to surface water throughout the Netherlands revealed trace levels of H–PFCAs (including two new H–PFCAs) and high concentrations of PFCAs.

Effects of buffer salt types and non-counter ions of ion-pair reagents on the retention behavior of strongly ionized acid compounds in ion-pair reversed-phase liquid chromatography

在离子对反相液相色谱(IP-RPLC)分析中,溶质保留受对离子(counter ion)的影响比较受人关注,但鲜有研究流动相中缓冲盐类型和离子对试剂中非对离子(non-counter ion)对溶质保留行为的影响。鉴于此,该文以14种磺酸化合物为研究对象,甲醇为有机调节剂,分别考察了3种缓冲盐体系(磷酸二氢铵、氯化铵和乙酸铵)和5种离子对试剂体系(四丁基溴化铵、四丁基磷酸二氢铵、四丁基硫酸氢铵、四丁基硝酸铵和四丁基乙酸铵)下强离解酸性化合物的IP-RPLC保留行为,通过比较不同流动相条件下得到的溶质log kw(100%水相作流动相时的保留因子)、S(线型溶剂强度模型线性回归得到的常数),以及CHI(色谱疏水指数,log kw/S),寻找保留行为规律。研究表明,流动相中的缓冲盐类型和离子对试剂非对离子均会影响化合物的log kw和S值,所有化合物在氯化铵缓冲盐体系下具有最大的log kw值。相对于无机阴离子,离子对试剂中弱离解性有机阴离子(乙酸根)的存在有利于增加磺酸化合物的S值。通过对比不同条件下的保留行为,推测磺酸化合物的IP-RPLC保留机理中同时存在着离子对模型和动态离子交换模型。与log kw和S值不同,化合物的CHI值受缓冲盐类型以及离子对试剂非对离子的影响较弱。此外,研究发现化合物的表观正辛醇/水分配系数(log D)与log kw、S、CHI之间均具有良好的线性相关性。不同缓冲溶液和不同离子对试剂非对离子条件下获得的log kw和S值存在着一定的差异,而CHI值相对稳定,因此,CHI更适用于IP-RPLC中定量结构-保留行为关系模型的建立。