N-lauroylsarcosine Sodium Research Articles

Production of high value-added filler from harmful dust of marble industry using N-sodium lauroyl sarcosinate surfactant as a new flotation collector

AbstractIn the stone industry, about 73% of the total production is generated as solid waste. In the processing phase, only 20% is produced as harmful ultra-fine sawdust sludge. In the Turah area, Cairo, Egypt, an estimated 448,000 tons are produced annually. About 60% of the total production of dimension stones is carbonate stones. The objective of this study is to properly dispose of the ultrafine pollutants and produce value-added products. The ultrafine marble waste was characterized by different methods such as XRD, XRF, FTIR, particle size analysis and zeta potential. Calcite and dolomite minerals were the main constituents of this waste (91%). The average particle size was 6.656 µm. The fine fraction with a particle size of less than 25 µm contains 97.6% calcite with 81% weight. Sodium N-lauroyl sarcosinate (SNLS) was used as a selective flotation collector for calcite as a calcium mineral. A flotation concentrate with a purity of 99.6% and an overall yield of 80% was obtained at a pH of 9. The bleached product meets ASTM standard specifications for paint and paper applications.

Hydrolytic reactivity of novel copper(II) complexes with reduced N-salicylate threonine Schiff bases: distinguishable effects of various micelles

Three new bi- or tetranuclear copper (II) complexes (complexes 1, 2 and 3) with reduced N-salicylate threonine were synthesized and characterized by single crystal X-ray diffraction, X-ray powder diffraction, UV–vis, and thermogravimetric analysis. Single-crystal diffraction analysis reveals that these complexes have similar coordination modes and conformations which were linked into multidimensional networks through some weak interactions. These three complexes were employed to promote the hydrolytic cleavage of p-nitrophenyl picolinate (PNPP) and p-nitrophenyl acetate (PNPA). Catalytic reactivities of the as-prepared complexes show that in the hydrolysis of p-nitrophenyl acetate (PNPA) these three complexes provide 51, 45, 39-fold rate acceleration as compared to spontaneous hydrolysis of PNPA at pH 7.0, respectively. Under selected conditions, excess three orders of magnitude rate enhancement were observed for the catalytic hydrolysis of another carboxylic ester, p-nitrophenyl picolinate (PNPP). Furthermore, these complexes efficiently promote the PNPA hydrolysis in micellar solution of cetyltrimethylammonium bromide (CTAB) or bis(hexadecylhexmethyl ammonium)ethane bromide (16−6−16) giving rise to excess two orders of magnitude rate enhancement which is approximate 2.0 − 4.0 times higher than that in the buffer. However, the introduction of micelles of n-lauroylsarcosine sodium (LSS) or double-chained C22/8 surfactant did not increase the rate or even inhibited the hydrolysis reaction in contrast with buffered aqueous medium.

Influence of HSA on micellization of NLSS and BC: An experimental-theoretical approach of its binding characteristics

Blood albumins play a very significant role in several biological operations and act as carriers for the transportation and circulation of various endogenous as well as exogenous materials. Experimental as well as computational studies have been carried out in understanding the major binding properties of the system. This investigation explains the interactions of Human serum albumin (HSA) with N-Lauroyl sarcosine sodium salt (NLSS) and benzethonium chloride (BC), which has been explored by means of conductometric, spectroscopic as well as computational studies. Phenomenon of micellization is hindered in several concentrations of protein (HSA) as well as by temperature. Binding ability of HSA with NLSS and BC has been obtained through UV–visible and fluorescence studies. Computational study revealed the presence of seven binding pockets in HSA, out of which the most stable binding pockets for NLSS and BC includes pocket1 and pocket2.

Microstructure and permeability of porous zirconia ceramic foams prepared via direct foaming with mixed surfactants

The permeability performance of porous ceramics from particle-stabilized foams is closely associated with the connectivity between bubble-evolved pores. In order to regulate the connectivity of pore structure, the zirconia ceramic foams were fabricated by direct foaming with mixed surfactants of cetyltrimethyl ammonium bromide (CTAB) and sodium N-lauroyl sarcosinate (SLS). Different solid loadings and CTAB:SLS mixing ratios were used in this study. The results indicate that the pore structures of zirconia ceramic foams were interconnected by open windows on the cell walls, and the porosity and average size of cell and cell windows could be tailored by adjusting the solid loading and CTAB:SLS mixing ratio. The decrease in solid loading and CTAB:SLS mixing ratio caused larger porosity and size of cells and cell windows, and thus resulted in the obvious augment of Darcian (k1) and non-Darcian (k2) permeability constants. The ranges of k1 and k2 of the as-fabricated zirconia ceramic foams are 6.92 × 10−13-4.05 × 10−10m2 and 2.09 × 10−5-3.19 × 10−9m respectively.

Sodium N-Lauroylsarcosinate (SNLS) as a Selective Collector for Calcareous Phosphate Beneficiation

Sodium N-lauroylsarcosinate (SNLS) was employed as a selective flotation collector for dolomite–apatite separation. The influence of pH, condition time, and collector dose on the flotation performance of both apatite and dolomite minerals was investigated using single mineral and binary mixed mineral flotation experiments. The performance of SNLS was compared to sodium oleate (NaOL), as a standard collector. In this study, the adsorption mechanism of SNLS on both minerals was studied using zeta-potential and FT-IR measurements. The results showed that SNLS prefers to adsorb on the dolomite mineral. The maximum difference in floatability was 83% for single dolomite and apatite minerals at pH 10 in the presence of 0.05 mmol/L SNLS. Binary mixtures of dolomite and apatite minerals of different ratios were applied, to evaluate their separation efficiency. The SNLS could separate dolomite from its mixtures with apatite minerals. Using 0.2 mmol/L of SNLS at pH 10, a concentrate of 30.9% P2O5 and 0.79% MgO was obtained from a natural phosphate ore having 25.8% P2O5 and 5.16% MgO.

Study on the synthesis and performance of sodium 2-laurylamido isobutyrate

Abstract In the present work, sodium 2-laurylamido isobutyrate was synthesized from 2-aminoisobutyric acid, NaOH and lauroyl chloride by the Schotten-Baumann condensation. Fourier transform infrared spectroscopy, mass spectroscopy and nuclear magnetic resonance spectroscopy were used to characterize the products, and confirming the successful synthesis of sodium 2-laurylamido isobutyrate. The influence of temperature on the surface tension of sodium 2-laurylamido isobutyrate was studied, comparing the chemical properties of the surface with those of sodium N-lauroyl sarcosinate. The results indicate that both surfactants have a similar pC 20, while the critical micelle concentration (CMC) and the surface tension at the critical micelle concentration (γ CMC) of sodium 2-laurylamido isobutyrate are higher than those of sodium N-lauroyl sarcosinate. Further studies on the thermodynamic parameters of sodium 2-laurylamido isobutyrate and sodium N-lauroyl sarcosinate indicate that the formation of micelles is a spontaneous exothermic process mainly driven by entropy. According to the dynamic surface tension of sodium 2-laurylamido isobutyrate and sodium N-lauroyl sarcosinate, the molecular adsorption of the two components mixture change from the initial diffusion controlled adsorption to the later mixed dynamic controlled adsorption.

Optimizing detection of erythropoietin receptor agonists from dried blood spots for anti-doping application.

The World Anti‐Doping Agency (WADA) has recently implemented dried blood spots (DBSs) as a matrix for doping control. However, specifications regarding the analysis of the class of prohibited substances called erythropoietin (EPO) receptor agonists (ERAs) from DBSs are not yet described. The aim of this study was to find optimal conditions (sample volume and storage) to sensitively detect endogenous erythropoietin (hEPO) and prohibited ERAs from DBSs and compare detection limits to WADA‐stipulated minimum required performance levels (MRPLs) for ERAs in serum/plasma samples. Venous whole blood was spotted onto Whatman 903 DBS cards with primarily 60 μl of blood, but various volumes from 20 to75 μl were tested. All samples were immunopurified with MAIIA EPO Purification Gel kit (EPGK) and analysed with sodium N‐lauroylsarcosinate polyacrylamide gel electrophoresis (SAR‐PAGE) and Western blot. Sixty‐microliter DBSs allowed the detection of the four main ERAs (BRP, NESP, CERA and EPO‐Fc) at concentrations close to WADA's MRPLs described for 500 μl of serum/plasma. Different storage temperatures, from −20°C to 37°C, were evaluated and did not affect ERA detection. A comparison of the detection of endogenous EPO from the different anti‐doping matrices (urine, serum and DBSs produced from upper arm capillary blood) from five participants for 6 weeks was performed. Endogenous EPO extracted from DBSs showed intra‐individual variations in male and female subjects, but less than in urine. Doping controls would benefit from the stability of ERAs on DBSs: It can be a complementary matrix for ERA analysis, particularly in the absence of EPO signals in urine.

Ion flotation of heavy metal ions by using biodegradable biosurfactant as collector: Application and removal mechanism

• By using the biosurfactant LS, ion flotation can be used to remove heavy metal ions . • The ability of LS to remove heavy metal ions is better than that of SDS . • The high flotation removal performance of LS is due to its structural advantages. • The carboxyl group and amide of LS react with metal ions. • LS reacts with Pb(II) and generates a four-membered ring complex. Ion flotation was used to remove copper(II), lead(II) and chromium(III) from simulated wastewater using a new biodegradable biosurfactants, namely, sodium N-lauroylsarcosinate (LS), and the synthetic surfactant sodium dodecyl sulfate (SDS) as collectors. The use of LS resulted in better removal of metal ions than that achieved with SDS. It was found that the removal efficiency of single metal ions can reach more than 95%. The results showed that the complex formed by surfactant and metal ion was flocculent and loose in structure, which may be the main reason for the slow ion flotation speed. XPS and IR analysis showed that there was a complex reaction between the sulfonic group of SDS and the carboxyl group of LS with metal ions. These findings indicate that the new biosurfactant LS has a better treatment effect on wastewater containing heavy metal ions and compared with industrial surfactants (such as SDS), LS is degradable and environmentally friendly, potentially leading to better industrial application. DFT theory further confirmed the experimental results. The calculated results show that LS has higher complexation ability for Pb(II) than dose SDS. LS reacts with Pb to form a four-membered ring complex containing two O atoms, which has higher stability than the complex containing SDS.

Introduction of a PEGylated EPO conjugate as internal standard for EPO analysis in doping controls.

Immunopurification of doping control samples is a mandatory necessity in erythropoietin (EPO) analysis during a confirmation procedure; moreover, it has become common practice to also immunopurify samples for the initial testing procedure. Typically used materials (e.g., Stemcell purification plate and MAIIA purification kit) rely on anti-EPO antibodies for purification. Also, the detection of EPO after electrophoretic separation and western blotting is based on a monoclonal anti-EPO antibody, clone AE7A5, directed against a 26 amino acid sequence of the N-terminal region of human EPO. While the electrophoretic separation and blot transfer efficiency can be monitored with reference standards and quality control samples, it is presently not possible to monitor the functionality of the entire sample preparation procedure. The reliance on antibodies for both purification and detection has complicated the implementation of an internal standard (ISTD). In this study, customized EPO-polyethylene glycol (PEG) conjugates were synthesized as potential ISTDs and assessed as to their compatibility with existing sample preparation procedures for urine and blood sample analysis using the most common immunopurification techniques. Moreover, probing for the impact of the ISTD on sodium N-lauroylsarcosinate ("sarcosyl") polyacrylamide gel electrophoresis (SAR-PAGE)-based EPO analysis concerning potential interference with target analytes was conducted. The presented data demonstrate that a 12-kDa PEG residue attached to human EPO represents a particularly useful construct to serve as ISTD for erythropoietin-receptor agonist (ERA) analysis. The conjugate is applicable to both urine and blood testing using the commonly employed purification techniques, supporting and improving result interpretations especially concerning specimens where the natural abundance of human EPO is low.

Formation and characterization of microemulsion with novel anionic sodium N-lauroylsarcosinate for personal care

Microemulsions are unique clear systems comprising of oil, water, surfactant and cosurfactants that offered stimulating perspectives in various applications. The purpose of these study was to create a microemulsion using novel amino acid based anionic sodium N-lauroylsarcosinate (SNLS) surfactant for application in personal care formulations. Triglyceride oils such as caprylic acid, oleic acid and carboxylic acid ester isoamyl acetate were used as oil phase, while short chain alcohols like propanol and butanol were used as cosurfactants. The gradual variations happening in the microstructure of the microemulsions were explored via several complementary characterization techniques. Phase diagrams constructed with or without cosurfactants and using different ratio of surfactant/ cosurfactant (Smix) showed that largest microemulsion region was observed only in the presence of cosurfactant and from Smix of 1:1. Solubility of SNLS in pure water is around 30 wt%, which upsurges in presence of propanol or butanol up to around 85 wt%. This leads to increase in microemulsion region in phase diagram with increasing solubility of oils in the SNLS solution. Microemulsions were relatively stable at an ambient temperature of 27 °C. The optical microscopy, electrical conductivity and viscosity measurement were performed to examine the microstructural changes within the microemulsion region. Three different phases such as water in oil (w/o), bicontinuous, and oil in water (o/w) microemulsion were observed. Foaming behavior specifies increased foam stability of SNLS in the presence of certain amount of oils. Dynamic light scattering study supports the well-defined microemulsion stability even after the manifold dilution. The results obtained from this study may have implications for the developments of an appropriate tactic to prepare stable microemulsion from SNLS which could be exceedingly favorable for personal care formulations.

The inhibitory effects of toothpaste and mouthwash ingredients on the interaction between the SARS-CoV-2 spike protein and ACE2, and the protease activity of TMPRSS2 in vitro.

SARS-CoV-2 enters host cells when the viral spike protein is cleaved by transmembrane protease serine 2 (TMPRSS2) after binding to the host angiotensin-converting enzyme 2 (ACE2). Since ACE2 and TMPRSS2 are expressed in the tongue and gingival mucosa, the oral cavity is a potential entry point for SARS-CoV-2. This study evaluated the inhibitory effects of general ingredients of toothpastes and mouthwashes on the spike protein-ACE2 interaction and the TMPRSS2 protease activity using an in vitro assay. Both assays detected inhibitory effects of sodium tetradecene sulfonate, sodium N-lauroyl-N-methyltaurate, sodium N-lauroylsarcosinate, sodium dodecyl sulfate, and copper gluconate. Molecular docking simulations suggested that these ingredients could bind to inhibitor-binding site of ACE2. Furthermore, tranexamic acid exerted inhibitory effects on TMPRSS2 protease activity. Our findings suggest that these toothpaste and mouthwash ingredients could help prevent SARS-CoV-2 infection.

Effect of sodium N-lauroylsarcosinate/hypromellose on the dispersibility and rheological behavior of carbon black for paper coating application

The dispersibility of the carbon black (CB) in aqueous phase is rather critical for its application in paper coatings. In the present work, sodium N-lauroylsarcosinate/hypromellose (HPMC) was developed/prepared via hydrated reaction, which was subsequently used as a dispersant for improving the dispersibility of CB dispersion. The effects of the as-prepared dispersant on the dispersibility and rheological behavior of the CB dispersion were systematically studied, and the microstructure and properties of the CB dispersion were comprehensively characterized. The results showed that the presence of dispersant could reduce the viscosity and enhance the zeta potential of the CB dispersion. Compared with the CB dispersion without dispersant, the viscosity of CB dispersion with 4.0 wt% dispersant was decreased by 7.3%, and the zeta potential was increased by 167%. The average particle size and adsorption capacity of CB dispersion with 4.0 wt% dispersant retained 190 nm and 3351 mg/g, respectively. With the increase of dispersant amount, the dynamic viscoelasticity was gradually increased. It was further inferred that sodium N-lauroylsarcosinate part increased the electrostatic repulsion between CB particles, and the HPMC part particularly enhanced the steric hindrance. These two parts could produce a positive synergistic dispersion effect and made the CB dispersion more stable.

A novel detergent-based decellularization combined with carbodiimide crosslinking for improving anti-calcification of bioprosthetic heart valve

Currently, valve replacement surgery is the only therapy for the end-stage valvular diseases because of the inability of regeneration for diseased heart valves. Bioprosthetic heart valves (BHVs), which are mainly derived from glutaraldehyde (GA) crosslinked porcine aortic heart valves or bovine pericardium, have been widely used in the last decades. However, it is inevitable that calcification and deterioration may occur within 10–15 years, which are still the main challenges for the BHVs in clinic. In this study, N-Lauroylsarcosine sodium salt (SLS) combined with N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) were utilized to decellularize and crosslink the heart valves instead of GA treatment. The obtained BHVs exhibited excellent extracellular matrix stability and mechanical properties, which were similar with GA treatment. Moreover, the obtained BHVs exhibited better in vitro biocompatibilities than GA treatment. After subcutaneous implantation for 30 d, the obtained BHVs showed mitigated immune response and reduced calcification compare with GA treatment. Therefore, all the above results indicated that the treatment of SLS-based decellularization combined with EDC/NHS crosslink should be a promising method to fabricate BHVs which can be used in clinic in future.

Experimental investigation on combined modification for micro physicochemical characteristics of coal by compound reagents and liquid nitrogen freeze-thaw cycle

To meet urgent demands for efficient resources and sustainable development, an experimental study on combined physicochemical modification of coal was carried out. After 49 tests analyzed of single-factor experiment and orthogonal experiment, it was found that MW (mine water), 6% SLS (sodium N-lauroyl sarcosinate), 10% HNO3 and 3% [Bmim]Cl (1-Butyl-3-methylimidazole chloride), freeze-thaw cycle 8 times, and freeze-thaw time of 1.25 h each time was the best physicochemical modification scheme. Compared with raw coal, the wettability, porosity and permeability of the treated coal are significantly increased. Under the synergy of the combined physicochemical modification (including hydrogen bonding and tight filling) and the multi-field coupling (including temperature field, stress field and deformation field), the porosity is at an increase rate of 335.65%; the permeability is at an increase rate of 882.24%; while surface tension of the compound reagent is reduced to 16.24 mN/m. Furthermore, the relative content of C–C bonds and C–H bonds on coal surface increases greatly, while the relative content of C-O and COO decreased gradually, with a decrease rate of 57.61%. The results of this paper are beneficial to achieve efficient co-mining of coal and coalbed methane, and further improve safety and efficient production levels of coal mines.

A facile and controllable one-pot synthesis approach to amino-functionalized hollow silica nanoparticles with accessible ordered mesoporous shells

The development of a practical synthetic method to functionalize hollow mesoporous silica with organic groups is of current interest for selective adsorption and energy storage applications. Herein, a facile and controllable one-pot approach for the synthesis of monodisperse amino-functionalized hollow mesoporous silica nanoparticles is presented. A novel solid-to-hollow structural transformation procedure of the silica nanoparticles is presented. The structural transformation is easily designed, as observed through transmission electron microscopy, by tailoring the HCl and N-lauroylsarcosine sodium molar ratio and the water content in the sol-gel. Ordered and radially oriented in situ amino-functionalized mesochannels were successfully introduced into the shells of the hollow silica nanoparticles. A formation mechanism for the hollow mesoporous silica materials is discussed.

New role of the conventional foamer sodium N-lauroylsarcosinate as a selective collector for the separation of calcium minerals

Fluorite and scheelite are strategic calcium minerals and usually separated through froth flotation. However, the selective separation of fluorite and scheelite remains a great challenge because of their similar physiochemical surface properties. As a green, stable and low-cost surfactant with good biodegradability and foamability, sodium N-lauroylsarcosinate (SNLS) has been widely applied in cosmetics, biological medicine, electroplating and other fields. In this study, SNLS was used as a novel collector for the separation of fluorite from scheelite without any depressant. The flotation tests of binary mixed minerals showed that the selectivity of SNLS for fluorite was higher than that for scheelite at pH 9.0 and a low dosage of 1.1 × 10−5 mol/L. Zeta potential results revealed that SNLS was negatively charged at pH 9.0 and adsorbed on positively charged fluorite surfaces through electrostatic interactions. The results of Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and Density functional theory (DFT) calculations indicated that the chemical adsorption of the three active O atoms of SNLS on fluorite was stronger than that on scheelite. These O atoms could form a Ca–NLS complex because of the greater Ca density and the higher Ca reactivity on fluorite than on scheelite. Therefore, SNLS has great potential for industrial application in the separation of fluorite from scheelite.

Catanionic mixtures of surface-active ionic liquids and N-lauroyl sarcosinate: Surface adsorption, aggregation behavior and microbial toxicity

The surface activity and aggregation behavior of catanionic mixtures of imidazolium- or pyridinium-based surface-active ionic liquids (SAILs) and sodium N-lauroyl sarcosinate (Na-LS) in aqueous solution were investigated. The effects of the alkyl chain length, the polar head group and functional groups in the SAIL molecule on the interfacial properties and self-assembly of the catanionic mixtures were evaluated by surface tension and dynamic light scattering measurements. In addition, the toxicity of the catanionic surfactant mixtures against bacteria and fungi was studied. The SAIL-LS mixed systems reduced water surface tension with high effectiveness and efficiency, and had a lower critical aggregation concentration compared to the individual components. In all the catanionic systems investigated, synergistic effects caused by strong electrostatic and hydrophobic interactions resulted in negative interaction parameter values, which increased with the alkyl chain length and in the order of non-functionalized < amide-functionalized < ester-functionalized SAILs. The structure of the mixed aggregates in the SAIL-LS catanionic systems depended on the hydrophobicity of the SAIL, the micelle-vesicle transition being driven by the alkyl chain length. The catanionic systems exhibited similar microbial toxicity to that of individual SAIL components and behaved like broad-spectrum antimicrobials.

Integration of PEGylated Polyaniline Nanocoatings with Multiple Plastic Substrates Generates Comparable Antifouling Performance.

Conducting polymer nanocoatings render plastics to possess interesting optical, chemical, and electrical properties. It nevertheless remains technically challenging to deposit uniform conducting polymer nanocoatings on ambient plastic substrates ascribed to the inert and varied chemical properties of plastics and the notorious processability of conducting polymers. Previous studies have made progress in delivering various conducting polymer thin films via oxidative chemical vapor deposition. Herein, we develop a solution-based approach to polyaniline (PANI) and PEGylated PANI nanocoatings on multiple engineering plastics followed by evaluating their antifouling performance. The procedure relies on the formation of uniform, lyotropic V2O5·nH2O thin films on plastics assisted by a surfactant-sodium N-lauroylsarcosinate. Next, in situ, oxidative polymerization causes the formation of nanofibrous PANI nanocoatings. Finally, interfacial functionalization leads to PEGylated PANI nanocoatings, and the steric nanolayer effectively repels the adsorption of bovine serum albumin and the attachment of the bacterium Pseudoalteromonas sp. on the surface. It is worth noting that the antifouling properties rely mainly on the presence of PEGylated PANI nanocoatings, irrespective of the type of plastic substrates underneath. The current study therefore opens an avenue for the solution-based delivery of conducting polymer-based, functional nanocoatings on hydrophobic substrates in a controllable manner with the availability of further modification.

Experimental study on modification of physicochemical characteristics of acidified coal by surfactants and ionic liquids

To study the modification of the physicochemical characteristics of acidified coal by surfactants and ionic liquids, N2 adsorption, scanning electron microscopy and so on, combined with fractal theory were used. The results show that when the coal sample is treated with HNO3, a large number of corrosion pores can be generated, and the aromaticity of the coal can be improved. [Bmim]Cl (1-Butyl-3-methylimidazolium chloride) can reduce the proportion of oxygen-containing functional groups. Both HNO3 and [Bmim]Cl can effectively reduce the mineral content of coal. Neither HNO3 nor [Bmim]Cl is conducive to the wettability of coal, they increase the surface tension by 10.79 mN/m and 2.66 mN/m, respectively; SLS (Sodium N-lauroyl sarcosinate) reduces it by 20.79 mN/m. So SLS is added to improve the wettability. The combined action of HNO3 and SLS not only decreases the surface tension to 22.16 mN/m, which is 39.16% of that of HNO3 and can improve the wettability of the coal; but also, greatly increase the injectable water porosity of coal to 9.28%, which is 2.15 times of that of coal sample #1 and beneficial to coal seam water injection. HNO3, SLS and [Bmim]Cl have a strong synergistic effect, which severely breaks the pore size distribution of coal but can enlarge the average pore size of the coal and increase the porosity by 1.58 times. This approach can provide a new way to improve the efficiency of coalbed methane mining.

Micellar electrokinetic capillary chromatographic determination of pirfenidone and 5-carboxy-pirfenidone by direct injection of plasma from patients receiving treatment for idiopathic pulmonary fibrosis (IPF)

A micellar electrokinetic capillary chromatographic method, a variant of capillary electrophoresis, was developed for the detection and measurement of pirfenidone and 5-carboxy-pirfenidone by direct injection of plasma from patients under treatment for idiopathic pulmonary fibrosis. To achieve the best separation a 35 mmol/L N-lauroylsarcosine sodium salt surfactant added with a 16 mmol/L sodium 1-heptanesulfonate solution was used as a running buffer. Analytes were eluted in a fairly short time, 7.35 and 9.40 min for pirfenidone and 5-carboxy-pirfenidone, respectively, at 15 °C and with an applied voltage of 30 kV in an 80 cm, 75 µm i.d. uncoated fused-silica capillary. In the range of 6.25–200 µmol/L, calibration curves exhibited acceptable linearity with the coefficient of determination higher than 0.999. The recovery of analytes spiked in samples of plasma was found to be 95–109% and 93–106% for pirfenidone and 5-carboxy-pirfenidone, respectively. Intra- and inter-day precisions were around 5%. LOD and LOQ for pirfenidone and 5-carboxy-pirfenidone were, respectively, 1.0 and 4.0 µmol/L. The method, applied to measure analytes in six idiopathic pulmonary fibrosis male patients, provided mean concentrations of 68.91 ± 26.31 and 36.21 ± 26.39 µmol/L for pirfenidone and 5-carboxy-pirfenidone, respectively.