Methyl Butyl Research Articles

Physical-Chemical Properties and Engine Performance of Blends of Biofuels with Gasoline

Addition of 10 vol% biomass-based methyl levulinate (ML), ethyl levulinate (EL), butyl levulinate (BL), gamma-valerolactone (GVL), dimethyl carbonate (DimC), and diethyl carbonate (DieC) in gasoline were selected as blended fuels. Physical-chemical properties of six different blends of biofuels and gasoline, including miscibility, octane number, distillation, vapor pressure, unwashed gum content, solvent washed gum content, copper corrosiveness, water content, mechanical admixtures, and lower heating value was evaluated according to the China National Standards. Blended fuels were then evaluated on the performance and emissions of a gasoline test engine without any modification. The results showed that all biomass-based fuels at 10 vol% have good miscibility in gasoline at temperatures of –30 to 30 °C. Experiments were performed at 4500 rpm engine speed at different engine loads (from 10% to 100% in 10% intervals). Results showed slightly lower engine power at different loads with the blended fuels than those from gasoline fuelled engine. However, the brake specific fuel consumption (BSFC) with the blended fuels was slightly higher than that from gasoline. Emission of carbon monoxide (CO), total unburned hydrocarbon (THC) and oxides of nitrogen (NOx) was reduced significantly from the blended fuels compared to gasoline while carbon dioxide (CO2) emission was slightly higher than that from gasoline. The data suggests that 10 vol% addition of biomass-based levulinates and carbonates fuels to gasoline is suitable for use in gasoline engines.

Water-Resistant Latex Coatings: Tuning of Properties by Polymerizable Surfactant, Covalent Crosslinking and Nanostructured ZnO Additive

This paper deals with the development of acrylic latexes providing high-performance water-resistant coatings. For this purpose, mutual effects of anionic surfactant type (ordinary and polymerizable), covalent intra- and/or interparticle crosslinking (introduced by allyl methacrylate copolymerization and keto-hydrazide reaction, respectively) and ionic crosslinking (provided by nanostructured ZnO additive) were investigated. The latexes were prepared by the standard emulsion polymerization of methyl methacrylate, butyl acrylate and methacrylic acid as the main monomers. The addition of surface-untreated powdered nanostructured ZnO was performed during latex synthesis, resulting in stable latexes comprising dispersed nanosized additive in the content of ca 0.9−1.0 wt.% (based on solids). The coating performance with emphasis on water resistance was evaluated. It was determined that the application of the polymerizable surfactant improved coating adhesion and water-resistance, but it wasn′t able to ensure high water-resistance of coatings. Highly water-resistant coatings were obtained provided that covalent intra- and interparticle crosslinking together with ionic crosslinking were employed in the coating composition, forming densely crosslinked latex films. Moreover, coatings comprising nanostructured ZnO additive displayed a significant antibacterial activity and improved solvent resistance.

Synthesis and characterization of some new thiazolidinone derivatives containing indole ring

Many new heterocyclic compounds including 4-thiazolidinones containing indole with triazole units were described. The new Schiff bases [VII]a, b and [VIII]a,b synthesized by condensation acid hydrazides [II],[VI] with different (aromatic) aldehydes in absolute ethanol. The refluxing equimolar amounts of the Schiff bases ([VII]a,b, [VIII]a,b) with thioglycolic acid in benzene led to get thiazolidin-4-ones derivatives ([IX]a,b and [X]a-d). Finally, the new derivatives [XI]a-c run out via the reacted compound [IX]a with different n-alkyl bromide (methyl bromide, ethyl bromide, and butyl bromide) in alkaline media.

Synthesis and Biological Activity of Acrylate Copolymers Containing 3-Oxo-N-allyl-1,2-benzisothiazole-3(2H)-carboxamide Monomer as a Marine Antifouling Coating.

A type of grafted acrylate copolymer resins, containing 3‐oxo‐N‐allyl‐1,2‐benzisothiazole‐2(3H)‐carboxamide monomer and heterocyclic monomers, was synthesized through the copolymeri‐ zation of methyl methacrylate (MMA) and butyl acrylate (BA) with functional monomers. The structures of the monomers and copolymers were validated by infrared (IR) and 1H nuclear magnetic resonance (NMR) spectroscopies. The inhibitory activities of the copolymers on algae, bacteria, and barnacle larvae were measured, and the antifouling potencies against marine macrofouling organisms were investigated. The results showed that the grafted resin had significant inhibitory effects on the growth of three marine algae (Isochrysis galbana, Nannochloropsisoculata, and Chlorella pyrenoidosa), and three bacteria (Vibrio coralliilyticus, Staphylococcus aureus,and Vibrio parahaemolyticus). The target copolymers also showed excellent inhibition of the survival of barnacle larvae. Additionally, the release rate of the antifoulant and the results of the marine field tests indicated that the grafted copolymers had outstanding antifouling potency against the attachment of marine macrofouling organisms.

Thermochemical study of anthranilate derivatives: Effect of the size of the alkyl substituent

The gas-phase enthalpies of formation of two fragrance compounds, methyl anthranilate and butyl anthranilate, at T = 298.15 K, were determined from the combination of the corresponding enthalpies of vaporisation and energies of combustion, obtained from Calvet microcalorimetry and combustion calorimetry measurements, respectively. Additionally, theoretical calculations were performed, using the G3(MP2)//B3LYP composite method, to estimate the gas-phase enthalpies of formation of the two fragrance compounds. The good agreement between the experimental and computational gas-phase enthalpies of formation of the methyl anthranilate and butyl anthranilate, provided the confidence for extending the theoretical study to propyl anthranilate. Furthermore, the results were interpreted in terms of enthalpic increments, aiming to evaluate and understand the energetic effect inherent to the alkyl group (methyl, ethyl, propyl or butyl) present in the ester functional group of the anthranilate derivatives.

Exposure to parabens and associations with oxidative stress in adults from South China

Parabens are widely applied as preservatives in cosmetics, drugs and food. Previous studies suggested that parabens could exhibit potential risks to human health. However, data on human exposure levels and health effects of parabens remain limited, especially in the potential effects on DNA oxidative stress. This study aimed to investigate urinary levels of parabens in adults from South China and explore the relationships between urinary parabens and DNA oxidative stress. Five short chain parabens, including methyl paraben (MeP), ethyl paraben (EtP), n-propyl paraben (PrP), butyl paraben (BuP) and benzyl paraben (BzP), were determined in urine from 319 adults in Shenzhen, China. MeP, EtP and PrP were frequently detected in urine samples (detection frequencies >66.5%), suggesting broad exposure in South China adults. Median concentrations of MeP, EtP, PrP, BuP and BzP were 5.78, 0.39, 0.35, 0.01 and 0.02 μg/L, respectively. A significantly positive correlation was observed between the urinary concentrations of MeP and PrP (p < 0.01), suggesting similar sources for these two chemicals. In addition, participants with alcohol consumption exhibited significantly lower paraben concentrations in urine than those without alcohol drinking (p < 0.05). Significant association was observed between urinary concentrations of parabens and 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels (p < 0.01), while no significant dose-response relationship was found (p > 0.05). A potential risk from PrP exposure was found in South China adults.

Actinomycetes isolates of arid zone of Indian Thar Desert and efficacy of their bioactive compounds against human pathogenic bacteria.

Twenty-six morphotypes of actinomycetes bacteria were isolated from the soils of arid zone of Indian Thar desert, Rajasthan. A significant and positive correlation was found between density of actinomycetes isolates and availability of nitrogen in sandy soil of arid zone suggesting the influence of soil nitrogen on occurrence and propagation of actinomycetes in this region. Molecular identification based on 16S rRNA gene sequencing revealed that the bacterial isolates belong to four actinomycetes genera, viz. Streptomyces (22 species), Nocardiopsis (two species), Saccharomonospora (one species) and Actinoalloteichus (one species). The preliminary screening of 26 isolates against five human pathogenic bacteria, viz. Escherichia coli, Vibrio cholera, Salmonella enterica typhimurium, Staphylococcus aureus and Enterococcus faecalis, showed that only four isolates, viz. Streptomyces sp. (ITD-27), S. enissocaesilis (ITD-29), S. Malachitospinus (ITD-35) and Streptomyces sp. (ITD-47), had antibacterial activity. The secondary screening of these four isolates revealed that the isolate S. malachitospinus (ITD-35) showed the maximum growth inhibition zone and inhibited the growth of all tested gram-positive and gram-negative pathogenic bacteria. Gas chromatography-mass spectrometry analysis of S. malachitospinus (ITD-35) cultural filtrate in n-butanol solvent identified three antibacterial compounds of medicinal significance, viz. 3-octanone, neopentyl isothiocyanate and 2-methyl butyl isothiocyanate.

Application of grouping and read-across for the evaluation of parabens of different chain lengths with a particular focus on endocrine properties

This article presents the outcomes of higher-tier repeated-dose toxicity studies and developmental and reproductive toxicity (DART) studies using Wistar rats requested for methyl paraben and propyl paraben under the European Union chemicals legislation. All studies revealed no-observed adverse effects (NOAELs) at 1000 mg/kg body weight/day. These findings (absence of effects) were then used to interpolate the hazard profile for ethyl paraben, further considering available data for butyl paraben. The underlying read-across hypothesis (all shorter-chained linear n-alkyl parabens are a ‘category’ based on very high structural similarity and are transformed to a common compound) was confirmed by similarity calculations and comparative in vivo toxicokinetics screening studies for methyl paraben, ethyl paraben, propyl paraben and butyl paraben. All four parabens were rapidly taken up systemically following oral gavage administration to rats, metabolised to p-hydroxybenzoic acid, and rapidly eliminated (parabens within one hour; p-hydroxybenzoic acid within 4–8 h). Accordingly, for ethyl paraben, the NOAELs for repeated-dose toxicity and DART were interpolated to be 1000 mg/kg body weight/day. Finally, all evidence was evaluated to address concerns expressed in the literature that parabens might be endocrine disruptors. This evaluation showed that the higher-tier studies do not provide any indication for any endocrine disrupting property. This is the first time that a comprehensive dataset from higher-tier in vivo studies following internationally agreed test protocols has become available for shorter-chained linear n-alkyl parabens. Consistently, the dataset shows that these parabens are devoid of repeated-dose toxicity and do not possess any DART or endocrine disrupting properties.

Effect of shell phase composition on the dielectric property and energy density of core‐shell structured BaTiO3 particles modified poly(vinylidene fluoride) nanocomposites

AbstractDielectric nanocomposites have attracted much attention due to their wide applications in electronics and electrical industry. Recently, incorporating core‐shell nanoparticles into polymer matrix to improve the dielectric properties of nanocomposites has been widely reported. Tailoring the interfacial region between the polymer and the nanoparticles plays a crucial role in achieving the desired dielectric and energy storage properties of nanocomposites. However, the effect of shell structure in the interface region on the dielectric and energy storage properties is rarely studied. Based on this, core‐shell BaTiO3 nanoparticles with two different shell polymers, a “hard‐soft” copolymer of methyl methacrylate and butyl acrylate (P[MMA‐BA]) and a “hard” homopolymer of methyl methacrylate (PMMA), were prepared in this paper. The effect of core‐shell BaTiO3 nanoparticles with different shell structures on the dielectric and energy storage properties of poly(vinylidene fluoride) (PVDF) was investigated in depth. Due to the formation of a tight interfacial region between P(MMA‐BA)@BT and PVDF matrix, P(MMA‐BA)@BT/PVDF nanocomposites not only have low dielectric loss but also higher energy efficiency than PMMA@BT/PVDF nanocomposites. This study suggests a potential strategy that fabricating a “hard‐soft” copolymer shell on BaTiO3 surface can obtain desirable energy storage efficiency than the single “hard” shell structure in dielectric nanocomposites.

Preparation of hydrophobic macroinimer-based novel hybrid sorbents for efficient removal of organic liquids from wastewater.

Herein, the synthesis of hydrophobic macroinimer-based hybrid sorbents and their use in the removal of organic solvents from wastewater is explored. Polydimethylsiloxane (PDMS), 4,-4'-azobis-4-cyanopentanoyl chloride (ACPC), and methacryloyl chloride were reacted via bulk condensation polymerization to synthesize the macroinimer. The organogel systems were then prepared with macroinimer using different acrylic monomers of methyl acrylate, ethyl acrylate, and butyl acrylate without any additional crosslinker and initiator. The structural properties of the obtained final products were characterized by FT-IR, 1H-NMR, and TGA. The effect of alkyl chain length and macroinimer moieties in the organogel networks, as well as the swelling capacities of the prepared gels, was evaluated for different organic solvents and oils. The maximum solvent absorbencies of macroinimer-based organogels were determined as 85.3%, 100.9%, 1422.1%, 1660.0%, 3809.3%, and 5032.2% for diesel oil, gasoline, acetone, benzene, tetrahydrofuran (THF), and dichloromethane (DCM), respectively. Furthermore, adsorption-desorption kinetics, selective absorption from oil/water mixtures, temperature effect on the absorption capacity, and reusability tests were investigated. Obtained results showed that the prepared organogels possessed high swelling, efficient absorption capacity, and good oil separation performance in the removal of organic solvents from wastewater. The temperature-dependent absorption study shows no significant change in absorption capacity. Thus, the prepared macroinimer-based organogels in the present study demonstrate potential as prospective sorbents for organic pollutant cleanup from wastewater.

LIQUID CHROMATOGRAPHY–MASS SPECTROMETRY/MASS SPECTROMETRY METHOD FOR THE DETERMINATION OF LAPATINIB IN RAT PLASMA: APPLICATION TO PHARMACOKINETIC STUDIES IN WISTAR RATS

Objective: The objective of the study was to develop and validate a simple, accurate, and sensitive liquid chromatography–mass spectrometry (LC–MS)/MS method for the determination of lapatinib a dual tyrosine kinase inhibitor in rat plasma using gefitinib as internal standard.&#x0D; Methods: An Inertsil ODS column (50 mm×4.6 mm×5 μm) was used for separation with isocratic elution of 10 mM ammonium formate-acetonitrile (5:95 v/v). Analyte and internal standard were extracted from 50 μl of plasma using tertiary butyl methyl ether followed by subsequent reconstitution in a mixture of water-acetonitrile.&#x0D; Results: The extraction recoveries were 95% and 98% for lapatinib and gefitinib, respectively. The lower limit of quantification was 5 ng/ml with a precision of 6.2% and accuracy of 108%. The response was found to be linear over the range of 5–1000 ng/ml with a correlation coefficient of 0.999. The intraday and interday precision expressed as relative standard deviation was &lt;15%.&#x0D; Conclusion: This validated method was applied to the pharmacokinetic study in Wistar rats. The proposed bioanalytical LC–MS/MS method for lapatinib is a simple, sensitive, and accurate to quantify the concentrations in rat plasma.

Synergistic effect of copolymeric resin grafted 1,2-benzisothiazol-3(2H)-one and heterocyclic groups as a marine antifouling coating.

In order to find a new type of antifouling coating with higher biological activity and more environmental protection, heterocyclic compounds and benzisothiazolinone were introduced into acrylic resin to prepare a new type of antifouling resin. In this study, a series of grafted acrylic resins simultaneously containing benzoisothiazolinone and heterocyclic monomers were prepared by the copolymerization of an allyl monomer with methyl methacrylate (MMA) and butyl acrylate (BA). Inhibitory activities of the copolymers against marine fouling organisms were also investigated. Results revealed that the copolymers exhibit a clear synergistic inhibitory effect on the growth of three seaweeds: Chlorella, Isochrysis galbana and Chaetoceros curvisetus, respectively, and three bacteria, Staphylococcus aureus, Vibrio coralliilyticus and Vibrio parahaemolyticus, respectively. In addition, the copolymers exhibited excellent inhibition against barnacle larvae. Marine field tests indicated that the resins exhibit outstanding antifouling potency against marine fouling organisms. Moreover, the introduction of the heterocyclic group led to the significantly enhanced antifouling activities of the resins; the addition of the heterocyclic unit in copolymers led to better inhibition than that observed in the case of the resin copolymerized with only the benzoisothiazolinone active monomer.

Assembling a Bunch of Transition Metals Oxides on Sodium Montmorillonite Layer for Anionic Polymerization of Butyl Methyl Acrylate

In the present study, Anionic polymerization of Butyl Methyl acrylate has been carried out in oxygen atmosphere over different heterogenic prepared catalytic systems which is composed of a group of three metal oxides ( Ti, Mn Cu ) assembled on thin layers of clay ( Bentonite ) as hydrogenating/dehydrogenating activation for the polymerization reaction. The prepared catalysts and polymeric products were distinguished by different spectroscopic techniques such as XRD , 1HNMR, ,energy-dispersive X-ray spectroscopy (EDX), SCN TEM, IR, and gel permeation chromatography(GPC). we deduced that the dimensions of the efficiency of each catalyst as well as whole composites on the polymerization of Butyl Methyl acrylate of process, also, we approach the reaction mechanism of the polymeric process, furthermore, studying the variation and factors affecting on anionic polymerization like polydispersity index and tactility properties, we approached more details and discussion were deeply investigated in blow throughout figures and applicable data analysis.

Antioxidant effects of gallic acid alkyl esters of various chain lengths in oyster during frying process

SummaryThe antioxidant effects of gallic acid (GA) and its alkyl esters including methyl gallate, ethyl gallate, propyl gallate, butyl gallate (GA‐C4), octyl gallate, lauryl gallate, hexadecyl gallate and octadecyl gallate in frying oil (soybean oil) and oyster during frying were investigated. Rancimat induction period (RIP) assay indicated GA and its alkyl esters effectively improved the oxidative stability of soybean oil according to the ‘polar paradox’; that is, the antioxidant effects of the polyphenols decreased in lipid system with the increasing of hydrophobicity. Results also indicated that GA and its alkyl esters all effectively retarded lipid oxidation in oyster tissue according to parameters including RIP, peroxide value and electron spin resonance assays. Moreover, the antioxidant efficiency in oyster increased with the alkyl chain length until GA‐C4, and thereafter, the antioxidant effects decreased, similar to the ‘cut‐off effect’. This study provides basic data for improving the oxidative stability of seafood during frying.

Quantitative Stability Indicating Bio-analytical Method Development and Validation of Apalutamide - Apalutamide D3 By Using Ultra Performance Liquid Chromatography in Human Plasma

A simple, convenient, specific, precise and highly conventional stability-indicating ultra-performance liquid chromatographic‑ diode array method was developed for the quantification of Apalutamide in human plasma. The Phenomenex Luna (100x4.6x5µ) column was used for apalutamide separation. The mobile phase was composed with 5 mM ammonium fumarate and acetonitrile in the ratio of 15:85 v/v, and buffer pH 3.5 was adjusted with glacial acetic acid and detected at 345 nm. The Apalutamide‑D3 used as internal standard and K2‑EDTA used as a coagulant. The liquid-liquid extraction process used for extraction of drug from human plasma with tert butyl methyl ether. The retention times of Apalutamide and Apalutamide D3 (ISTD) was 1.48 min &amp; 1.97 min, respectively. The assay of the method was validated in human plasma in the concentration range from 307.26-200013.87 pg/ml with the accuracy and precision ranging from 3.86 to 4.87. Recovery studies were found to be 103.79%, 90.93% &amp; 96.83% for HQC, MQC and LQC respectively. The stability of the drug was evaluated in human plasma with different conditions of the auto-sampler, freeze-thaw, bench top, short term and long term stability studies were performed. The method was proved as highly sensitive and selective for the quantification of Apalutamide and determined at the picogram level. There was no matrix effect observed and proved as a stability-indicating method.

Development of polymethacrylate thickener for low pour point transmission oil

The influence of the molecular weight and composition of polyalkyl (meth) acrylate thickeners on the properties NS-3 ultralow pour point naphthenic base oil (Nynas, Sweden) was determined. Using standard experimental techniques, it has been shown that copolymers of higher alkyl methacrylates with C12- C15 alkyl groups, containing 5- 15% methyl methacrylate or butyl methacrylate units and having an average molecular weight М n = 18000- 20000, have good thickening properties and high resistance to mechanical destruction (which are not inferior to the indicators of the used foreign additive Viscoplex 0-220). The results made it possible to develop a thickening additive K-64-03 for low pour point transmission oil, which can be used in highly loaded machinery in the winter conditions of the Far North. Additive K-64-03 exhibits the required thickening properties at elevated and negative temperatures, does not worsen the ultra-low pour point of the base oil (below minus 70°C) and has a high resistance to mechanical destruction.

Butyl methyl imidazolium silica sulfate (BMIm)SS: A novel hybrid nano‐catalyst for highly efficient synthesis of new 1,2-diol monoesters of ibuprofen as the novel prodrugs of ibuprofen having potent analgesic property

The fabrication, characterization of butyl methyl imidazolium silica sulfate [BMIm]SS as a novel nano hybrid catalyst and its application in synthesis of new ibuprofen (IBP) 1,2-diol mono esters were described. [BMIm]SS catalyzed the reaction of IBP with epoxides to afford the new IBP 1,2-diol mono esters in good to excellent yields. The products were tested in vivo for the analgesic properties on female mice using formalin test. The test results revealed that most compounds, in particular compounds 1h, 1k and 1o displayed potent analgesic activity compare to IBP as a reference drug. No mortality was observed due to the toxicity of the synthesized compounds. The docking analysis was conducted that confirmed the strong binding affinity of active compounds to active site of murine cyclooxygenase-2 (COX-2) enzyme compare to IBP. The in silico pharmacokinetic profile, drug likeness and toxicity predictions were carried out for all compounds which determined that 1h can be suggested as an appropriate future drug candidate.

Anti-adhesion properties of aminopropanol derivative with N-alkylaryl radical KVM-194 against Pseudomonas aeruginosa

Introduction. The present study assessed Pseudomonas aeruginosa surface characteristics, motility and adhesion properties under the influence of 1-[4-(1,1,3,3-tetra methyl butyl) phenoxy]-3-(N-benzyl hexa methylene iminium)-2-propanol chloride (KVM-194).&#x0D; Material and methods. The clinical strain P. aeruginosa 449 was used in the study. The cell surface hydrophobicity (CSH) was evaluated by adhesion to solvent (MATS test). Swimming, swarming and twitching motility of P. aeruginosa were studied by standard methods in media with different agar contents. Cells ability to adhere to polystyrene was assessed by the Christensen method. The effect of KVM-194, meropenem and ciprofloxacin on hydrophobicity and motility was evaluated both at 0.5 or 2.0 minimal inhibitory concentrations (MIC), while on adhesion abilities – only 0.5×MIC.&#x0D; Results. It was shown that 0.5× MIC KVM-194 reduced CSH of P. aeruginosa (by 16%, p˂0.05), affected swimming motility, and decreased its adhesion to polystyrene. The most pronounced changes in adhesion properties were recorded after 3-5 hours of pre-treatment with this compound. Moreover, it was proven that sub-MICs of meropenem and ciprofloxacin did not alter bacterial cells hydrophobicity and had no significant influence on P. aeruginosa motility and adhesion properties.&#x0D; Conclusions. The present study suggested that KVM-194 affected the initial steps of P. aeruginosa biofilm formation and thus had tremendous potential for new antibiofilm agents’ development.

FTIR fingerprints discriminate ionic liquids’ antibacterial activity

Ionic liquids (ILs) are those organic salts which exist in liquid form below 100 ​°C. ILs have drawn attention of scientific community due to their increased industrial applications in variety of sectors. In the present study Fourier transform infrared (FTIR) spectroscopy has been utilized to discriminate the antibacterial activities of ILs having different cations and anions against various microorganisms found in the environment. Imidazolium, Pyridinium, Quaternary ammonium and Tetraalkylphosphonium were used as cations in the study whereas, Bromide, Methane sulphonate, Bis(trifluoromethanesulfonyl)imide, Dichloroacetate, Tetrafluoroborate and Hydrogen sulphate were used as anionic parts. High and low ILs relative to antibacterial activity is obtained through m-clust clustering. Mostly ILs formed with Octyl methyl imidazolium (OMIm) and butyl methyl imidazolium (BMIm) show high antibacterial activity against the considered microbes. Spectral base line is corrected through modified polynomial fitting (MPF) with smoothing parameter λ ​= ​1. For discrimination of ILs i.e. high and low antibacterial groups through FTIR spectral data sparse partial least squares discriminant analysis (sPLS-LDA) and jackknife partial least squares logistic regression (jPLS-LR) are used. Spectral wavenumbers selection and model parameters are optimized by maximizing the crossvalidation accuracy. Based on 100 Monte Carlo simulation runs, sPLS-LDA best discriminate ILs groups with 90% validated accuracy. Influential wavelength extracted by sPLS-LDA are used to identify the influential functional compounds i.e. C–Br, C = N, C = CH2, C = CH, C–O and O–H, which discriminate the ILs groups. The results indicated that FTIR fingerprints could be used as a rapid method to discriminate antibacterial activities of ionic liquids.

Simultaneous determination of four endogenous steroids in bio matrices by LC-MS/MS

A simple sensitive and accessible ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometry using AJS-ESI method is established and validated for the intended purpose of quantification of major cholesterol steroidal metabolites Corticosterone, 11α-Hydroxyprogesterone, Testosterone and Progesterone is extracted by Tertiary butyl methyl ether solvent from human plasma and analyzed using Infinity Lab Poroshell 120 EC-C18, (2.1 × 150 mm, 2.7 µm) column by gradient elution. The Eluent composed of 5 milli molar Ammonium formate in Methanol as eluent A and 5 mM Ammonium formate as eluent B and detection was done by AJS- ESI fitted tandem mass spectrometry in positive mode. The internal standard used is Caffeine. The quantification lower limits (LLOQ) are 0.200 ng per liter for all four steroids Corticosterone, 11α-Hydroxyprogesterone, Testosterone and Progesterone. The Calibration curve are linear over the respectively limits of 0.200 to 1000.000 ng per milliliter of Plasma for each analyte and quadric for Testosterone. This new LC-MS/MS method shows presentable precision & accuracy and provides satisfactory sensitive for the fulfillment of human pharmacokinetic studies.