Herbal standardization of formulation containing curcuminoids,piperine and ascorbic acid by dual detection mode densitometric analysis

JPC – Journal of Planar Chromatography – Modern TLC - A dual detection mode high-performance thin-layer chromatographic (HPTLC) method has been evolved for the contemporaneous...     

A validated high-performance thin-layer chromatography method for the quantification of chlorogenic acid in the hydroalcoholic extract of Gynura cusimbua leaves

JPC – Journal of Planar Chromatography – Modern TLC - A simple, reliable, and reproducible high-performance thin-layer chromatography (HPTLC) method was developed for the quantitative...     

A validated high‑performance thin-layer chromatography method for the simultaneous determination of quercetin and gallic acid in Annona reticulata L.

JPC – Journal of Planar Chromatography – Modern TLC - A sensitive and reliable high-performance thin-layer chromatography (HPTLC) method has been developed to simultaneously estimate...     

High-performance thin-layer chromatographic analysis for the simultaneous quantification of lupeol and ursolic acid in the methanolic fraction of four different species of Bauhinia

JPC – Journal of Planar Chromatography – Modern TLC - A high-performance thin-layer chromatography (HPTLC) method for the simultaneous quantitative determination of lupeol and ursolic...     

Identification of 5-methylisoxazole-4-carboxylic acid and 4-(trifluoromethyl)aniline degradation products for leflunomide by high-performance thin-layer chromatography coupled with high-resolution mass spectrometry

JPC – Journal of Planar Chromatography – Modern TLC - This study details the developed high-performance thin-layer chromatographic (HPTLC) method for estimating the active...     

A validated quantification of gallic acid and ellagic acid in Triphala using a high-performance thin-layer chromatography method

JPC – Journal of Planar Chromatography – Modern TLC - A well-known Ayurvedic preparation, Triphala, consists of Amla (Emblica officinalis Gaertn.), Baheda (Terminalia bellirica Roxb.)...     

Simultaneous determination of betulinic acid, β-sitosterol and lupeol in fruits,leaves, root and stem bark of Dillenia pentagyna Roxb. by a validated high-performance thin-layer chromatography method

JPC – Journal of Planar Chromatography – Modern TLC - In the present investigation, a simple and effective high-performance thin-layer chromatography (HPTLC) method was developed and...     

Development and validation of a high-performance thin-layer chromatography method for the simultaneous quantification of rosmarinic acid,quercetin, glycyrrhizin and betulinic acid in polyherbal immunostimulant formulation

JPC – Journal of Planar Chromatography – Modern TLC - Quantification of bioactive markers through modern analytical methods is very essential for establishing the authenticity and...     

Synthesis of Monodisperse Macromolecular Bicyclic and dendritic compounds from (R)-3-hydroxybutanoic acid and benzene-1,3,5-tricarboxylic acid and analysis by fragmenting MALDI-TOF mass spectroscopy

As previously shown, oligo- and poly(β-hydroxyalkanoates) have a high tendency to form lamellar crystallites with ca. 50-Å thickness which corresponds to chain lengths of 16 units (Fig. 1). To have monodisperse model compounds, we have now prepared bicyclic derivatives with three parallel ( 27 – 29 ) or two parallel and an antiparallel chain ( 68 – 70 ) consisting of up to 16 3-hydroxybutanoate (3-HB) units. We also prepared dendritic compounds ( 71 – 75 , 82 – 85 ) containing oligo(3-HB) chains which cannot possibly be arranged as in the lamellae; the branching units were prepared from trimesic acid (= benzene-1,3,5-tricarboxylic acid). So far, none of the prepared samples formed crystals or contained crystalline domains which would have been suitable for single-crystal or powder-diffraction X-ray analysis. The terminally deprotected dendrimers ( 74 , 75 , and 85 ) are multi-anionic (up to 12 peripheral CO₂H groups) and biodegradable. The macromolecular HB derivatives (molecular weight up to 10150 Da) have been fully characterized by IR, ¹H- and ¹³C-NMR, [α]_D, and elemental analysis. Especially important is the analysis by mass spectrometry with the MALDI-TOF technique (Fig. 2), proving that the products are monodisperse; application of a new variation of this MS method (post source decay = PSD or fragment analysis by structural time of flight = FAST^TM) allows for the observation of metastable fragment ions and, thus, is a tool for structural oligomer analysis (Fig. 3).     

Analytical method development for exploring pharmacokinetic profile of ursolic acid in rat tissues by high-performance thin-layer chromatography

JPC – Journal of Planar Chromatography – Modern TLC - A simple and rapid high-performance thin-layer chromatographic (HPTLC) determination of ursolic acid (UA) in tissue is necessary...     

Fatty acid derivatives from the halotolerant fungus Cladosporium cladosporioides

Halotolerant fungus Cladosporium cladosporioides OUCMDZ‐187 was isolated from the mangrove plant Rhizophora stylosa collected in Shankou, Guangxi Province of China. Three new fatty acid esters cladosporesters A–C ( 1 – 3 ) and 5 new fatty acids cladosporacids A–E ( 4 – 8 ) were isolated from the ethyl acetate extract of the fermentation broth of OUCMDZ‐187 in a hypersaline (10% salt) medium. Their structures were elucidated by UV, IR, MS, specific rotation, and 1D and 2D NMR data.     

Application of Ni(II)-imprinted cross-linked poly(methacrylic acid) synthesised through double-imprinting method for the on-line preconcentration of Ni(II) ions in aqueous media

The present paper describes the feasibility of on-line preconcentration of nickel ions from aqueous medium on Ni(II)-imprinted cross-linked poly(methacrylic acid) (IIP) synthesised through a double-imprinting method and their subsequent determination by FAAS. The proposed method consisted in loading the sample (20.0 mL, pH 7.25) through a mini-column packed with 50 mg of the IIP for 2 min. The elution step was performed with 1.0 mol L^?1 HNO₃ at a flow rate of 7.0 mL min^?1. The following parameters were obtained: quantification limit (QL) – 3.74 µg L^?1, preconcentration factor (PF) – 36, consumption index (CI) – 0.55 mL, concentration efficiency (CE) – 18 min^?1, and sample throughput – 25 h^?1. The precision of the procedure assessed in terms of repeatability for ten determinations was 5.6% and 2.5% for respective concentrations of 5.0 and 110.0 µg L^?1. Moreover, the analytical curve was obtained in the range of 5.0–180.0 µg L^?1 (r = 0.9973), and a 1.64-fold increase in the method sensitivity was observed when compared with the analytical curve constructed for the NIP (non-imprinted polymer), thus suggesting a synergistic effect of the Ni(II) ions and CTAB on the adsorption properties of the IIP. The practical application of the adsorbent was evaluated from an analysis of tap, mineral, lake and river water. Considering the results of addition and recovery experiments (90.2–100 %), the efficiency of this adsorbent can be ensured for the interference-free preconcentration of the Ni(II) ions.     

A new and efficient method for the synthesis of 3-(2-nitrophenyl)pyruvic acid derivatives and indoles based on the Reissert reaction

The formation of 3-(2-nitrophenyl)pyruvic acid and its amide and ester derivatives – key compounds for the Reissert indole synthesis – was achieved under various reaction conditions via the acid catalyzed hydrolysis of 5-(2-nitrobenzyliden)-2,2-dimethyl-1,3-oxazolidin-4-one, which is readily available from 3-(2-nitrophenyl)oxirane-2-carboxamide. A new and highly efficient method for the synthesis of indole-2-carboxylic acid derivatives via the intramolecular reductive cyclization of o-nitrophenylpyruvic acid and its amide and ester derivatives was developed using Na₂S₂O₄ in dioxane/water at reflux.     

Prospects for Using Chromatography–Mass Spectrometry for the Determination of Lipids in Clinical Cardiolipidology

Journal of Analytical Chemistry - Cardiolipidology – a new direction in cardiology – is developing intensively owing to the method of mass spectrometry. This method has acquired...     

Development and validation of thin-layer chromatography and high-performance thin-layer chromatography methods for the simultaneous determination of linagliptin and empagliflozin in their co-formulated dosage form

JPC – Journal of Planar Chromatography – Modern TLC - A sensitive, simple and validated thin-layer chromatography (TLC) method (method A) and a high-performance thin-layer...     

A lanthanide nanoparticle-based luminescent probe for folic acid

We report on a novel luminescent method for the detection of folic acid (FA), a member of the vitamin B family. Y₂O₃ nanoparticles were doped with europium(III) ions and surface-modified with captopril. Their fluorescence is quenched by FA, and intensity is a function of folic acid concentration in the 0.1 – 40 μM concentration range. The detection limit is 83 nM of FA at pH 7 and room temperature.

Development and validation of a high-performance thin-layer chromatography densitometric method for the simultaneous determination of novel 1-acridinyl-1,2,3-triazole derivatives

JPC – Journal of Planar Chromatography – Modern TLC - High-performance thin-layer chromatographic (HPTLC) method provides a simple, sensitive, and accurate analytical method for the...     

Analysis of Sulfide Ions by Densitometric Thin-Layer Chromatography and use of TLsee Software

JPC – Journal of Planar Chromatography – Modern TLC - Simple and sensitive TLC-densitometry (method 1) and HPTLC with TLSee software (method 2) have been used for analysis of sulfide...     

Pressurized planar electrochromatography of DNS amino acids derivatives in silica gel and silanized silica gel systems with formic acid addition to the water mobile phase

JPC – Journal of Planar Chromatography – Modern TLC - Pressurized planar electrochromatography (PPEC) of dansyl (DNS) derivatives of amino acids in normal- and reversed-phase systems is...     

Extraction of phthalic acid esters from soil samples using aqueous room temperature sonication coupled to bubble-in-drop single-drop microextraction

ABSTRACT

As a pre-concentration technique, bubble-in-drop, single-drop microextraction has received considerably less attention than its counterparts despite its efficiency, simplicity, eco-friendliness and affordability. Herein, we present the development of this method using a non-chlorinated solvent – dodecane and its application in the extraction and pre-concentration of 17 phthalic acid esters (PAEs) from aqueous samples. The optimised method used 1 µL dodecane and 0.5 µL air bubble, 5% NaCl and a static extraction time of 20 min. The method demonstrates sufficient linearity (R² ≥ 0.9635) and repeatability (%RSD ≤ 20% for n = 27) with the estimated limit of detection in the range 0.23–0.69 ng/mL using the statistical approach for a 17-component standard mixture of the esters. Enrichment factors ranged from 10 to 38 for all the esters, except dimethyl phthalate that did not show any preference to the dodecane solvent used in the study. Application of the technique to contaminated soil samples detected only one ester – bis-(2-ethylhexyl) phthalate (0.62 ng/g of soil), the most common PAE found in most solid waste dumpsite studies due to its wide use in everyday life. The study further highlights the difficulty of extracting the phthalates from soil samples owing to their susceptibility to hydrolysis thereby lowering their extractability from the aqueous solutions which is a prime requirement for the liquid-based microextraction techniques.