scholarly journals Iron-based magnetic molecular imprinted polymers and their application in removal and determination of di- n -pentyl phthalate in aqueous media

2017 ◽  
Vol 4 (8) ◽  
pp. 170672 ◽  
Author(s):  
Jing Li ◽  
Qingxiang Zhou ◽  
Yongyong Yuan ◽  
Yalin Wu
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
Physical Adsorption ◽  
Aqueous Media ◽  
Aqueous Environment ◽  
Chromatography Method ◽  
Molecular Imprinted Polymers ◽  
Imprinted Polymers ◽  
Iron Based

Iron-based magnetic molecular imprinted polymers (Fe@SiO 2 @MIP) were synthesized for highly selective removal and recognition of di- n -pentyl phthalate (DnPP) from water. Well-defined core-shell Fe@SiO 2 nanoparticles (less than 70 nm) were decorated on MIPs reticular layers to endow DnPP-MIPs with magnetic property for the first time. Five other phthalic acid esters including dimethyl phthalate, diethyl phthalate, dipropyl phthalate, di- n -butyl phthalate and di-iso-octyl phthalate were used to investigate the adsorptive selectivity to DnPP. The designed experiments were carried out to explore the adsorption kinetics, isotherms and thermodynamics and the results demonstrated that the adsorption was a spontaneous, exothermal and physical adsorption process. The materials were proved to be excellent adsorbents in removal of DnPP with an adsorption capacity as high as 194.15 mg g −1 in optimal condition. Furthermore, a magnetic solid phase extraction with Fe@SiO 2 @MIP coupled to high-performance liquid chromatography method was successfully developed for the determination of DnPP, and the proposed method achieved a good linear range of 0.5–250 µg l −1 with a correlation coefficient ( R 2 ) of 0.999 and low limit of detection (LOD) of 0.31 µg l −1 . These materials exhibited excellent capacity in removal and highly sensitive identification of DnPP from aqueous environment samples, and opened a valuable direction for developing new adsorbents for the removal and enrichment of important pollutants.

scholarly journals Oxytetracycline Residues in Honey Analyzed by Liquid Chromatography with UV Detection

2013 ◽  
Vol 57 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Anna Gajda ◽  
Andrzej Posyniak ◽  
Andrzej Bober ◽  
Tomasz Błądek ◽  
Jan Żmudzki
Keyword(s):  
Liquid Chromatography ◽  
Oxalic Acid ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Experimental Treatment ◽  
Uv Detection ◽  
Limit Of Quantification ◽  
Chromatography Method ◽  
Liquid Chromatography Method

Summary A liquid chromatography method with UV detection for determination of oxytetracycline (OTC) in honey has been developed. The samples were extracted with the solution of oxalic acid. The clean-up procedure was performed by solid phase extraction (SPE) using polymeric Strata X and carboxylic acid cartridges. Chromatographic separation was carried out on the Luna C8 analytical column with mobile phase consisting of acetonitrile-0.02 M oxalic acid. The method has been successfully validated according to the requirements of the European Decision 2002/657/EC and this method is used in routine control of oxytetracycline in honey samples. The limit of detection (LOD) and limit of quantification (LOQ) of the presented method were 10 and 12.5 μg/kg, respectively. The developed method has also been verified in quantitative determination of oxytetracycline residues in honey after experimental treatment with this product in bee colonies.

scholarly journals A validated high performance liquid chromatography method for determination of three bioactive compounds p-hydroxy benzoic acid, negundoside and agnuside in Vitex species

2015 ◽  
Vol 34 (2) ◽  
pp. 321 ◽  
Author(s):  
Tushar Dhanani ◽  
Sonal Shah ◽  
Satyanshu Kumar
Keyword(s):  
Benzoic Acid ◽  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Hplc Method ◽  
Vitex Negundo ◽  
Limit Of Quantification ◽  
Chromatography Method ◽  
Vitex Species

A validated rapid and simple isocratic HPLC-PDA method was developed for identification and quantification of p- hydroxy benzoic acid and two iridoids negundoside and agnuside in the extracts of two Vitex species, Vitex negundo and Vitex trifolia. The separation of the three compounds was achieved on a RP-18 (250 mm X 4 mm, 5µm) column at 25o C using acetonitrile (15%) and 0.05% trifluoroacetic acid (TFA) in water (85%). Limit of detection (LOD) were 1, 2.5 and 2.5 μg/ml for p- hydroxy benzoic acid, negundoside and agnuside respectively. Similarly, limit of quantification (LOQ) were 2.5, 5 and 5 μg/ml for p- hydroxy benzoic acid, negundoside and agnuside respectively. Good linearity (r2 > 0.999) was observed for all the three compounds in wide concentration range. Using the developed HPLC method, the three compounds were identified and quantified in leaves and bark extracts of Vitex negundo and Vitex trifolia. The novelty of the developed HPLC method is that it does not require complex sample processing such as use of solid phase extraction as well as use of buffer in mobile phase. This is the first report of a validated HPLC method for the simultaneous determination of p- hydroxy benzoic acid, negundoside and agnuside in Vitex species.

scholarly journals Development and Validation of a GMP-Compliant High-Pressure Liquid Chromatography Method for the Determination of the Chemical and Radiochemical Purity of [18F]PSMA-1007, a PET Tracer for the Imaging of Prostate Cancer

2021 ◽  
Vol 14 (3) ◽  
pp. 188
Author(s):  
Ines Katzschmann ◽  
Heike Marx ◽  
Klaus Kopka ◽  
Ute Hennrich
Keyword(s):  
Prostate Cancer ◽  
Quality Control ◽  
Radiochemical Purity ◽  
Control Method ◽  
Solid Phase ◽  
Hplc Method ◽  
Attractive Alternative ◽  
Chromatography Method ◽  
Pet Tracer

For the PET imaging of prostate cancer, radiotracers targeting the prostate-specific membrane antigen (PSMA) are nowadays used in clinical practice. [18F]PSMA-1007, a radiopharmaceutical labeled with fluorine-18, has excellent properties for the detection of prostate cancer. Essential for the human use of a radiotracer is its production and quality control under GMP-compliance. For this purpose, all analytical methods have to be validated. [18F]PSMA-1007 is easily radiosynthesized in a one-step procedure and isolated using solid phase extraction (SPE) cartridges followed by formulation of a buffered injection solution and for the determination of its chemical and radiochemical purity a robust, fast and reliable quality control method using radio-HPLC is necessary. After development and optimizations overcoming problems in reproducibility, the here described radio-HPLC method fulfills all acceptance criteria—for e.g., specificity, linearity, and accuracy—and is therefore well suited for the routine quality control of [18F]PSMA-1007 before release of the radiopharmaceutical. Recently a European Pharmacopeia monograph for [18F]PSMA-1007 was published suggesting a different radio-HPLC method for the determination of its chemical and radiochemical purity. Since the here described method has certain advantages, not least of all easier technical implementation, it can be an attractive alternative to the monograph method. The here described method was successfully validated on several radio-HPLC systems in our lab and used for the analysis of more than 60 batches of [18F]PSMA-1007. Using this method, the chemical and radiochemical purity of [18F]PSMA-1007 can routinely be evaluated assuring patient safety.

scholarly journals DETERMINATION OF 10-GINGEROL IN INDIAN GINGER BY VALIDATED HPTLC METHOD OF SAMPLES COLLECTED ACROSS SUBCONTINENT OF INDIA

2016 ◽  
Vol 8 (12) ◽  
pp. 190
Author(s):  
Kamran Ashraf ◽  
Syed Adnan Ali Shah ◽  
Mohd Mujeeb
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Limit Of Detection ◽  
Limit Of Quantification ◽  
Chromatography Method ◽  
Aluminum Plates ◽  
Layer Chromatography ◽  
Hptlc Method

<p><strong>Objective: </strong>A simple, sensitive, precise, and accurate stability indicating HPTLC (high-performance thin-layer chromatography) method for analysis of 10-gingerol in ginger has been developed and validated as perICH guidelines.</p><p><strong>Methods: </strong>The separation was achieved on TLC (thin layer chromatography) aluminum plates pre-coated with silica gel 60F<sub>254</sub> using n-hexane: ethyl acetate 55:45 (%, v/v) as a mobile phase. Densitometric analysis was performed at 569 nm.</p><p><strong>Results: </strong>This system was found to have a compact spot of 10-gingerol at <em>R</em><sub>F</sub> value of 0.57±0.03. For the proposed procedure, linearity (<em>r</em><sup>2</sup> = 0.998±0.02), limit of detection (18ng/spot), limit of quantification (42 ng/spot), recovery (ranging from 98.35%–100.68%), were found to be satisfactory.</p><p><strong>Conclusion: </strong>Statistical analysis reveals that the content of 10-gingerol in different geographical region varied significantly. The highest and lowest concentration of 10-gingerol in ginger was found to be present in a sample of Patna, Lucknow and Surat respectively which inferred that the variety of ginger found in Patna, Lucknow are much superior to other regions of India.</p>

scholarly journals Determination of 77 Multiclass Pesticides and Their Metabolitesin Capsicum and Tomato Using GC-MS/MS and LC-MS/MS

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1837
Author(s):  
Harischandra Naik Rathod ◽  
Bheemanna Mallappa ◽  
Pallavi Malenahalli Sidramappa ◽  
Chandra Sekhara Reddy Vennapusa ◽  
Pavankumar Kamin ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
Graphitized Carbon Black ◽  
Limit Of Quantification ◽  
Gas And Liquid Chromatography ◽  
Relative Standard ◽  
The Matrix ◽  
Liquid Chromatography Tandem Mass ◽  
Primary Secondary Amine

A quick, sensitive, and reproducible analytical method for the determination of 77 multiclass pesticides and their metabolites in Capsicum and tomato by gas and liquid chromatography tandem mass spectrometry was standardized and validated. The limit of detection of 0.19 to 10.91 and limit of quantification of 0.63 to 36.34 µg·kg−1 for Capsicum and 0.10 to 9.55 µg·kg−1 (LOD) and 0.35 to 33.43 µg·kg−1 (LOQ) for tomato. The method involves extraction of sample with acetonitrile, purification by dispersive solid phase extraction using primary secondary amine and graphitized carbon black. The recoveries of all pesticides were in the range of 75 to 110% with a relative standard deviation of less than 20%. Similarly, the method precision was evaluated interms of repeatability (RSDr) and reproducibility (RSDwR) by spiking of mixed pesticides standards at 100 µg·kg−1 recorded anRSD of less than 20%. The matrix effect was acceptable and no significant variation was observed in both the matrices except for few pesticides. The estimated measurement uncertainty found acceptable for all the pesticides. This method found suitable for analysis of vegetable samples drawn from market and farm gates.

Determination of Bendiocarb Insecticide by Reverse Flow Injection Analysis Using a Solid-Phase Reactor Containing Micro PbO2, Nano PbO2 and Grafted SiO2 - PbO2 Immobilized

2020 ◽  
Vol 42 (1) ◽  
pp. 31-31
Author(s):  
Malik H Alaloosh Alamri Malik H Alaloosh Alamri ◽  
Sadeem Subhi Abed and Abdulkareem M A Alsammarraie Sadeem Subhi Abed and Abdulkareem M A Alsammarraie
Keyword(s):  
Flow Injection ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Reverse Flow ◽  
Blue Color ◽  
Wide Range ◽  
Solid Phase Reactor ◽  
Grafted Nanoparticles ◽  
Reverse Flow Injection

Bendiocarb (BEN) is an acutely toxic carbamate insecticide which used in public places and agriculture, it is also effective against a wide range of nuisance and disease vector insects. A new rapid and sensitive reverse flow injection spectrophotometric procedure coupled with on-line solid-phase reactor is designed in this article for the determination of BEN in its insecticidal formulations and water samples, by using three different solid-phase reactors containing bulk PbO2 (B-SPR), PbO2 nanoparticles (N-SPR) and grafted nanoparticles of SiO2-PbO2 (G-SPR) immobilized on cellulose acetate matrix (CA). This method of oxidative coupling is based on alkaline hydrolysis of the BEN pesticide, and then coupled with N,N dimethyl-p-phenylenediamine sulphate (DMPD) to give a blue color product which measured at λmax 675 nm. It worth to mentioned that under optimal conditions, Beer’s law is obeyed in the range of 1-175 μg mL-1 for B-SPR and 0.25-70 μg mL-1 of BEN for both N-SPR and G-SPR respectively within limit of detection (LOD) of 0.931, 0.234 and 0.210 μg mL-1 for B-SPR N-SPR and G-SPR respectively. The surface methodology of the solid phase was also investigated by using atomic force microscopy.

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