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Shih-Liang Hsi, Peter Surman, Raida Al-Kassas
A highly sensitive and rapid stability indicating Ultra Performance Liquid Chromatographic (UPLC) method was developed for the quantification and identification of isotretinoin in bulk. Chromatographic separation was developed using a gradient elution in a reversed-phase system at flow rate of 0.5 ml/min with 12 minutes run time. The mobile phase was a gradient mixture of mobile phase A (contained a 30:70:0.5 mixture solution of methanol/Purified water/Glacial Acetic Acid) and mobile phase B (contained a 70:25:4...
March 20, 2018: Pharmaceutical Development and Technology
J K Dubey, S K Patyal, Ajay Sharma
In the present day scenario of increasing awareness and concern about the pesticides, it is very important to ensure the quality of data being generated in pesticide residue analysis. To impart confidence in the products, terms like quality assurance and quality control are used as an integral part of quality management. In order to ensure better quality of results in pesticide residue analysis, validation of analytical methods to be used is extremely important. Keeping in view the importance of validation of method, the validation of QuEChERS (quick, easy, cheap, effective, rugged, and safe) a multiresidue method for extraction of 13 organochlorines and seven synthetic pyrethroids in fruits and vegetables followed by GC ECD for quantification was done so as to use this method for analysis of samples received in the laboratory...
March 19, 2018: Environmental Monitoring and Assessment
Xiu-Xiu Zhang, Yi-Zhen Song, Fang Fang, Zhi-Yong Wu
On-site rapid monitoring of nitrite as an assessment indicator of the environment, food, and physiological systems has drawn extensive attention. Here, electrokinetic stacking (ES) was combined with colorimetric reaction on a paper-based device (PAD) to achieve colorless nitrite detection with smartphone. In this paper, nitrite was stacked on the paper fluidic channel as a narrow band by electrokinetic stacking. Then, Griess reagent was introduced to visualize the stacking band. Under optimal conditions, the sensitivity of nitrite was 160-fold increased within 5 min...
March 19, 2018: Analytical and Bioanalytical Chemistry
Muhammad Kamran, Su Wennan, Irshad Ahmad, Meng Xiangping, Cui Wenwen, Zhang Xudong, Mou Siwei, Aaqil Khan, Han Qingfang, Liu Tiening
A field experiment was conducted to investigate the effects of paclobutrazol on ear characteristics and grain yield by regulating root growth and root-bleeding sap of maize crop. Seed-soaking at rate of 0 (CK1), 200 (S1), 300 (S2), and 400 (S3) mg L-1 , and seed-dressing at rate of 0 (CK2), 1.5 (D1), 2.5 (D2), and 3.5 (D3) g kg-1 were used. Our results showed that paclobutrazol improved the ear characteristics and grain yield, and were consistently higher than control during 2015-2016. The average grain yield of S1, S2 and S3 were 18...
March 19, 2018: Scientific Reports
J A Custodio-Mendoza, R A Lorenzo, I M Valente, P J Almeida, M A Lage, J A Rodrigues, A M Carro
A fast and effective method using a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) approach which includes partitioned liquid-liquid extraction (PLLE) and dispersive solid phase extraction (dSPE) clean-up step for the determination of seven 3-monochloropropane-1,2-diol (3-MCPD) fatty acid diesters in vegetable oils is developed and validated according to the Food and Drug Administration (FDA) guidelines. Due to the complexity of the matrices, combination of silica based sorbents (Silica Strong Anion Exchange (Si-SAX), Supel™ QuE Z-Sep+ (Z-Sep+) and Primary Secondary Amine (PSA) were tested for lipid removal...
March 13, 2018: Journal of Chromatography. A
Abbas Ostovan, Hamideh Asadollahzadeh, Mehrorang Ghaedi
This study is devoted on Allura Red as food colorant preconcentration and determination in beverage, fruit juice and drink water samples is based on usage of Mn- and Cu- @ ZnS-NPs-AC as new sorbent for ultrasound-assisted-dispersive solid-phase microextraction (UA-DSPME) combined with ultraviolet-visible spectrophotometric based method (UV-Vis). Contribution of volume of eluent, pH, sorbent mass and sonication time on response following conduction of 28 experiments were optimized and investigated while their significantly justified according to p-value...
May 2018: Ultrasonics Sonochemistry
Yu-Mei Liu, An Zhou, Nian-Jun Yu, Rong-Chun Han, Wei Zhang, Yue-Jian Zhu, Yong Cao, Xiang-Yu Li, Dai-Yin Peng
Epoxy ether type and isophthalene type saponin are the main saponins of Bupleurum chinense. However,due to the difference of their UV spectrum,there is no quantitative method for simultaneous determination of these two kinds of saponins. In this paper,a dual-wavelength high performance liquid chromatography(HPLC) was developed for simultaneous determination of five saponins in epoxidized ether(saikosaponin a,c,d) and isosorbide type(saikosaponin b1,b2). The mobile phase was eluted with acetonitrile-water(0...
January 2018: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
Ji-Yuan Zhang, Xiao-Rui Fan, Xiao-Qian Liu, Xiao-Wei Yu, Li-Xin Yang, Zhi-Ting Guo, Wei-Hong Feng, Zhi-Min Wang, Chun Li
A quantitative nuclear magnetic resonance method(qNMR) was established for determination of the absolute content of febrifugine. Proton nuclear magnetic resonance spectroscopy of febrifugine was obtained in DMSO-d₆ with hydroquinone as the internal standard substance on a Bruker Ascend 600 MHz superconducting nuclear resonance spectrometer at 298 K. The specific parameters were as follows: the observing frequency was 600 MHz,spectra width was 7 211 Hz, pulse width was 9.70 μs, pulse sequence was zg30,scan times was 32 and relaxation time was 2 s...
January 2018: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
Xiao-Fang Wan, Bao-Lian Liu, Teng Yu, Ning Yan, Xin-Sheng Chai, You-Ming Li, Guang-Xue Chen
This work reports on a simple method for the determination of lysine content by an in situ sample pretreatment and headspace gas chromatographic measurement (HS-GC) technique, based on carbon dioxide (CO2 ) formation from the pretreatment reaction (between lysine and ninhydrin solution) in a closed vial. It was observed that complete lysine conversion to CO2 could be achieved within 60 min at 60 °C in a phosphate buffer medium (pH = 4.0), with a minimum molar ratio of ninhydrin/lysine of 16. The results showed that the method had a good precision (RSD < 5...
March 19, 2018: Analytical and Bioanalytical Chemistry
Xue Hua-Li, Bi Yang, Hussain Raza, Wang Hu-Jun, Pu Lu-Mei, Nan Mi-Na, Cheng Xiao-Yan, Wang Yi, Li Yong-Cai
Fusarium rot of muskmelon, caused by Fusarium spp., is one of the most important postharvest decays, that not only causes economic losses but leads to trichothecenes contamination. A rapid and sensitive method was developed for neosolaniol (NEO) analysis in muskmelon inoculated with F. sulphureum, utilizing acetonitrile/water (84:16, v/v) extraction and PriboFast M270 columns purification and UPLC-MS/MS detection. Method validation was evaluated by linearity (R ≥ 0.9990), recovery (88.1-136.9%), precision (RSD ≤ 3...
July 15, 2018: Food Chemistry
A Abellán-Llobregat, C González-Gaitán, L Vidal, A Canals, E Morallón
A new portable electrochemical sensor based on 4-aminobenzoic acid-modified herringbone carbon nanotubes (hCNTs-4ABA/Au-IDA) has been developed for the simultaneous determination of ascorbic acid (AA) and uric acid (UA) in physiological fluids. AA and UA were quantified by chronoamperometry at 0.1 and 0.32 V, respectively, in phosphate buffer solution (PBS 0.25 M, pH 7.0). Significant results were obtained for the separate quantification of AA and UA, with a limit of detection (LOD) of 0.65 μM for both analytes, and sensitivities of (9...
February 23, 2018: Biosensors & Bioelectronics
Stéphane Faucher, Samantha Soulé, Anne-Laure Bulteau, Joachim Allouche, Gaëtane Lespes
A method to determine total gold (Au) and/or silver (Ag) elemental concentrations from gold nanoparticles, Au-Ag nanoshells (NS) and silica coated Au-Ag nanoshells was developed, evaluated and validated. Samples were mineralized in a mixture of concentrated aqua regia and hydrofluoric acid at 65 °C for 4 h. Mineralized solutions were diluted and standard solutions were prepared in aqua regia 5%. ICP-MS analysis was performed with or without the use of a reaction cell (CRC). For the determination of elemental concentrations of nanopowders and test suspensions, the average recovery was 99 ± 2% and 101 ± 2% for gold and silver respectively...
May 2018: Journal of Trace Elements in Medicine and Biology
Chunfeng Liu, Qi Li, Chengtuo Niu, Feiyun Zheng, Yun Zhao
BACKGROUND: Acetaldehyde is an important flavor component in beer, which is possibly carcinogenic to humans. Due to the limit of present detect methods, only the free-state acetaldehyde in beers was focused on, but the acetal in beers had been hardly reported so far. RESULTS: A sensitive HS-GC method was developed for the determination of diethylacetal and acetaldehyde in beer. The column DB-23 was chosen with a total run time of 22.5 min. The optimal addition amount of NaCl, equilibrium temperature and time were 2...
March 15, 2018: Journal of the Science of Food and Agriculture
Charles M Nichols, Jody C May, Stacy D Sherrod, John A McLean
The field of ion mobility-based omics studies requires high-quality collision cross section (CCS) libraries to effectively utilize CCS as a molecular descriptor. Absolute CCS values with the highest precision are obtained on drift tube instruments by measuring the drift time of ions at multiple drift voltages, commonly referred to as a 'stepped field' experiment. However, generating large scale absolute CCS libraries from drift tube instruments is time consuming due to the current lack of high-throughput methods...
March 15, 2018: Analyst
Yinhui Yang, Zhengfeng Chang, Xiaohong Yang, Meiling Qi, Jinliang Wang
Herein we report a propeller-like hexaphenylbenzene-based hydrocarbon material (denoted as BT) as the stationary phase for capillary gas chromatography (GC). The statically-coated BT capillary column showed a high column efficiency of 4340 plates m-1 and weak polarity. Owing to its unique conformation, π-electron toroidal delocalization and intrinsic microporosity, the BT stationary phase exhibited interesting selectivity for aromatic compounds over alkanes. Compared with the graphene (G) column, the BT column showed much prolonged retention and high selectivity for aromatic isomers, especially methylnaphthalenes, dimethylnaphthalenes and phenanthrene/anthracene, mainly because of its propeller-like conformation with rich intercalation effects...
August 3, 2018: Analytica Chimica Acta
Sarah Schatschneider, Salah Abdelrazig, Laudina Safo, Anne Meint Henstra, Thomas Millat, Dong-Hyun Kim, Klaus Winzer, Nigel Peter Minton, David A Barrett
We have investigated the applicability of commercially available lyophilised Spirulina ( Arthrospira platensis), a microorganism uniformly labelled with13 C, as a readily accessible source of multiple13 C-labelled metabolites suitable as internal standards for quantitative determination of intracellular bacterial metabolites. Metabolites of interest were analysed by hydrophilic interaction liquid chromatography coupled with high resolution mass spectrometry. Multiple internal standards obtained from uniformly (U)-13 C-labelled extract from Spirulina were used to enable isotope dilution mass spectrometry (IDMS) for the identification and quantification of the intracellular metabolites...
March 13, 2018: Analytical Chemistry
Edyta Matysiak-Brynda, Barbara Wagner, Michał Bystrzejewski, Ireneusz P Grudzinski, Anna M Nowicka
The way of immobilization of the monoclonal antibody (type IgG) on the electrode surface has a significant effect on the amount of the immobilized protein and in consequence on current signal of protein. Herein, we demonstrate that the application of appropriately functionalized phenyl film allowed us to control the orientation of the antibody (Ab) molecules on the electrode surface. The influence of Ab orientation on the efficiency of antigen-antibody interaction was tested with an example blood plasma protein (ferritin; Ft)...
March 5, 2018: Biosensors & Bioelectronics
Ana Victoria Marta-Sanchez, Sergiane Souza Caldas, Antunielle Schneider, Sónia Maria Vaz Sanches Cardoso, Ednei Gilberto Primel
Parabens have been widely used as antimicrobial agents, mainly in food products, pharmaceuticals, and cosmetics. Although they are known as safe preservatives, they also cause some harm to human health, which has been discussed lately. Therefore, the aim of this study was to evaluate the occurrence of nine parabens (including isomers) in mineral and drinking waters, besides in drinking water treatment sludge (DWTS) samples with determination by liquid chromatography tandem mass spectrometry (LC-MS/MS). Both methods solid phase extraction (SPE) and QuEChERS were validated...
March 10, 2018: Environmental Science and Pollution Research International
Laura Righetti, Andreas Bergmann, Gianni Galaverna, Ottar Rolfsson, Giuseppe Paglia, Chiara Dall'Asta
The recent hyphenation of ion mobility spectrometry (IMS) with high resolution mass spectrometry (HRMS) has risen as a powerful technique for both targeted and non-targeted screening, reducing background noise and allowing separation of isomeric and isobaric compounds. Nevertheless, such an approach remains largely unexplored in food safety applications, such as mycotoxin analysis. To implement ion mobility in routinely MS-based mycotoxin workflows, searchable databases with collusion cross section (CCS) values and accurate mass-values are required...
July 19, 2018: Analytica Chimica Acta
P J Lamas-Ardisana, G Martínez-Paredes, L Añorga, H J Grande
This paper describes a new approach for the massive production of electrochemical paper-based analytical devices (ePADs). These devices are fully fabricated by screen-printing technology and consist of a lineal microfluidic channel delimited by hydrophobic walls (patterned with diluted ultraviolet screen-printing ink in chromatographic paper grade 4) and a three-electrode system (printed with carbon and/or Ag/AgCl conductive inks). The printing process was characterised and optimized for pattern each layer with only one squeeze sweep...
February 28, 2018: Biosensors & Bioelectronics
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