scholarly journals HPLC-DAD-ESI/MS Identification of Light Harvesting and Light Screening Pigments in the Lake Sediments at Edmonson Point

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Rita Giovannetti ◽  
Leila Alibabaei ◽  
Marco Zannotti ◽  
Stefano Ferraro ◽  
Laura Petetta
Keyword(s):  
Environmental Conditions ◽  
High Performance ◽  
Light Harvesting ◽  
Reversed Phase ◽  
Antarctic Lake ◽  
Esi Ms ◽  
Future Assessment ◽  
Array Detection ◽  
The Antarctic ◽  
Edmonson Point

The composition of sedimentary pigments in the Antarctic lake at Edmonson Point has been investigated and compared with the aim to provide a useful analytical method for pigments separation and identification, providing reference data for future assessment of possible changes in environmental conditions. Reversed phase high performance liquid chromatography (HPLC) with electrospray-mass spectrometry (ESI-MS) detection and diode array detection (DAD) has been used to identify light screening and light harvesting pigments. The results are discussed in terms of local environmental conditions.

scholarly journals Determination of Ten Corticosteroids in Illegal Cosmetic Products by a Simple, Rapid, and High-Performance LC-MS/MS Method

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Vita Giaccone ◽  
Giuseppe Polizzotto ◽  
Andrea Macaluso ◽  
Gaetano Cammilleri ◽  
Vincenzo Ferrantelli
Keyword(s):  
High Performance ◽  
Skin Diseases ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Cosmetic Products ◽  
Chromatography Method ◽  
Esi Ms ◽  
Negative Ionization Mode ◽  
Negative Ionization

The aim of our present work was the development of a rapid high-performance liquid chromatography method with electrospray ionization and tandem mass spectrometry detection (LC-ESI-MS/MS) for the determination of several corticosteroids in cosmetic products. Corticosteroids are suspected to be illegally added in cosmetic preparations in order to enhance the curative effect against some skin diseases. Sample preparation step consists in a single extraction with acetonitrile followed by centrifugation and filtration. The compounds were separated by reversed-phase chromatography with water and acetonitrile (both with 0.1% formic acid) gradient elution and detected by ESI-MS positive and negative ionization mode. The method was validated at the validation level of 0.1 mg kg−1. Linearity was studied in the 5–250 μg L−1 range and linear coefficients (r2) were all over 0.99. The accuracy and precision of the method were satisfactory. The LOD ranged from 0.085 to 0.109 mg kg−1 and the LOQ from 0.102 to 0.121 mg kg−1. Mean recoveries for all the analytes were within the range 91.9–99.2%. The developed method is sensitive and useful for detection, quantification, and confirmation of these corticosteroids in cosmetic preparations and can be applied in the analysis of the suspected samples under investigation.

scholarly journals Inhibitory effect of the glucosinolate–myrosinase system on Phytophthora cinnamomi and Pythium spiculum

2019 ◽  
Vol 55 (No. 2) ◽  
pp. 93-101 ◽  
Author(s):  
Francisco Teodoro Arroyo Cordero ◽  
Rocío Rodríguez-Arcos ◽  
Ana Jiménez-Araujo ◽  
Rafael Guillén-Bejarano ◽  
María José Basallote ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
High Performance ◽  
Phytophthora Cinnamomi ◽  
Inhibitory Effect ◽  
Reversed Phase ◽  
Field Application ◽  
Additional Information ◽  
Array Detection ◽  
Important Additional Information

Glucosinolate extracts from sprouts of common Brassica nigra, B. juncea cv. Scala, B. carinata cv. Eleven, and Sinapis alba cv. Ludique were analysed by reversed phase high-performance liquid chromatography-diode array detection-mass spectrometry. The effect of the glucosinolate–myrosinase system on in vitro mycelial growth of Phytophthora cinnamomi Rands and Pythium spiculum B. Paul was assessed. Likewise, sinigrin and sinalbin monohydrate commercial standards were also tested. The extracts from B. carinata, which contained 159 mmol/g plant DW equivalent (85% sinigrin, 5% gluconapin, and 3% glucotropaeolin), were the most effective against Phytophthora and Pythium isolates used in this study. However, the extract from S. alba, which contained 1 180 mmol/g (100% sinalbin), did not inhibit the mycelial growth of the isolates tested. The use of the glucosinolate-myrosinase system provides important additional information to advance in the implementation of field application of brassicaceous amendments for the control of soil-borne pathogens.

Development of a Method for the Determination of Pyrimethamine Concentrations in Feeds by Ion-Pairing High-Performance Liquid Chromatography

2002 ◽  
Vol 65 (4) ◽  
pp. 688-691 ◽  
Author(s):  
P. S. GONG ◽  
S. L. JENG ◽  
Y. F. HSU ◽  
C. C. LIN ◽  
S. Y. LIN
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Ion Pairing ◽  
Reversed Phase ◽  
Hplc Method ◽  
Alumina Column ◽  
Tetramethylammonium Chloride ◽  
Array Detection

An ion-pairing reversed-phase high-performance liquid chromatography (HPLC) method with diode array detection at 280 nm was developed to determine pyrimethamine concentrations in feed for laying hens. Pyrimethamine was extracted with a mixture of 5% isobutanol and 95% benzene, and the extract was cleaned up on an alumina column. The drug was eluted from an Intersil ODS-3V column (250 by 4.6 mm) with a mixture of 25% acetonitrile and 75% water (vol/vol) containing 0.01 M tetramethylammonium chloride as an ion-pairing agent and adjusted with acetic acid to pH 3.5. The flow rate was 1.0 ml/min. Mean recovery of pyrimethamine from supplemented feeds at concentrations of 2, 4, and 5 μg/g of feed were 100.5, 103.5, and 100.8%, respectively. Precision within a day ranged from 4.3 to 7.0% for the three concentrations, and day-to-day precision was 5.3% for feed supplemented at a concentration of 4 μg/g. No chromatographic interference was detected from other 2,4-diaminopyrimidine compounds or other major drugs used in poultry.

scholarly journals Constituents of Da-Cheng-Qi Decoction and its Parent Herbal Medicines Determined by LC-MS/MS

2010 ◽  
Vol 5 (5) ◽  
pp. 1934578X1000500
Author(s):  
Fengguo Xu ◽  
Ying Liu ◽  
Rui Song ◽  
Haijuan Dong ◽  
Zunjian Zhang
Keyword(s):  
High Performance ◽  
Herbal Medicines ◽  
Gradient Elution ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Esi Ms ◽  
Chemical Constitution ◽  
Tandem Mass Spectrometric ◽  
Liquid Chromatographic ◽  
First Time

Da-Cheng-Qi decoction (DCQD) is a purgative prescription used in China and East Asia. To profile the constituents of this complex traditional Chinese medicine (TCM), a high-performance liquid chromatographic, electrospray ionization, tandem mass spectrometric (HPLC-ESI/MS/MS) analytical method was developed. After separation on a reversed-phase C18 analytical column using gradient elution, samples were analyzed by ESI-MS/MS in negative mode. As a result, a total of 37 compounds were detected, of which two tannins, three anthraquinones, two sennosides, five flavonoids and two lignans were unambiguously identified by comparison with standard compounds, and sixteen compounds were either tentatively identified or deduced according to their MS/MS data. The fragmentation pathways of many of the observed compounds, such as the tannins and lignans are reported for the first time. In addition, the identity of each peak in DCQD was explored by comparison with those of its three constituent herbs. The results indicated that tannins, anthraquinones and sennosides in DCQD originated from Radix et Rhizoma Rhei, flavonoids from Fructus Aurantii Immaturus, and lignans from Cortex Magnoliae officinalis. The present study provides an example of chemical constitution profiling in complex TCM systems using LC/MS/MS.

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