High-performance Liquid Technique Research Articles

Variability in inorganic As, Sb and Tl species concentrations in waters and bottom sediments of the Kłodnica River (Poland)

ABSTRACTThe study describes the application of new methodologies for the simultaneous determination of As(III)/As(V), Sb(III)/Sb(V) and Tl(I)/Tl(III) ions in waters and bottom sediments of the Kłodnica River (Poland) with the hyphenated technique of high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) . Time and spatial correlations were determined in the changes of total and speciation concentrations of the above-mentioned analytes in Kłodnica river in 2012. The developed methodologies demonstrate high selectivity and limits of quantification at the level of 0.009–0.120 µg/L. Their repeatability, precision and recovery are appropriate for trace analyses of environmental samples. Time and spatial correlations, and concentrations of inorganic As, Sb and Tl ions demonstrated high variability both in water and bottom sediments.

English

This study aimed to quantify the contents of capsaicinoids (capsaicin, dihydrocapsaicin and nordihydrocapsaicin) in the Capsicum baccatum L. species grown in soil with different concentrations of organic fertilizer (0, 1, 2 and 4%). The quantification of capsaicinoids was made by reverse-phase chromatography using the high-performance liquid technique (HPLC) with ultraviolet (UV) detection. The peppers were harvested from November 2009 to March 2010. The capsaicin content of the fruits of C. baccatum L. was higher for plants grown with organic fertilizer. The highest dihydrocapsaicin contents (10.49 ± 0.38 mg/100 g dry fruits) were obtained from the first harvest of pepper cultivated in soil at 2% organic fertilizer. The content of nordihydrocapsaicin did not change (p≥0.05) with different concentrations of organic fertilizer. The contents of capsaicinoids in pepper fruits varied with the different organic fertilizer concentrations used to grow the crop. Plants grown at 2% organic fertilizer presented the highest capsaicin content, with values of 44.70 ± 3.6 and 50.42 ± 4.80 mg/100 g dry fruits, in the first and second harvest, respectively. Key words: Red pepper, capsaicinoids, capsaicin, organic fertilizer, high performance liquid chromatography (HPLC).

Determination of 6 Selenium Species in Selenium-Enriched Food by Hyphenated Technique of High Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry

A method for the determination of 6 selenium species in selenium-enriched food by hyphenated technique of High Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry( HPLC-ICPMS) has been developed. The 6 selenium species were separated on a Hamilton PRP-X100 analysis column using20 mmol / L citric acid as the mobile phase with pH 6. 0 under gradient elution within 15 min. This method was easy to operate and with remarkably high sensitivity. The detection limits of SeO2!4,SeO2!3,selenomethionine( SeMet),selenocystine( SeCys2),selenourea( SeUr) and selenoethionine( SeEt) were found to be 0. 7,0. 5,4. 1,1. 3,13. 6,11. 9 μg / L for 100 μL injection volume in He collision cell mode of mass spectrometry. Selenium-enriched corn flour containing SeMet was used to investigate the results of different extraction methods. This method has been used to determine selenium species in some kinds of selenium-enriched food,including rice,yeast,tea and ganoderma lucidum spore powder. The results were satisfactory.

Speciation Analysis of Organotin Compounds in Shellfish by Hyphenated Technique of High Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry

The hyphenated technique of high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was applied to the simultaneous determination of five organotin compounds in the shellfish samples. The Agilent TC-C 18 column was used for the separation, the mobile phase of the HPLC was CH 3CN:H 2O:CH 3COOH = 65:23:12 (v/v/v), 0.05% TEA, pH 3.0, at a flow rate of 0.4 ml min −1. A mix standard solution of five mixed organotin compounds from 100 µg l −1 to 0.5 µg l −1 was used for the method assessment. The experimental results indicate that the correlation coefficient of calibration curves ( R 2) for each organotin compound was over 0.998. The shellfish samples were treated by supersonic extraction with the same mobile phase for 30 min. The four organotin compounds including dibutyltin (DBT), tributyltin (TBT), diphenyltin (DPHT), and triphenyltin (TPHT) in the shellfish samples were detected by this method. It was found that the domain compounds in the samples were TBT and TPHT. The recovery tests from the standard addition for TMT, TBT, and TPHT were over 80%. However, the recoveries of DPHT and DBT were relatively low, 37.3% and 75.2%, respectively. The reason might be attributed to the decomposition of those compounds during the extraction procedure.