scholarly journals Blank experimental study on the determination of nitrogen and oxygen isotopes by chemical conversion method

RSC Advances ◽  
2019 ◽  
Vol 9 (64) ◽  
pp. 37267-37273
Author(s):  
Yuhan Zong ◽  
Jing Hu ◽  
Yadi Wang ◽  
Hongliang Sun ◽  
Yuliang Li ◽  
...  
Keyword(s):  
Experimental Study ◽  
Nitrous Oxide ◽  
Oxygen Isotopes ◽  
High Sensitivity ◽  
Chemical Conversion ◽  
Simple Operation ◽  
Conversion Method ◽  
Nitrogen And Oxygen Isotopes

The reduction of nitrate to nitrous oxide by chemical conversion has the characteristics of simple operation and high sensitivity.

Determination of Nitrogen and Oxygen Isotopes in Nitrates: A Minireview

2017 ◽  
Vol 50 (13) ◽  
pp. 2045-2057 ◽  
Author(s):  
Shouhui Dai ◽  
Luhua Xie ◽  
Long Peng ◽  
Hui Yang ◽  
Huilong Xu ◽  
...  
Keyword(s):  
Oxygen Isotopes ◽  
Nitrogen And Oxygen Isotopes

Atomic absorption determination of Hg (II), Cd (II), and As (III) in natural and waste water after preliminary group preconcentration

2019 ◽  
Vol 85 (2) ◽  
pp. 12-16
Author(s):  
I. V. Saunina ◽  
E. N. Gribanov ◽  
E. R. Oskotskaya
Keyword(s):  
Waste Water ◽  
Atomic Absorption ◽  
High Sensitivity ◽  
Distribution Coefficients ◽  
Neutral Medium ◽  
Atomic Absorption Determination ◽  
Absorption Determination ◽  
Relative Standard ◽  
Preliminary Group

The sorption of Hg (II), Cd (II), and As (III) by natural aluminosilicate is studied. It is shown that the mineral absorbs those toxicants in a rather wide pH range, quantitative extraction of analytes being achieved in a neutral or close to neutral medium (pH values range within 7.0 - 8.0; 6.3 - 7.5; 7.4 - 8.5 for Hg (II), As (III), and Cd (II), respectively). The effect of the time of phase contact on the degree of extraction of elements is shown. The sorption capacity of the mineral in optimal conditions of the medium acidity (0.06 mmol/g for mercury, 0.31 mmol/g for cadmium, and 0.52 mmol/g for arsenic) is determined. The distribution coefficients attain values of aboutnX 103-nX 104. A new combined method for determination of Hg (II), Cd (II), and As (III) in natural and waste water is developed and tested. The method consists in a preliminary group sorption concentration of the analytes by aluminosilicate, desorption of the analytes from the surface of the mineral and their subsequent atomic absorption determination. The correctness of the method is verified in analysis of spiked samples. The method is easy to use and exhibits high sensitivity, reproducibility and accuracy of analyte determination. The relative standard deviation does not exceed 0.13. Economic availability and possibility of using domestic sorption materials are the important advantages of the proposed procedure which can be used in the practice of laboratories monitoring the quality and safety of environmental objects.

Determination of Selected Phthalates in Some Commercial Cosmetic Products by HPLC-UV

2020 ◽  
Vol 23 (10) ◽  
pp. 1010-1022
Author(s):  
Emrah Dural
Keyword(s):  
High Performance ◽  
Phthalate Esters ◽  
High Sensitivity ◽  
Hplc Method ◽  
Cosmetic Products ◽  
Limit Of Quantification ◽  
Nail Polish ◽  
Accuracy And Precision ◽  
Butyl Phthalate

Aim and scope: Due to the serious toxicological risks and their widespread use, quantitative determination of phthalates in cosmetic products have importance for public health. The aim of this study was to develop a validated simple, rapid and reliable high-performance liquid chromatography (HPLC) method for the determination of phthalates which are; dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), di(2- ethylhexyl) phthalate (DEHP), in cosmetic products and to investigate these phthalate (PHT) levels in 48 cosmetic products marketing in Sivas, Turkey. Materials and Methods: Separation was achieved by a reverse-phase ACE-5 C18 column (4.6 x 250 mm, 5.0 μm). As the mobile phase, 5 mM KH2PO4 and acetonitrile were used gradiently at 1.5 ml min-1. All PHT esters were detected at 230 nm and the run time was taking 21 minutes. Results: This method showed the high sensitivity value the limit of quantification (LOQ) values for which are below 0.64 μg mL-1 of all phthalates. Method linearity was ≥0.999 (r2). Accuracy and precision values of all phthalates were calculated between (-6.5) and 6.6 (RE%) and ≤6.2 (RSD%), respectively. Average recovery was between 94.8% and 99.6%. Forty-eight samples used for both babies and adults were successfully analyzed by the developed method. Results have shown that, DMP (340.7 μg mL-1 ±323.7), DEP (1852.1 μg mL-1 ± 2192.0), and DBP (691.3 μg mL-1 ± 1378.5) were used highly in nail polish, fragrance and cream products, respectively. Conclusion: Phthalate esters, which are mostly detected in the content of fragrance, cream and nail polish products and our research in general, are DEP (1852.1 μg mL-1 ± 2192.0), DBP (691.3 μg mL-1 ± 1378.5) and DMP (340.7 μg mL-1 ±323.7), respectively. Phthalates were found in the content of all 48 cosmetic products examined, and the most detected phthalates in general average were DEP (581.7 μg mL-1 + 1405.2) with a rate of 79.2%. The unexpectedly high phthalate content in the examined cosmetic products revealed a great risk of these products on human health. The developed method is a simple, sensitive, reliable and economical alternative for the determination of phthalates in the content of cosmetic products, it can be used to identify phthalate esters in different products after some modifications.

The atomic absorption spectrometry of molybdenum in the presence of sulphonated aromatic compounds

1981 ◽  
Vol 46 (3) ◽  
pp. 708-716 ◽  
Author(s):  
Josef Komárek ◽  
Vít Mahr ◽  
Lumír Sommer
Keyword(s):  
Nitrous Oxide ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Aromatic Compounds ◽  
High Sensitivity ◽  
Absorption Spectrometry ◽  
Probable Mechanism ◽  
Sodium Salts ◽  
Sulphosalicylic Acid

The effect of sulphonated aromatic compounds on the atomization of molybdenum in acetylene-air and nitrous oxide-acetylene flames was studied. The absorbance signal is increased in the presence of these compounds only in acetylene-nitrous oxide flames and in the presence of potassium or sodium salts. Otherwise, the absorbance is decreased. The probable mechanism of the effect of sulphonated aromatic groups during the atomization of molybdenum is discussed. The determination in the presence of 0.1M 5-sulphosalicylic acid and 9.5 mg ml-1 KCl is without interference and has high sensitivity.

Simultaneous Sorption of Chelates of Elements with Organic Reagents on Amberlite XAD-2 as a Preconcentration Step for the Emission Spectrometric Determination of the Elements

1993 ◽  
Vol 58 (8) ◽  
pp. 1821-1831 ◽  
Author(s):  
Jaroslav Jambor ◽  
Tomáš Javorek
Keyword(s):  
Nitrous Oxide ◽  
Argon Plasma ◽  
Electric Arc ◽  
Emission Spectrometry ◽  
Organic Reagents ◽  
Inductively Coupled ◽  
Simultaneous Sorption

The macrophorous hydrophobic sorbent Amberlite XAD-2 proved to be well suited to the preconcentration of minority amounts of Al, Au, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sn, Ti and V in the form of their chelates with organic reagents. From among 14 reagents tested, 8-hydroxyquinoline and diethyldithiocarbamate appeared most suitable for the quantitative sorption up to level of 1 μg l-1 of analyte. Emission spectrometry served as the analytical finish; the nitrous oxide-acetylene flame, electric arc and inductively coupled argon plasma were chosen according to the nature of the element. The procedure is convenient for the determination of the minority analytes in waters

scholarly journals Electroanalytical Techniques for the Detection of Selenium as a Biologically and Environmentally Significant Analyte—A Short Review

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1768
Author(s):  
Miroslav Rievaj ◽  
Eva Culková ◽  
Damiána Šandorová ◽  
Zuzana Lukáčová-Chomisteková ◽  
Renata Bellová ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Essential Element ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Stripping Voltammetry ◽  
Short Review ◽  
Electroanalytical Methods ◽  
High Concentrations ◽  
Speed Of Analysis

This short review deals with the properties and significance of the determination of selenium, which is in trace amounts an essential element for animals and humans, but toxic at high concentrations. It may cause oxidative stress in cells, which leads to the chronic disease called selenosis. Several analytical techniques have been developed for its detection, but electroanalytical methods are advantageous due to simple sample preparation, speed of analysis and high sensitivity of measurements, especially in the case of stripping voltammetry very low detection limits even in picomoles per liter can be reached. A variety of working electrodes based on mercury, carbon, silver, platinum and gold materials were applied to the analysis of selenium in various samples. Only selenium in oxidation state + IV is electroactive therefore the most of voltammetric determinations are devoted to it. However, it is possible to detect also other forms of selenium by indirect electrochemistry approach.

Urinary gonadotropin measurements by enhanced luminometric assays (LIA) for the evaluation of pubertal development

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
And Demir ◽  
Adem Aydın ◽  
Atilla Büyükgebiz ◽  
Ulf-Håkan Stenman ◽  
Matti Hero
Keyword(s):  
Healthy Subjects ◽  
Reliable Method ◽  
Pubertal Development ◽  
High Sensitivity ◽  
Tanner Stage ◽  
Time Resolved ◽  
Stage 1 ◽  
Sensitive Detection Technique ◽  
Serum And Urine

Abstract Objectives Determination of LH in urine has proved to be a reliable method for evaluation of pubertal development. The human LH assay based on time-resolved immunofluorometric (IFMA) technology (AutoDELFIA, PerkinElmer, Wallac) has been found to be suitable for this purpose thanks to its high sensitivity but other assays have not been evaluated. We have analyzed our data obtained by another potentially sensitive detection technique, enhanced luminometric assay (LIA) with the objective of finding a viable alternative to IFMA since these may not be available in the future. Methods LIA was used to measure LH and FSH in serum and urine samples from 100 healthy subjects of each Tanner stage and both genders, whose pubertal development has been determined. Results Urinary gonodotropin concentrations measured by LIA correlated well with Tanner stage [(r=0.93 for girls, r=0.81 for boys; p<0.01 for LH) and (r=0.81 for girls, r=0.73 for boys; p<0.01 for FSH)]. LIA determinations revealed the increase in U-LH concentrations during the transition from Tanner stage 1–2 in both girls and boys (p<0.001), whereas U-FSH and S-LH were able to detect the increase from Tanner stage 1–2 only in boys or girls, respectively (both p<0.001). Conclusions Measurement of urinary gonadotropin concentrations by LIA may be useful for the evaluation of overall pubertal development and also in the detection of transition from prepuberty to puberty.

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