scholarly journals HPLC-DAD Determination of Iodide in Mineral Waters on Phosphatidylcholine Column

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1243 ◽  
Author(s):  
Małgorzata Tatarczak-Michalewska ◽  
Jolanta Flieger ◽  
Justyna Kawka ◽  
Wojciech Flieger ◽  
Eliza Blicharska
Keyword(s):  
Water Samples ◽  
Mineral Water ◽  
Limit Of Detection ◽  
Direct Determination ◽  
Sample Pretreatment ◽  
Calibration Graph ◽  
Mineral Waters ◽  
Independent Analysis ◽  
Relative Standard

Iodine is an essential nutrient necessary for the production of thyroid hormones. A valuable source of iodide, which is the bio-available iodine form could be mineral waters offered by different spas. In this work, the method capable of direct determination of iodide in mineral water samples based on IAM liquid chromatography on the phosphatidylcholine column (IAM.PC.DD2 Regis HPLC) with DAD detection without sample pretreatment or any pre-concentration steps is presented. The calibration graph for iodide was linear in the range of 0.5–10.0 mg L−1 with a correlation coefficient of 0.9996. The limit of detection was 22.84 ng mL−1. The relative recoveries were in the interval of 98.5–100.2% and the repeatability, expressed as a relative standard deviation (RSD) was less than 5%. The RSA (Response Surface Analysis) investigated the effect of the sample concentration and the injection volume. The iodide concentrations in the mineral water samples ranged from 0.58 to 2.88 mg L−1. The accuracy of the method was assessed through independent analysis by ICP-MS. Iodide levels measured by these two procedures did not significantly differ. The effects of interfering ions like HCO3−, Cl−, SO42−, F−, and Br− were also tested. The analysis has shown insignificant differences in the values of the iodide peak area and its height measured in multicomponent mixtures with an error smaller than 5%.

scholarly journals Determination of cobalt in water samples by atomic absorption spectrometry after pre-concentration with a simple ionic liquid-based dispersive liquid-liquid micro-extraction methodology

2010 ◽  
Vol 8 (3) ◽  
pp. 617-625 ◽  
Author(s):  
Hossein Abdolmohammad-Zadeh ◽  
Elnaz Ebrahimzadeh
Keyword(s):  
Ionic Liquid ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Water Samples ◽  
Limit Of Detection ◽  
Absorption Spectrometry ◽  
Experimental Conditions ◽  
Flame Atomic Absorption ◽  
Relative Standard

AbstractA rapid dispersive liquid-liquid micro-extraction (DLLME) methodology based on the application of 1-hexylpyridinium hexafluorophosphate [C6py][PF6] ionic liquid (IL) as an extractant solvent was applied for the pre-concentration of trace levels of cobalt prior to determination by flame atomic absorption spectrometry (FAAS). 1-Phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) was employed as a chelator forming a Co-PMBP complex to extract cobalt ions from aqueous solution into the fine droplets of [C6py][PF6]. Some effective factors that influence the micro-extraction efficiency include the pH, the PMBP concentration, the amount of ionic liquid, the ionic strength, the temperature and the centrifugation time which were investigated and optimized. In the optimum experimental conditions, the limit of detection (3s) and the enrichment factor were 0.70 µg L−1 and 60, respectively. The relative standard deviation (RSD) for six replicate determinations of 50 µg L−1 Co was 2.36%. The calibration graph using the pre-concentration system was linear at levels 2–166 µg L−1 with a correlation coefficient of 0.9982. The applicability of the proposed method was evaluated by the determination of trace amounts of cobalt in several water samples.

Sensitive quantification of trace zinc in water samples by adsorptive stripping voltammetry

2013 ◽  
Vol 69 (2) ◽  
pp. 438-442 ◽  
Author(s):  
Shahryar Abbasi ◽  
Abbas Farmany ◽  
Mahmoud Roushani ◽  
Seyede Shima Mortazavi
Keyword(s):  
Water Samples ◽  
Mineral Water ◽  
Stripping Voltammetry ◽  
Adsorptive Stripping Voltammetry ◽  
Complexing Agent ◽  
Peak Current ◽  
Relative Standard ◽  
Preconcentration Time ◽  
Influence Of Ph

A simple and sensitive adsorptive stripping voltammetry method was developed for determination of Zn using N-nitrozo-N-phenylhydroxylamine (cupferron) as a selective complexing agent. This complex absorbed on the hanging mercury drop electrode and created a sensitive peak current. The peak current and concentration of zinc accorded with a linear relationship in the range of 0.85–320 ng mL−1. The influence of pH and the nature of supporting electrolytes, concentration of ligand, preconcentration time and applied potential were investigated. The relative standard deviation at a concentration level of 50 ng mL−1 was 1.8%. The method was applied to the determination of zinc in city, river and mineral water samples, with satisfactory results.

scholarly journals Spectrophotometric Determination of Iron(II) after Solid Phase Extraction of Its 2,2′ Bipyridine Complex on Silica Gel-Polyethylene Glycol

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Nahid Pourreza ◽  
Saadat Rastegarzadeh ◽  
Ali Reza Kiasat ◽  
Hossein Yahyavi
Keyword(s):  
Polyethylene Glycol ◽  
Solid Phase Extraction ◽  
Silica Gel ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Extraction Procedure ◽  
Calibration Graph ◽  
Phase Extraction ◽  
Relative Standard

A new solid phase extraction procedure was developed for preconcentration of iron(II) using silica gel-polyethylene glycol (silica-PEG) as an adsorbent. The method is based on retention of iron(II) as 2,2′ bipyridine complex on silica-PEG. The retained complex is eluted by 1.0 mol L−1of sulfuric acid-acetone mixture (1:2) and its absorbance is measured at 518 nm, spectrophotometrically. The effects of different parameters such as pH, concentration of the reagent, eluting reagent, sample volume, amount of adsorbent, and interfering ions were investigated. The calibration graph was linear in the range of 1–60 ng mL−1of iron(II). The limit of detection based on3Sbwas 0.57 ng mL−1and relative standard deviations (R.S.D) for ten replicate measurements of 12 and 42 ng mL−1of iron(II) were 2.4 and 1.7%, respectively. The method was applied to the determination of of iron(II) in water, multivitamin tablet, and spinach samples.

scholarly journals Use of Dispersive Liquid-Liquid Microextraction and UV-Vis Spectrophotometry for the Determination of Cadmium in Water Samples

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
J. Pérez-Outeiral ◽  
E. Millán ◽  
R. Garcia-Arrona
Keyword(s):  
Water Samples ◽  
Limit Of Detection ◽  
Experimental Conditions ◽  
Cadmium Determination ◽  
A Value ◽  
Relative Standard ◽  
Potential Applicability ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

A simple and inexpensive method for cadmium determination in water using dispersive liquid-liquid microextraction and ultraviolet-visible spectrophotometry was developed. In order to obtain the best experimental conditions, experimental design was applied. Calibration was made in the range of 10–100 μg/L, obtaining good linearity (R2 = 0.9947). The obtained limit of detection based on calibration curve was 8.5 μg/L. Intra- and interday repeatability were checked at two levels, obtaining relative standard deviation values from 9.0 to 13.3%. The enrichment factor had a value of 73. Metal interferences were also checked and tolerable limits were evaluated. Finally, the method was applied to cadmium determination in real spiked water samples. Therefore, the method showed potential applicability for cadmium determination in highly contaminated liquid samples.

Determination of diltiazem based on the reduction of Cu(II)–BCA complexes in micellar medium

2010 ◽  
Vol 88 (6) ◽  
pp. 533-539 ◽  
Author(s):  
Larissa Zuppardo Lacerda Sabino ◽  
Daniele Cestari Marino ◽  
Horacio Dorigan Moya
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Confidence Level ◽  
Limit Of Detection ◽  
Calibration Graph ◽  
Micellar Medium ◽  
Solution Ph ◽  
Simple Method ◽  
Relative Standard

A simple method was developed for determining microquantities of diltiazem, based on the reduction of copper(II) in buffered solution (pH 7.0) and the use of a micellar medium containing 4,4′-dicarboxy-2,2′-biquinoline acid. The copper(I) produced reacts with 4,4′-dicarboxy-2,2′-biquinoline acid and the complexes formed are spectrophotometrically measured at 558 nm. A typical calibration graph shows good linearity (r = 0.993) from 20 to 100 μg mL–1 of diltiazem. The limit of detection and relative standard deviation were calculated as 12 μg mL–1 (99% confidence level) and 3.5% (40 μg mL–1; n = 6), respectively, with a mean recovery value of 96.5% found in pharmaceutical dosages. A straightforward and effective way to recycle the reagents is addressed. The hazardous aspects of the Cu(I)–BCA reaction are presented as well.

Determination of Ruthenium in Waste Ruthenium-Loaded Carbon Catalyst Samples Using Teflon Pressure Vessel-Assisted Sample Digestion and ICP-OES

2014 ◽  
Vol 1015 ◽  
pp. 570-573
Author(s):  
Xiao Juan Wei ◽  
Jian Ming Pan
Keyword(s):  
Inductively Coupled Plasma ◽  
Limit Of Detection ◽  
Optical Emission ◽  
Calibration Graph ◽  
Emission Spectrometry ◽  
Carbon Catalyst ◽  
Inductively Coupled ◽  
Relative Standard ◽  
Sample Dissolution

A novel method for the determination of ruthenium in waste ruthenium-loaded carbon catalyst samples was established by inductively coupled plasma optical emission spectrometry after samples digested by Teflon pressure digestion vessel with aqua regia. Such experiment conditions were investigated as the influence of sample dissolution methods, digestion time, digestion temperature and interfering ions on the determination. Under the optimized conditions, the limit of detection (LODs) of Ru for tested solution was 9 ng mL-1. The relative standard deviations (RSDs) for Ru was 2.12 % (CRu= 1 mg L-1, n = 7). The linear range of calibration graph for Ru and Zn was 0 ~ 100.00 mg L-1. The proposed method was applied to determine the practical samples with good recoveries and satisfactory results.

Rapid Direct Determination of Lead in Evaporated Milk by Anodic Stripping Voltammetry Without Sample Pretreatment

1983 ◽  
Vol 66 (6) ◽  
pp. 1409-1413
Author(s):  
Eric W Zink ◽  
Robert A Moffitt ◽  
Wayne R Matson
Keyword(s):  
Anodic Stripping Voltammetry ◽  
Direct Determination ◽  
Sample Pretreatment ◽  
Stripping Voltammetry ◽  
Relative Standard ◽  
Dry Milk ◽  
Anodic Stripping ◽  
Total Analysis ◽  
Sample Range

Abstract The method presented describes the direct determination of lead in evaporated milk in which the milk ashing step prior to analysis is eliminated. Digital instrument readout units are μg Pb /mL milk. Total analysis time after instrument calibration is less than 3 min per sample. Range of the method is 0.05-1.0 ppm lead in milk, and precision of the method expressed by relative standard deviation of duplicate pairs ranged from 30% at 0.1 μg/mL to 3% at 1.0 μg/mL of lead in milk. The method compares favorably with the AOAC official first action anodic stripping voltammetric method (25.074). In addition, the method appears to work equally well for skim evaporated milk, sweetened condensed milk, and nonfat powdered dry milk when the latter two are reconstituted with water according to product label instructions. Recovery and interference studies are presented.

scholarly journals Kinetic-Spectrophotometric Determination of Iodide Based on its Inhibitory Effect on the Decolorization Reaction of Methyl Orange

2009 ◽  
Vol 6 (4) ◽  
pp. 1267-1273
Author(s):  
Reyhaneh Rahnama Kozani ◽  
Ferydoun Ashrafi ◽  
Masuod Khalilnezhad ◽  
Mohammad Reza Jamali
Keyword(s):  
Methyl Orange ◽  
Spectrophotometric Determination ◽  
Limit Of Detection ◽  
Inhibitory Effect ◽  
Calibration Graph ◽  
Reaction Products ◽  
Optimum Conditions ◽  
Relative Standard ◽  
Kinetic Spectrophotometric

A simple, sensitive, rapid and reliable method has been developed for spectrophotometric determination of iodide based on its inhibition effect on the redox reaction between bromate and hydrochloric acid. The decolorization of methyl orange by the reaction products was used to monitor the reaction spectrophotometrically at 525 nm. The variables affecting the rate of the reaction were investigated. Under the optimum conditions, the limit of detection is 1.5 × 10-7mol L-1and calibration range is 2.0 × 10-6–1.3 × 10-4mol L-1of iodide. The linearity range of the calibration graph is depends on bromate concentration. The relative standard deviation of ten-replication determination of 8.2 × 10-5mol L-1iodide was 1.4%. The proposed method was applied to the determination of iodide in natural water samples with satisfactory results.

scholarly journals Rapid, Simple, and Sensitive Spectrofluorimetric Method for the Estimation of Ganciclovir in Bulk and Pharmaceutical Formulations

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Garima Balwani ◽  
Emil Joseph ◽  
Satish Reddi ◽  
Vibhu Nagpal ◽  
Ranendra N. Saha
Keyword(s):  
Standard Deviation ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Calibration Graph ◽  
Limit Of Quantification ◽  
Average Percentage ◽  
Ich Guidelines ◽  
Spectrofluorimetric Method ◽  
Relative Standard

A new, simple, rapid, sensitive, accurate, and affordable spectrofluorimetric method was developed and validated for the estimation of ganciclovir in bulk as well as in marketed formulations. The method was based on measuring the native fluorescence of ganciclovir in 0.2 M hydrochloric acid buffer of pH 1.2 at 374 nm after excitation at 257 nm. The calibration graph was found to be rectilinear in the concentration range of 0.25–2.00 μg mL−1. The limit of quantification and limit of detection were found to be 0.029 μg mL−1and 0.010μg mL−1, respectively. The method was fully validated for various parameters according to ICH guidelines. The results demonstrated that the procedure is accurate, precise, and reproducible (relative standard deviation <2%) and can be successfully applied for the determination of ganciclovir in its commercial capsules with average percentage recovery of 101.31 ± 0.90.

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