Determination of Total Chlorine in Chrysotile by X-ray Fluorescence Spectrometry

1994 ◽  
Vol 48 (2) ◽  
pp. 236-240 ◽  
Author(s):  
Régina Zamojska ◽  
Jeff Sharman ◽  
Yvon Cote ◽  
Carmel Jolicoeur
Keyword(s):  
Lower Limit ◽  
Limit Of Detection ◽  
Colorimetric Method ◽  
Standard Addition ◽  
Exchange Chromatography ◽  
Water Soluble ◽  
X Ray ◽  
Limit Of Determination ◽  
A Minor

Energy-dispersive x-ray spectrometric methods have been developed for the determination of chlorine in asbestos (chrysotile) fibers. Chlorine, which is a minor constituent, is determined by a standard addition method from the ground fiber and by a standardless method in six different fibers. The lower limit of detection for a qualitative analysis and the lower limit of determination for a quantitative analysis of chlorine in the asbestos matrix are 40 ppm and 120 ppm, respectively. The water-soluble and acid-soluble chlorine have also been determined by ion-exchange chromatography and by a colorimetric method. The agreement of the three different methods is very good in all cases.

Areas for Improvement in XRF Analysis of Low Atomic Number Elements

1992 ◽  
Vol 36 ◽  
pp. 73-80
Author(s):  
Bruno A.R. Vrebos ◽  
Gjalt T.J. Kuipéres
Keyword(s):  
Lower Limit ◽  
Atomic Number ◽  
Energy Dispersive Spectrometry ◽  
Limit Of Detection ◽  
Heavy Elements ◽  
Fluorescence Spectrometry ◽  
Accurate Analysis ◽  
X Ray ◽  
Made In

Accurate analysis of the light elements has been, from the early applications of X-ray fluorescence spectrometry a struggle compared to the determination of heavy elements in the same matrices. In contrast, there has been virtually no upper limit to the atomic number of the element that could be determined. The lower limit, however, has been continuously adjusted downward through the years. Clearly, the sensitivity as well as the lower limit of detection for the heavy elements have also been improved, but the effect is Jess striking than the advances made in the region of tight element performance. This paper deals specifically with wavelength dispersive sequential x-ray fluorescence spectrometry, although some of the observations made are equally applicable to energy dispersive spectrometry.

Quantitative Determination of Ga, Zn, Cu, Hi, Mn, and Cr by X-Ray Fluorescence in Laterites and Bauxites Using Two Evaluation Methods

1981 ◽  
Vol 25 ◽  
pp. 127-131
Author(s):  
Hasso Schorin
Keyword(s):  
Quantitative Determination ◽  
Chemical Weathering ◽  
Limit Of Detection ◽  
Standard Addition ◽  
Standard Addition Method ◽  
Addition Method ◽  
X Ray ◽  
Minor Elements ◽  
Trace And Minor Elements

Laterites and bauxites are residual products derived from a wide variety of rocks by intensive chemical weathering under strongly oxidizing and leaching conditions. Generally the main constituents of these residues are Fe, Al and Ti present in form of hydroxides and/or oxides. The content of silica depends on the thoroughness of the leaching process. The behaviour of trace and minor elements as Ga, Zn, Cu, Ni, Mn and Cr during the laterite/bauxite formation is not yet well established. Precise and accurate analyses of these elements are a prerequisite for such investigations. In this paper the standard addition method is presented and the results are compared with those obtained by calibration standardization. The accuracy and the precision of the methods as well as the distinction limit and the limit of detection for each element are given.

Determination of Wear Metals in Oil by X-Ray Spectrometry

1985 ◽  
Vol 29 ◽  
pp. 503-509
Author(s):  
Ya-Wen Liu ◽  
A.R. Harding ◽  
D.E. Leyden
Keyword(s):  
Trace Elements ◽  
Thermal Degradation ◽  
Lower Limit ◽  
Organic Material ◽  
Limit Of Detection ◽  
Spectrometric Analysis ◽  
Trace Impurities ◽  
X Ray

AbstractTrace elements in oil may be determined by adsorption of the oil sample onto maguesium oxide followed by thermal degradation of the organic material. The resulting powder is easily pressed into a pellet suitable for X-ray spectrometric analysis. The lower limit of detection depends upon the trace impurities in the MgO and is a few parts per million for most elements determined.

Determination of Uranium in Carbonate Solutions by Extraction onto a Chemically Modified Surface

1977 ◽  
Vol 21 ◽  
pp. 59-69
Author(s):  
Bruce B. Jablonski ◽  
Donald E. Leyden
Keyword(s):  
Lower Limit ◽  
Silica Gel ◽  
Limit Of Detection ◽  
X Ray ◽  
Chemically Modified ◽  
Carbonate Concentration ◽  
Carbonate Solutions ◽  
Modified Surface ◽  
Materials Used

Silica gel treated with a commercial silylation reagent (Dow-Corning Z-6020) has been found to extract uranium from carbonate solutions. The materials used are simple to prepare and once the uranium is extracted, x-ray fluorescence may be employed to determine the uranium directly on the solid. A dependence of the extraction upon carbonate concentration is observed. A lower limit of detection of 2.46 μg of 0.12 ppm uranium from a 20 ml sample is obtained.

scholarly journals Spectrophotometric Determination of Zidovudine in Pharmaceuticals Based on Charge-Transfer Complexation Involving N-Bromosuccinimide, Metol and Sulphanilic Acid as Reagents

2007 ◽  
Vol 4 (2) ◽  
pp. 173-179 ◽  
Author(s):  
K. Basavaiah ◽  
U. R. Anil Kumar
Keyword(s):  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Reference Method ◽  
Standard Addition ◽  
Molar Absorptivity ◽  
Sulphanilic Acid ◽  
Bulk Drug ◽  
Student’S T ◽  
Charge Transfer Complexation

A simple spectrophotometric method is proposed for the determination of zidovudine(ZDV) in bulk drug and in pharmaceutical preparations. The method is based on the oxidation of ZDV by a known excess of oxidant N-bromosuccinimide (NBS), in buffer medium of pH 1.5, followed by the estimation of unreacted amount of oxidant with metol and sulphanilic acid. The reacted oxidant corresponds to the amount ZDV. The purple-red reaction product absorbs maximally at 530 nm and Beer’s law is obeyed over a range 5 to 75 μg mL-1. The apparent molar absorptivity is calculated to be 5.1×103L mol-1cm-1, and the corresponding Sandell sensitivity value is 0.052 μg cm-2. The limit of detection and quantification are found to be 0.90 and 2.72, respectively. Intra-day and inter-day precision and accuracy of the developed methods were evaluated as per the current ICH guidelines. The method was successfully applied to the assay of ZDV in tablet/capsule preparations and the results were statistically compared with those of the reference method by applying the Student’s t-test and F-test. No interference was observed from the common tablet/capsule excipients. The accuracy of the method was further ascertained by performing recovery studies via standard-addition method.

scholarly journals Cerimetric determination of simvastatin in pharmaceuticals based on redox and complex formation reactions

2018 ◽  
Vol 33 (2) ◽  
pp. 21
Author(s):  
Kanakapura Basavaiah ◽  
Okram Zenita Devi
Keyword(s):  
Limit Of Detection ◽  
Reference Method ◽  
Standard Addition ◽  
Molar Absorptivity ◽  
Experimental Conditions ◽  
Spectrophotometric Methods ◽  
Fixed Quantity ◽  
Bulk Drug ◽  
Student’S T

Two sensitive spectrophotometric methods are described for the determination of simvastatin (SMT) in bulk drug and in tablets. The methods are based on the oxidation of SMT by a measured excess of cerium (IV) in acid medium followed by determination of unreacted oxidant by two different reaction schemes. In one procedure (method A), the residual cerium (IV) is reacted with a fixed concentration of ferroin and the increase in absorbance is measured at 510 nm. The second approach (method B) involves thereduction of the unreacted cerium (IV) with a fixed quantity of iron (II), and the resulting iron (III) is complexed with thiocyanate and the absorbance measured at 470 nm. In both methods, the amount of cerium (IV) reacted corresponds to SMT concentration. The experimental conditions for both methods were optimized. In method A, the absorbance is found to increase linearly with SMT concentration (r = 0.9995) whereas in method B, the same decreased (r = -0.9943). The systems obey Beer’s law for 0.6-7.5 and 0.5-5.0 μg mL-1 for method A and method B, respectively. The calculated molar absorptivity values are 2.7 X 104 and 1.06 X 105 Lmol-1 cm-1, respectively; and the corresponding sandel sensitivity values are 0.0153 and 0.0039μg cm-2, respectively. The limit of detection (LOD) and quantification (LOQ) are reported for both methods. Intra-day and inter-day precision, and accuracy of the methods were established as per the current ICH guidelines. The methods were successfully applied to the determination of SMT in tablets and the results were statistically compared with those of the reference method by applying the Student’s t-test and F-test. No interference was observed from the common excipients added to tablets. The accuracy and validity of the methods were further ascertained by performing recovery experiments via standard addition procedure.

scholarly journals ELIMINASI GANGGUAN MATRIKS DALAM ANALISIS MERKURI HG SEBAGAI SENYAWA KOMPLEKS THIO MICHLER’S KETON SECARA SPEKTROFOTOMETRI

2016 ◽  
Vol 11 (1) ◽  
Author(s):  
Sukib Sukib ◽  
Muti'ah Muti'ah
Keyword(s):  
Solvent Extraction ◽  
River Water ◽  
Complex Compound ◽  
Limit Of Detection ◽  
Standard Addition ◽  
Analysis Method ◽  
Addition Method ◽  
Matrix Interferences ◽  
Mercury Analysis

Abstrak. Telah dilakukan penelitian tentang penyusunan metode analisis merkuri melalui pembentukan senyawa kompleks dengan 4,4'-Bis(dimethylamino)thio-benzophenone TMK. Senyawa kompleks tersebut berwarna biru kehijauan yang dapat dideteksi dengan  spektrofoto-meter pada kondisi: lmax 574 nm;  pH 3; konsentrasi TMK 0,0002 M, dan waktu tunggu selama 4–10 menit. perbandingan volume pereaksi: Hg(II), bufer pH 3, TMK 0,002 M, H2O bebas ion adalah 1:1:1:7. Dari hasil penelitian menunjukkan bahwa metode ini telah memenuhi validitas, yaitu: linieritas 0,05–2,0 mg/L, limit deteksi 0,008 mg/L, dan % recovery antara 98% – 102%. Gangguan matriks akibat adanya ion–ion Au(III), Ag(I), Pd(II), Cu(II), Co(II), dan Fe(II) dapat dieliminasi dengan metode ekstraksi pelarut dan adisi standar. Metode adisi standar terbukti mampu memberikan data hasil pengukuran yang dapat dipercaya pada a 5%, yaitu untuk sampel buatan sebesar (0,053 ± 0,001) mg/L, air sungai (0,034 ± 0,004) mg/L, dan sedimen sebesar (4,172 ± 0,050) mg/kg. Dari hasil penelitian ini dapat disimpulkan bahwa metode ekstraksi pelarut dan adisi standar mampu mengeliminasi gangguan matriks pada analisis merkuri sebagai kompleks Hg-TMK secara spektrofotometriKata kunci: Metode analisis merkuri, Thio Michler’s keton, eliminasi, gangguan matriks  Abstract. A research  of analysis method for determination of mercury through formation of complex with 4,4'-bis(dimethylamino)thiobenzophenone TMK has been conducted. The green blue complex compound can be detected with spectrophoto-meter in conditions: lmax 574 nm, buffer acetate pH 3, concentration of TMK 0,0002 M, and the absorbance of complex remains stable for 4–10 minutes. The formula of reagents volume for: Hg(II): buffer acetate pH 3: TMK 0,002 M : de-ionized water is 1:1:1:7. This method is valid, with parameters such as linearity 0.05–2.00 mg/L, limit of detection 0.008 mg/L, and recovery in the range 98%-102%. Matrix interferences that are caused by Au(III), Ag(I), Pd(II), Cu(II), Co(II), and Fe(III) ions can be eliminated with solvent extraction and standard addition methods. Standard addition method is able to give data of trusty measurement result at a 5%, that is for synthesis sample as (0.053 ±  0.001) mg/L, river water (0.034 ± 0.004) mg/L, and for sediment (4.172 ± 0.050) mg/kg. From the result of this research, it can be concluded that solvent extraction and standard addition methods are able to eliminated matrix interferences in mercury analysis as Hg-TMK complex spectrophotometrically Key waords: mercury analysis method, Thio Michler’s ketone, elimination, matrix interferences

scholarly journals Determination of Halofuginone and Amprolium in Chicken Muscle and Egg by Liquid Chromatography

2001 ◽  
Vol 84 (1) ◽  
pp. 43-46 ◽  
Author(s):  
Yuzo Yamamoto ◽  
Fusao Kondo
Keyword(s):  
Lower Limit ◽  
Solid Phase ◽  
Lauryl Sulfate ◽  
Ultraviolet Detection ◽  
Chicken Egg ◽  
Chicken Muscle ◽  
Limit Of Determination ◽  
Cleanup Procedure ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method was developed for simultaneous measurement of halofuginone (HFN) and amprolium (APL) in chicken muscle and egg. HFN and APL were extracted from chicken muscle and egg with acetonitrile. In chicken egg, they were partially purified by solid-phase extraction (SPE) to separate them from impurities. The LC separation was performed on a 4.6 mm id × 250 mm TSK-gel ODS-80TM column using acetonitrile–McIlvaine buffer, pH 3.4, containing 0.01M sodium lauryl sulfate (42 + 58) as the mobile phase. Ultraviolet detection of HFN and APL was performed at wavelengths of 242 and 265 nm, respectively. Recoveries of HFN and APL from chicken muscle spiked at 0.5 μg/g were 74.8 ± 17.7 and 94.2 ± 5.0%, respectively (mean ± standard deviation [SD], n = 10). In chicken muscle, the lower limit of determination for both APL and HFN was 0.03 μg/g. Recoveries of HFN and APL from chicken egg spiked at 0.5 μg/g by a cleanup procedure using SPE were 54.6 ± 3.4 and 85.0 ± 2.4%, respectively (mean ± SD, n = 5). In chicken egg, the lower limit of determination for both APL and HFN was 0.04 μg/g.

scholarly journals Interaction between Amorphous Zirconia Nanoparticles and Graphite: Electrochemical Applications for Gallic Acid Sensing Using Carbon Paste Electrodes in Wine

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 537 ◽  
Author(s):  
Chrys. O. Chikere ◽  
Nadimul Haque Faisal ◽  
Paul Kong-Thoo-Lin ◽  
Carlos Fernandez
Keyword(s):  
Gallic Acid ◽  
Limit Of Detection ◽  
Electrochemical Behaviour ◽  
Differential Pulse ◽  
White Wine ◽  
Zro2 Nanoparticles ◽  
Carbon Paste ◽  
X Ray ◽  
Zirconia Nanoparticles

Amorphous zirconium oxide nanoparticles (ZrO2) have been used for the first time, to modify carbon paste electrode (CPE) and used as a sensor for the electrochemical determination of gallic acid (GA). The voltammetric results of the ZrO2 nanoparticles-modified CPE showed efficient electrochemical oxidation of gallic acid, with a significantly enhanced peak current from 261 µA ± 3 to about 451 µA ± 1. The modified surface of the electrode and the synthesised zirconia nanoparticles were characterised by scanning electrode microscopy (SEM), Energy-dispersive x-ray spectroscopy (EDXA), X-ray powdered diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). Meanwhile, the electrochemical behaviour of GA on the surface of the modified electrode was studied using differential pulse voltammetry (DPV), showing a sensitivity of the electrode for GA determination, within a concentration range of 1 × 10−6 mol L−1 to 1 × 10−3 mol L−1 with a correlation coefficient of R2 of 0.9945 and a limit of detection of 1.24 × 10−7 mol L−1 (S/N = 3). The proposed ZrO2 nanoparticles modified CPE was successfully used for the determination of GA in red and white wine, with concentrations of 0.103 mmol L−1 and 0.049 mmol L−1 respectively.

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