scholarly journals RECOVERY OF GOLD (Au) AND SILVER (Ag) METALS IN THE ELECTRONIC WASTE THROUGH MULTILEVEL PRECIPITATION PROCESS

2016 ◽  
Vol 4 (2) ◽  
pp. 190
Author(s):  
Siti Marwati ◽  
Regina Tutik Padmaningrum ◽  
Sunarto Sunarto
Keyword(s):  
Hydrochloric Acid ◽  
Optimum Condition ◽  
Limit Of Detection ◽  
Electronic Waste ◽  
Atomic Absorption Spectrophotometry ◽  
Precipitation Process ◽  
Soaking Time ◽  
Absorption Spectrophotometry ◽  
Percent Recovery ◽  
Gold Silver

This research aims to determine the percent recovery of gold (Au) and silver (Ag) in the electronic waste such as CD-RW and determine the purity of gold and silver metals in the electronic waste such as CD-RW that through multilevel precipitation process. The first step was the optimization of the concentration of thiourea and time dissolution of gold and silver in the sample. The concentration of thiourea and the time dissolution optimum obtained from conentration of gold and silver maximum. By The percent recovery of gold and silver are determined by comparing the concentration of gold and silver between in the solution sample and in the sample without dissolution that be analyzed by XRF. The scond step was the multilevel precipitation process and calcination. Precipitation and calcination of the filtrat was dissolution results in the optimum condition. Reagent used was a solution of hydrochloric acid and potassium carbonate. The precipitation gold and silver produced from the precipitation of dissolution again and then be analyzed by atomic absorption spectrophotometry. The purity was determined by comparing the weight of gold and silver between in the precipitate and in the solution.  The results of this research showed that the percent recovery of the silver in the CD-RW through the process dissolution with thiourea 10 g/L and 4 hours soaking time were 21.09 %. The purity silver preipitate were 0.15 %. The percent recovery and the purity of gold can  not be determined because the gold contained in the sample were not detected or below the limit of detection equipment. Keywords: recovery, gold, silver, electronic  waste

Optimized atomic absorption spectrophotometry of calcium in erythrocytes.

1987 ◽  
Vol 33 (11) ◽  
pp. 2004-2007 ◽  
Author(s):  
S Nomoto ◽  
S Shoji
Keyword(s):  
Hydrochloric Acid ◽  
Atomic Absorption ◽  
Atomic Absorption Spectrophotometry ◽  
Graphite Tube ◽  
Optimum Conditions ◽  
Absorption Spectrophotometry ◽  
Flame Atomic Absorption ◽  
Flame Atomic Absorption Spectrophotometer ◽  
The Mean ◽  
Mean Concentration

Abstract We sought to establish optimum conditions for measuring calcium in erythrocytes by atomic absorption spectrophotometry. The conditions we selected are as follows. Wash one volume of fresh heparin-treated packed cells once with 30 volumes of isotonic buffered saline (pH 7.4) at a temperature somewhat exceeding 25 degrees C. Dilute the washed packed cells 10-fold with 12 mmol/L hydrochloric acid, and analyze the supernate for calcium. Measure the hematocrit of the washed packed cells, then analyze an aliquot of them for calcium, using a computer-readout type of flame or a non-flame atomic absorption spectrophotometer equipped with a pyrocoated graphite tube. The temperature program is 1000 degrees C for ashing [corrected] and 1800 degrees C for the atomizing cycle. Intraday and day-to-day reproducibility of the assay was 6.55% and 8.19%, respectively, at the mean concentration of calcium in the erythrocytes of healthy adults, which is 4.30 mumol/L.

Biological Conjugate between Antibody and ZnS Nanoparticles as Probe for Atomic Absorption Spectrophotometry Determination of Estriol

2014 ◽  
Vol 556-562 ◽  
pp. 64-66
Author(s):  
Chun Yan Zhang ◽  
Chuan Tao Wang ◽  
Shu Hao Wang ◽  
Ling Yun Du
Keyword(s):  
Atomic Absorption ◽  
Limit Of Detection ◽  
Water Solution ◽  
Semiconductor Nanocrystals ◽  
Atomic Absorption Spectrophotometry ◽  
Serum Samples ◽  
Absorption Spectrophotometry ◽  
Primary Materials ◽  
Good Agreement

ZnS semiconductor nanocrystals (NCs) were prepared by ways from primary materials of ZnCl2 and Na2S in water solution. Using the synthesized ZnS NCs, a polyclonal antibody-based ZnS-labelled immunosorbent assay for the determination of estriol (E3) was developed with atomic absorption spectrophotometry (AAS) as a detector. An immunoaffinity column was applied to testify conjugation between antibody and ZnS NCs. The linear range for determination of estriol is 40.0~600.0 ng.mL-1, and the limit of detection (LOD) is 10.0 ng.mL-1. Some serum samples have been analyzed with satisfactory results which are in good agreement with those obtained using ELISA. This work suggests the potential application of NCs as biological probes and AAS as detector in nonisotopic immunoassay.

Optimum Conditions for Hydride Generation of Selenium and Its Determination by Atomic Absorption Spectrophotometry

1983 ◽  
Vol 66 (1) ◽  
pp. 130-134
Author(s):  
Robert R Brooks ◽  
Janine A Willis ◽  
John R Liddle
Keyword(s):  
Atomic Absorption ◽  
Gas Flow ◽  
Limit Of Detection ◽  
Hydride Generation ◽  
Atomic Absorption Spectrophotometry ◽  
Cold Trap ◽  
Optimum Conditions ◽  
Absorption Spectrophotometry ◽  
Reaction Solution ◽  
Carrier Gas Flow

Abstract Instrumental parameters and other variables were studied to establish the optimum indicators for determination of selenium by atomic absorption spectrophotometry using the hydride generation procedure with cold-trapping. Optimum conditions were established by consideration of the following variables: volume of reaction solution, acid concentration in the reaction mixture, lapse of time after last addition of borohydride, method of addition of borohydride, carrier gas flow rates, position of source beam in the flame cell, oxidation state of selenium, and effect of drying the cold trap between successive determinations. This latter procedure greatly improved the reproducibility of the technique (from ±28% to ±2%. The limit of detection was about 2 ng selenium.

scholarly journals Hepatic iron quantification by atomic absorption spectrophotometry: Full validation of an analytical method using a fast sample preparation

2007 ◽  
Vol 21 (3) ◽  
pp. 161-167 ◽  
Author(s):  
A. C. Wortmann ◽  
P. E. Froehlich ◽  
R. B. Pinto ◽  
R. B. Magalhães ◽  
M. R. Álvares-da-Silva ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Atomic Absorption ◽  
Limit Of Detection ◽  
Bovine Liver ◽  
Atomic Absorption Spectrophotometry ◽  
Hepatic Iron ◽  
Limit Of Quantification ◽  
Absorption Spectrophotometry ◽  
Iron Quantification ◽  
Relative Standard

Atomic absorption spectrophotometry is considered the method of choice for hepatic iron quantification. The objective of the present study was to perform full validation assays of hepatic iron quantification by atomic absorption spectrophotometry, using a fast sample preparation procedure, following the guidelines from the International Conference on Harmonization. The following parameters were evaluated: specificity, linearity/range, precision, accuracy, limit of detection and limit of quantification. A good linear correlation was found (0.9948) in the concentration range evaluated (20- 120 ppb). The relative standard deviations were below 15% for accuracy, and below 10% for both day-to-day reproducibility and within-days precision, and the repeatability of injections was 0.65%. Limit of detection was 2 ppb, and limit of quantification was 6 ppb. Fresh bovine liver tissue was used to evaluate the procedure of collecting samples by liver biopsies. These findings indicate that hepatic iron quantification by atomic absorption spectrophotometry can be reliably performed at the established conditions, and suggest the method is suitable for further use in clinical practice. Hepatic iron quantification by AAS is validated by the experiments performed in the present study.

scholarly journals Penentuan Nilai Ketidakpastian Analisis Merkuri (Hg) pada Daun Labu Menggunakan Solid Sampling Atomic Absorption Spectrophotometry (SS AAS)

2019 ◽  
Vol 1 (1) ◽  
pp. 20-26
Author(s):  
Iwan Sumarlan
Keyword(s):  
Atomic Absorption ◽  
Limit Of Detection ◽  
Toxic Metal ◽  
Atomic Absorption Spectrophotometry ◽  
Experimental Result ◽  
Solid Sampling ◽  
Relative Uncertainty ◽  
Absorption Spectrophotometry ◽  
Solid Form ◽  
Freeze Dryer

Mercury (Hg) is one of the toxic metal which will danger the human body. To detect this metal in the samples, many instrumentations have been employed such as Atomic Absorption Spectrophotometry (AAS). In this research, Hg was analyzed using Solid Sampling Atomic Absorption Spectrophotometry (SS AAS) where its sample is in the solid form.  The preparation of sample was done using Freeze Dryer, an instrument that allows the sample to dry in the low temperature. The experimental result showed that the method has accuracy of 98,65%, precision of 98,34% and limit of detection of 0,00029 ng/g. Hg concentration in the sample was also found to be sebesar 335,069 ng/g with its relative uncertainty and wide uncertainty is 3,7274 ng/g and 7,4548 ng/g respectively. 

Analysis of Mercury in Sportfish Tissue by Thermal Decomposition, Amalgamation/Atomic Absorption Spectrophotometry

2005 ◽  
Vol 68 (4) ◽  
pp. 879-881 ◽  
Author(s):  
J. A. LASRADO ◽  
C. R. SANTERRE ◽  
S. M. SHIM ◽  
J. R. STAHL
Keyword(s):  
Thermal Decomposition ◽  
Atomic Absorption ◽  
Inductively Coupled Plasma ◽  
Total Mercury ◽  
Limit Of Detection ◽  
Fish Tissue ◽  
Atomic Absorption Spectrophotometry ◽  
Inductively Coupled ◽  
Absorption Spectrophotometry ◽  
Mercury In Fish

Sportfish samples (n = 133) that originated from Indiana waters were analyzed for total mercury using inductively coupled plasma/mass spectrometry (ICP/MS) and thermal decomposition, amalgamation/atomic absorption spectrophotometry (TDA/AAS). Total mercury concentrations obtained by the two methods were not significantly different (P > 0.05). The correlation coefficient for total mercury obtained for the two methods was 0.94. The limit of detection using TDA/AAS was 0.1 ppm. TDA/AAS is a preferred technique for the analysis of total mercury in fish tissue because it is rapid (6 min per sample) and easy to use and requires little sample preparation.

Determination of Serum Calcium by Automated Atomic Absorption Spectroscopy

1967 ◽  
Vol 13 (5) ◽  
pp. 388-396 ◽  
Author(s):  
Bernard Klein ◽  
James H Kaufman ◽  
Stanley Morgenstern
Keyword(s):  
Hydrochloric Acid ◽  
Atomic Absorption ◽  
Serum Calcium ◽  
Flow System ◽  
Atomic Absorption Spectrophotometry ◽  
Absorption Spectrophotometry ◽  
Comparison Of The Results ◽  
Automated Determination ◽  
Good Agreement

Abstract A procedure is presented for the automated determination of serum calcium by atomic absorption spectrophotometry. The serum sample, diluted with acidified lanthanum dichloride, is dialyzed against 0.1 N hydrochloric acid and a portion of the recipient solution is pumped into the atomizer-burner of the spectrophotometer. Data are presented on the precision and reproducibility of the flow system. Addition of calcium to serum shows a mean recovery of 99%. A comparison of the results of analyses on random specimens by permanganate titration and the automated procedure shows good agreement.

scholarly journals DETERMINATION OF MINERAL Ca CONTENT IN SEVERAL KINDS OF FRESH FOOD AND PROCESSED PRODUCTS AS SWEETMEAT

2019 ◽  
Vol 1 (2) ◽  
pp. 27-32
Author(s):  
Ahmad Syukur Hasibuan ◽  
Fahma Shufyani ◽  
Rinaldo Rinaldo
Keyword(s):  
Limit Of Detection ◽  
High Sensitivity ◽  
Atomic Absorption Spectrophotometry ◽  
Sensitivity Limit ◽  
Absorption Spectrophotometry ◽  
Fresh Food ◽  
Gas Burner ◽  
Processed Products ◽  
Different Levels

The basic thing that differentiate both is how to make it, lasting power, and design products. This study aims to determine the level of calcium in the sample of fresh guava, ginger, and nutmeg, and to investigate the mineral calcium levels in samples of fresh and processed products as wet sweetmeat and dry sweetmeat. Each sample must first be destructed by dry destruction, then the mineral assay performed with quantitative assay atomic absorption spectrophotometry (AAS) using a gas burner nitrous oxide-acetylene at a wavelength of 422.7 nm. The advantage of this method is to have a high sensitivity (limit of detection of less than 1 ppm), and the implementation is relatively simple. Calcium levels in samples of fresh guava, ginger and nutmeg in a row each each sample as follows (7.7105 ± 0.1224) mg / 100 g, (14.5232 ± 0.117) mg / 100 g and (38, 8834 ± 0.6996) mg / 100 g. In the wet sweetmeat guava, ginger and nutmeg for (13.7787 ± 0.4123) mg / 100 g, (22.8345 ± 0.8247) mg / 100 g and (0.2284 ± 0.3759) mg / 100 g. While on dry sweetmeat guava, ginger and nutmeg for (160.9401 ± 0.4223) mg / 100 g, (176.0465 ± 1.0458) mg / 100 g and (120.4426 ± 0.7932) mg / 100 g. Levels of calcium contained in a sample of fresh guava, ginger and nutmeg and sweetmeat processed as wet and dry sweetmeat has different levels

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