• Journal of Korea Soil Environment Society
• /
• v.4 no.1
• /
• pp.3-11
• /
• 1999

The effects of major cations in soils, soil : extractant ratio, and EDTA : lead stoichiometric ratio on the extraction efficiency of lead using EDTA were studied for 4 different actual lead-contaminated soils and one artificially lead-contaminated soil. Extraction of lead from the lead-contaminated soil was not affected by a soil : extractant ratio as low as 1 : 3 but instead was dependent on the quantity of EDTA present. Results of the experiments showed that the extraction efficiency for each soil was different, but if sufficiently large amount of EDTA was applied, all the lead may be extracted except for a soil from lead mining area. The differences in extraction efficiencies nay be due to the major cations present in soils which may compete with lead for active sites on EDTA. The total molar amount of major cations extracted was as muck as 20 times more than the added molar amount of EDTA. For some of the soils tested, the extraction efficiency of lead may be affected by being occluded in the Fe and Mn oxides present in the soil. While major cations present in the soil may be one of the factors affecting lead extraction efficiency, the type of lead species present may also play a role. When these factors affect severely, the using of EDTA to extract lead from lead-contaminated soil might be non-effective method.

• Journal of Industrial and Engineering Chemistry
• /
• v.67
• /
• pp.461-468
• /
• 2018

A highly sensitive, selective and rapid method for the determination of lead based on the reaction of lead (II) with 5-(4'-chlorophenylazo)-6-hydroxypyrimidine-2,4-dione (CPAHPD) and the solid phase extraction of the Pb(II)-CPAHPD complex with Amberlite XAD-2000 was developed, in the presence of pH 5.6 buffer solution and Triton X-114 medium. CPAHPD reacts with lead to form a violet complex with a molar ratio of 2:1 (CPAHPD to lead). This complex was enriched by the solid phase extraction with Amberlite XAD-2000. An enrichment factor of 500 was obtained by elution of the complex from the resin with a minimal amount of isopentyl alcohol(0.2 mL). In isopentyl alcohol medium,the molar absorptivity of the complex is $1.13{\times}10^6L\;mol^{-1}cm^{-1}$ at 647 nm. Beer's law is obeyed in the range of $5.0-160ng\;mL^{-1}$ in the measured solution. The relative standard deviation for 10 replicate samples of $50ng\;mL^{-1}$ level is 1.26%. The detection and quantification limits reaches 1.5 and $4.7ng\;mL^{-1}$ in the original samples. The presented procedure was successfully applied for determination of lead content in real samples such as vegetables, waters, biological and soil samples with satisfactory results.

• Environmental Analysis Health and Toxicology
• /
• v.27
• /
• pp.5.1-5.10
• /
• 2012

Objectives: The purpose of this study was to assess the risk of ingestion exposure of lead by particle sizes of crumb rubber in artificial turf filling material with consideration of bioavailability. Methods: This study estimated the ingestion exposure by particle sizes (more than 250 um or less than 250 um) focusing on recyclable ethylene propylene diene monomer crumb rubber being used as artificial turf filling. Analysis on crumb rubber was conducted using body ingestion exposure estimate method in which total content test method, acid extraction method and digestion extraction method are reflected. Bioavailability which is a calibrating factor was reflected in ingestion exposure estimate method and applied in exposure assessment and risk assessment. Two methods using acid extraction and digestion extraction concentration were compared and evaluated. Results: As a result of the ingestion exposure of crumb rubber material, the average lead exposure amount to the digestion extraction result among crumb rubber was calculated to be $1.56{\times}10^{-4}$ mg/kg-day for low grade elementary school students and $4.87{\times}10^{-5}$ mg/kg-day for middle and high school students in 250 um or less particle size, and that to the acid extraction result was higher than the digestion extraction result. Results of digestion extraction and acid extraction showed that the hazard quotient was estimated by about over 2 times more in particle size of lower than 250 um than in higher than 250 um. There was a case of an elementary school student in which the hazard quotient exceeded 0.1. Conclusions: Results of this study confirm that the exposure of lead ingestion and risk level increases as the particle size of crumb rubber gets smaller.

• Journal of Environmental Health Sciences
• /
• v.24 no.3
• /
• pp.1-5
• /
• 1998

A spectrophotometric method was developed for the acidic solution stripped after an extraction of 0.5 to 2.5 ppm of Lead(II) from 50 mL of $Na_2S_2O_3$ solution into chloroform as the ion-pairs formed between their thiosulfate complexes and alkylamine, Aliquat336. Pb(II) in the stripped solution forms an complex with DDTC in pH 7.3 buffer solution, and was developed in yellow by copper replacement. The ydlow-colored solution have the maximum absorbance at 435 nm in the measurement of absorbance by UV-Visible spectrophotometer. The interference ions such as Fe(III), Hg (II), Al(III), Co, Cu, Ni, Zn, Ca, Sn, have great effects on the extraction, but they were overcomed by the usage of adequate masking agents before an extraction. At last, a good result was obtained in applying this method to synthetic water.

• Journal of Korea Soil Environment Society
• /
• v.4 no.3
• /
• pp.77-84
• /
• 1999

Sequential extraction was applied to characterize the soil-metal binding mechanism in three kinds of soils contaminated with lead and copper The results showed that soil-metal binding was dependent on soil characteristics and metal species. In Munwha dong soil, lead was mainly carbonate form (37.7%), in agriculture soil was associated with amorphous Fe oxide form (23.9%) and in industry area was associated with exchangeable form (22.9%) Meanwhile for copper. organically bound form represented main fraction in most soil and also carbonate and amorphous Fe oxide form showed high fraction. Crystallized Fe oxide and residuals form of copper showed higher fraction than those of lead. Thus, it can be concluded that copper is bound with soil stronger and more difficult wash out Consequently, this mechanism analysis through sequential extraction can provide useful informations for better soil remediation.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.04a
• /
• pp.175-176
• /
• 2004

To develope of efficient method for decontaminating of lead ions from industrial wastewater, treatment of aqueous lead solution with magnetic beads was investigated. Immobilization of carboxyl groups on tile surface of magnetic beads was carried out to introduce chelate effect between lead ions and beads. Experiments were performed with lead solutions and magnetic beads at pH 6. Lead ions were extracted during 1 hour, After extraction, magnetic beads were separated from water by outer magnetic force and the solution was analysed by atomic absorption spectroscopy (AAS). Over 90 % of lead ions could be removed from aqueous solution after beads application. This result indicate that magnetic beads can be used as a efficient method for removing lead ions from industrial wastewater.

• Journal of Magnetics
• /
• v.10 no.3
• /
• pp.89-92
• /
• 2005

The analytic possibility of mobile lead contained in soil has been studied using carboxylated magnetic beads. Extraction of heavy metal was performed to contaminated soil that has been collected and supplied for tests. As experiment materials, soil sample, distilled water and magnetic beads were only used. It means that the lead was extracted under neutral condition. In this condition, only the mobile fraction of lead could be extracted by magnetic beads. The mobile lead in the soil was quickly combined with magnetic beads in the mixture process. Then, the magnetic beads were dissolved into acids after collection by external magnetic force, and the lead combined with the beads was eluted and analyzed by Graphite Furnace Atomic Absorption Spectroscopy (GFAAS). In the results of extraction experiments for 3 sandy soils, the efficiency using beads was similar to or higher than that of EDTA (Ethylendiamintetraacetic acid), which is normally used for analyzing mobile heavy metal concentration in soil. With this, it was shown that this method is a more accurate and simple method to analyze mobile lead when analyzing mobile heavy metal concentration in sandy soil, rather than conventional method using EDTA.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.20 no.6
• /
• pp.307-313
• /
• 2010

Quantitative analytical condition for lead and cadmium in copper contained carbon materials using solvent extraction followed by inductively coupled plasma-atomic emission spectrometry was studied. Copper contained carbon samples were dissolved by nitric acid-perchloric acid digestion. Lead and cadmium were determined after separation with KCN masked copper by an dithizone-chloroform solvent extraction. Recovery efficiency of analyte elements was satisfactory, and most of matrix elements causing interference could be effectively eliminated by the separation. Lead and cadmium were quantitatively determined without influence of sample matrix, by applying it procedure to artifact sample.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 1998.10a
• /
• pp.513-520
• /
• 1998

The evaluation of uncertainty in environmental elemental analysis can be difficult because of the wide variety of analytical sample and objectives. for the specification of measured, elemetal analysis need certain method and high pretreatment technique. The sample of Pb, Cd in paddy soil and sewage sludge were analyzed by same ICP-AES, but each using four different pretreatment technique ; 0.1N HCl extraction, AB-DTPA extraction and two Mixture Acid Digestion. The four technique gave comparable results for the analysis of lead and cadmium. Concentrations determined by Mixture Acid Digestion were more higher than those by 0.1NHCI extraction and AB-DTPA extraction.

• Analytical Science and Technology
• /
• v.20 no.1
• /
• pp.41-48
• /
• 2007

The determination method for the trace lead and cadmium in glass materials was developed by ICP-AES. The lead- and cadmium-DDTC chelates were formed by adding Na-DDTC (sodium diethyldithiocarbamate) as a chelating agent and extracted into MIBK (methyl-isobutyl ketone). Direct measuring of the trace lead and cadmium in glass was not possible because of the interferences of matrix elements as Na, Si, Mg and Ca of glasses unless solvent extraction of lead and cadmium was applied. This procedure was confirmed to be valid quantitative method of Pb and Cd analysis in glass did not influence of sample matrix, by applying it procedure to artifact sample and NIST SRM 1412.