Calibration Curves For Copper Research Articles

On-line quantitative analysis of heavy metals in water based on laser-induced breakdown spectroscopy.

Heavy metal pollution from industrial wastewater is an important source. A method for heavy metals determination in industrial wastewater based on laser-induced breakdown spectroscopy (LIBS) technique was studied and the on-line monitoring system that used automatic graphite enrichment and spatial plasma confinement detection was developed and field demonstrated. The limits of detection (LOD) of heavy metal elements (Cd, Cr, Cu, Ni, Pb, Zn) could reach several μg/L. In Tongling, the on-line heavy metal monitor was field demonstrated. The calibration curves of copper and zinc were built on site, and then on-line monitoring was conducted. The measurement results of this monitor were compared with ICP-OES and had a good correlation. The results showed that the heavy metal monitor could be used for on-line detection of heavy metals in wastewater and had a good reliability.

Analytical Analysis of Different Karats of Gold Using Laser Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Time of Flight Mass Spectrometer (LA-TOF-MS)

Laser induced breakdown spectroscopy (LIBS) coupled with a laser ablation time of flight mass spectrometer (LA-TOF-MS) has been developed for discrimination/analysis of the precious gold alloys cartage. Five gold alloys of Karats 18K, 19K, 20K, 22K and 24K having certified composition of gold as 75, 79, 85, 93 and 99.99% were tested and their precise elemental compositions were determined using the laser produced plasma technique. The plasma was generated by focusing beam of a Nd:YAG laser on the target in air and its time integrated emission spectra were registered in the range 250–870 nm. The calibration free LIBS technique (CF-LIBS) was used for the quantitative determination of the constituent elements present in different Karats of gold. Elemental compositions of these gold alloys were also determined using a Laser Ablation time of flight mass spectrometer (LA-TOF-MS). The LIBS limit of detection was calculated from the calibration curves for copper, silver and gold. Results of CF-LIBS and LA-TOF-MS are in excellent agreement with the certified values. It is demonstrated that LIBS coupled with LA-TOF-MS is an efficient technique that can be used to analyze any precious alloys in a fraction of a second.

Chronocultural sorting of archaeological bronze objects using laser-induced breakdown spectrometry

This work discusses the capability of laser-induced breakdown spectrometry (LIBS) for characterization and cataloging of metallic objects belonging to the Bronze and Iron Ages. A set of 37 metallic objects from different locations of the South East of Iberian Peninsula has been sorted according to their metal content. Arsenic concentration in metallic objects has been found a key factor for distinguishing between Bronze and Iron Ages objects, allowing the chronocultural sorting of each piece. For this study, a pulsed Q-switched Nd:YAG laser was used to generate a microplasma onto the sample surface. To quantify and catalogue these metallic objects, calibration curves for copper, arsenic, tin, lead and iron were established. The quantitative results demonstrate that the chronological sorting carried out by LIBS matches agreeably with archaeological dating criteria.

Copper(II) Determination by Immobilized Urease Inhibition in a Spectrometric Flow-Injection System

ABSTRACTA flow-injection system for analysis of urea and copper(II) ions based on the immobilized urease onto seven modified acrylonitrile copolymer membranes was studied. The most suitable ones for the both flow-injection analysis were selected. The urease systems with membranes modified with NaOH+2-dimethylaminoethyl methacrylate (DMAEM), NaOH+DMAEM+ethylene diamine (EDA) provided higher urea sensitivity and precision of the measurements (R=0.99 and RSD about 3%). The calibration curves for copper (II) ions show that the systems with urease immobilized on membrane modified with NaOH+EDA and hydrazinium sulfate (NH2NH2.H2SO4) had the highest sensitivity to Cu(II). The detection limit of Cu(II) for these systems was 0.1 mg l−1. The correlation coefficient of the linear intervals (R=0.99) and standard deviation (about 4.5 %), which guarantees good reproductivity of the copper analysis. The operational stability of the flow system with membrane modified with NaOH+EDA for analysis of Cu(II) was studied. The investigated immobilized system reached 50% inhibition after 25 days. The stability of immobilized urease membrane during storage was determined. The FIA sensitivity was found to remain almost the same for 40 days. The inhibition effect caused by a mixture of Cu(II), Zn(II) and Ni(II) ions in model solution and real water was also determined.

Quantitative photoacoustic spectrometry : Determination of copper(II) and iron(III) complexed on modified silica gel samples

Calibration curves for copper(II) and iron(III) complexed with N-2-aminoethyl-3-aminoprophyltrimethoxysilane (AEAPS) immobilized on silica gel were prepared separately by photoacoustic spectroscopy (p.a.s.) based on a response function that combines the amplitude and phase values. The concentration of copper and iron in two-component samples are determined by obtaining the response at 600 and 400 nm, respectively, and referring to the calibration graphs. The relative errors in the concentrations determined by p.a.s. compared to atomic absorption spectrometry for copper range from −9.3 to 3.2%, while for iron the range is −52.7 to 4.5%. The large error for iron was due to its low concentration and absorptivity. With suitable chromophores and matrix, the response function extends the linear range of the calibration graph and can be used for nondestructive determination of two components.

The behaviour of copper(II)-selective electrodes in chloride-containing solutions

Calibration curves for copper(II) in solutions containing various chloride ion concentrations are examined in detail. The mechanism of the interferences on the behaviour of the copper(II)-selective electrode is discussed. The anomalous slopes observed can be explained by considering the sensitivity of the electrode membrane to the silver ions released from the electrode surface by chemical interaction with the solution. The effects of the formation of silver-chloride complexes and of the changes in the membrane are described.

Emission spectral analysis with the glow discharge source and a resonance detector

A Grimm-type glow discharge lamp was found to have emission lines which are narrow enough to allow the advantageous use of resonance detection. Design of a cathodic sputtering cell which has an exchangeable cathode is described. The fluorescence signal from this lamp was detected electronically by either a synchronous (lock-in) detection system or a dual-gated integration (boxcar) system. It was found that the dual-gated system improved detection limits by a factor of 50 over the synchronous detection system. Calibration curves for copper in aluminium and silver in gold were found to be linear from the detection limit (about 1 ppm for both elements) up to approximately 20% in the case of copper in aluminium, and 5% silver in gold. Reproducibility of signal measurements was 1%.