Thiol-functionalized Fe3O4-modified Membrane for Selective Preconcentration and Sensitive Detection of Metallic Copper Nanoparticles in Environmental Waters

Determination of metal oxide nanoparticles and their ionic counterparts in environmental waters by size exclusion chromatography coupled to ICP-MS

Old Nakagawa River is located in eastern part of Tokyo, 6.68km long, and runs along Arakawa River. The river is semi-closed to Arakawa River. River water and sediment samples were collected from 18 and 5 sites from Old Nakagawa River and Arakawa River, respectively. River water samples were analyzed for Na+ and K+ by AAS (atomic absorption spectroscopy), anions (Cl-, SO42-, Br-, NO3-, PO43-) by ion chromatography, and trace metals (Cd, Cr, Cu, Mo, Ni, Pb, Zn) by ICP-MS (inductively coupled plasma mass spectrometry). River sediments samples were analyzed for mineral identification by XRD (X-ray diffraction), and for trace metals (Cd, Cr, Cu, Mo, Ni, Pb, Zn) by ICP-MS. Cr6+ concentrations in river water and sediment samples were analyzed by fixations of Cr6+ by CaHPO4. Five step extraction method by Hall et al. (1996) was used to clarify the proportion of trace metals in each step (extracted solution) for the river sediment samples. I-geo (geoaccumulation index) and EF (enrichment factor) for the trace metals calculated from analytical data on river sediments samples are very high, indicating that the river sediments are highly polluted. Cr6+ in the river water and sediments samples was not detected, although ΣCr in sediments sample is very high, indicating Cr is present as 3+ in the sediments and water, and Cr in sediments is not mobile. Trace metal elements are classified into three groups. They are (A) Cd and Zn which exist mainly as AEC (adsorption- ion exchangeable) and acid soluble (carbonate) fraction, (B) Cu and Pb which exist mainly as amorphous and Fe oxyhydroxide occluded fraction, and (C) Cr and Ni which exist as various fractions.

Functionalization of chitosan with 3-nitro-4-amino benzoic acid moiety and its application to the collection/concentration of molybdenum in environmental water samples

Speciation analysis of chromium by carboxylic group functionalized mesoporous silica with inductively coupled plasma mass spectrometry

With increasing use of bismuth in industry, a better understanding of its environmental behaviour is required, including an improved knowledge of its background concentration range in (non‐saline) freshwaters. However, the poor analytical sensitivity of previous methods may lead to inaccurate measurement results for Bi3+ in environmental samples. In this work, cobalt ion‐assisted photochemical vapour generation (PVG) was developed for the detection of trace Bi with inductively coupled plasma‐mass spectrometry (ICP‐MS) measurement. The volatile species of Bi was found to be (CH3)3Bi generated under UV irradiation in the presence of formic acid, acetic acid and Co2+. The major parameters potentially influencing the detection of Bi were investigated. Under optimised conditions, the limit of detection (3s, n = 11) of the proposed method was 0.3 ng l−1. The analytical sensitivity was enhanced about 70‐fold for Bi3+ compared with that using classic pneumatic nebulisation of ICP‐MS. Furthermore, the proposed method showed better analytical sensitivity and anti‐interference ability towards co‐existing ions compared with ferric ion‐assisted PVG systems. The accuracy of the proposed method was evaluated by analysis of environmental water samples and certified reference materials with satisfactory results.

Stir bar sorptive extraction (SBSE) has been developed in 1999 to efficiently extract and preconcentrate volatile compounds, and many applications have been found after that. This technique conforms to the principles of green chemistry. Here, we used an autosampler with an online thermal desorption unit connected to CGC-MS to analyze pesticides. This study describes the development of a highly sensitive extraction method based on SBSE for simultaneous determination of ultra-trace amounts of four pesticides λ-cyhalothrin, α-cypermethrin, tefluthrin, and dimefluthrin in environmental water samples. This method was compared to the standard liquid–liquid extraction. In this study, a totally solventless SBSE was applied to river and tap water samples for the extraction and preconcentration of four pesticides. PDMS-coated SBSEs of 10 mm × 1 mm thickness were used for this purpose, and SBSEs were directly placed into a large-volume injector of a CGC-MS for thermal desorption of the analytes. In all extractions, deltamethrin was used as an internal standard. This method showed linearity in the range of 1.0–200.0 ng L−1 for cyhalothrin, tefluthrin, and dimefluthrin and 10.0–800 ng L−1 for cypermethrin. Preconcentration factors of 179, 7, 162, and 166 were obtained with very low limits of detection of 0.32, 3.41, 0.36m and 0.69 ng L−1 for cyhalothrin, cypermethrin, tefluthrinm and dimefluthrin, respectively. These detection limits are thousands of times lower than that of the standard method of liquid–liquid extraction. Reproducibility of the method, based on the relative standard deviation, was better than 7.5% and recoveries for spiked tap and river water samples was within the range of 87.83–114.45%. The application of PDMS-coated SBSE coupled with CGC-MS equipped with a large volume injector thermal desorption unit can be used for ultra-trace analysis of environmental water samples. Solventless SBSE offers several advantages over conventional traditional liquid–liquid extraction such as being very fast and economical and provides better extraction without requiring any solvents; so it can be considered as a green method for the analysis of pesticides.

The analysis of environmental samples is widely carried out to determine if a soil is safe for agricultural use, if water is safe to drink, if the air that we breathe can make us sick, how far reaching is pollution, if a contaminated site has been suitably remediated, etc. This article discusses how inductively coupled plasma mass spectrometry (ICPMS) can be used to this end. Indeed, with detection limits at the parts per trillion or even parts per quadrillion level, depending on the element and the instrument, ICPMS is very advantageous for the detection and quantification of toxic or potentially toxic species in environmental samples. This article describes sample preparation for ICPMS analysis and instrument calibration to yield accurate quantitative results. This includes the precautions that are often required, which vary depending on the type of analysis, sample matrix, instrument, and elements to be determined. It also includes techniques that can be coupled to ICPMS to increase its capabilities, such as laser ablation or electrothermal vaporization for direct solid analysis and liquid chromatography, gas chromatography, or capillary electrophoresis for speciation analysis, as speciation information is lost in the inductively coupled plasma (ICP) where all compounds are atomized.

Determination of 18 veterinary antibiotics in environmental water using high-performance liquid chromatography-q-orbitrap combined with on-line solid-phase extraction

Capillary electrophoresis (CE) is a very useful technique which involves the separation of charged species (molecules) on the basis of their movement under the influence of an applied electric field in a capillary format. CE has been developed into rapid, highly effective techniques with extremely high separation power (105–107theoretical plates) and high mass sensitivity (femtomole to zeptomole amounts of substances in nanoliter to picoliter sample volumes) with high potential for separation in the analysis of environmental sample. CE has been compared with ion chromatography (IC) in the inorganic analysis of environmental samples since inorganic ions are usually separated by IC with suppressed conductivity detection. The advantages of CE compared to IC are speed, resolution, and the lack of a need for gradient elution. Operating costs are considerably lower, since ion‐exchange columns are usually expensive. In application, however, limitations imposed by the lack of detection sensitivity complicate the technique's use and impede its wide acceptance. However, as instrumental development continues (especially in detection mode and other techniques for manipulating sensitivity), this limitation will most likely be overcome and a diversity of inorganic species in real samples has already been proved to be amenable to the analysis by CE, and more can be expected in the years ahead.In this article, to understand how CE can be applied to separation and detection of inorganic ions of environmental sample, the basic principles underlying this technique and the operating parameters of CE for inorganic analysis of environmental samples are presented. For trace analysis of environmental samples, methods for manipulating the sensitivity and selectivity control for metal ions are discussed. Techniques such as the coupling of CE with inductively coupled plasma mass spectrometry (ICPMS) are also discussed. Specific applications in real world samples which have complex matrices as well as artificial samples or reference materials are offered to demonstrate the potential of CE in the analysis of environmental pollutants.

A new method of hollow-fiber liquid-phase microextraction (HF-LPME) prior to electrothermal vaporization (ETV) inductively coupled plasma mass spectrometry (ICP-MS) determination of trace Cu, Zn, Pd, Cd, Hg, Pb and Bi, based on gaseous compounds introduction into the plasma as their diethyldithiocarbmate (DDTC) chelates, was developed. The use of the reagent DDTC as chemical modifier could not only enhance the analytical signals, but also decrease the vaporization temperature. At a temperature of 1300 degrees C, trace Cu, Zn, Pd, Cd, Hg, Pb and Bi can be vaporized completely into the ICP. The factors affecting the formation of the chelates and their vaporization behaviors were investigated in detail, and the microextraction conditions were optimized. Under the optimized conditions, the detection limits of the proposed method were 12.4, 28.7, 7.9, 4.5, 3.3, 4.8 and 1.6 pg ml(-1) for Cu, Zn, Pd, Cd, Hg, Pb and Bi, respectively. Enrichment factors of 305, 284, 24, 29, 20, 73 and 43 could be achieved within 15 min of extraction time, and the relative standard deviations (RSDs) for the seven determinations of 0.5 ng ml(-1) of target analytes were 8.8, 6.9, 7.1, 9.4, 10.2, 6.1 and 10.8%, respectively. The newly developed method has been applied to the determination of trace Cu, Zn, Pd, Cd, Hg, Pb and Bi in environmental water and human serum samples, and the recoveries for the spiked samples were in the range of 88-116%. In order to validate this method, two certified reference materials, GBW08501 peach leaves and GBW(E)080040 seawater, were analyzed, and the determined values were in good agreement with the certified values.

For the routine determination of metals in environmental samples, we require microwave-assisted digestion methods that yield ‘total’ or ‘near-total’ recoveries while avoiding the use of HF acid. As inductively coupled plasma mass spectrometry (ICP-MS) is the method of detection, it is desirable to minimize the use of HCl to avoid spectral interferences caused by high Cl– concentrations. Using certified reference materials, we performed a series of modifications to the US EPA method 3051 which included: increasing the temperature and durations of microwave digestion, varying the ratio of sample mass to acid volume, and alterations to the compositions of the acid digestion mixture. The experiments were conducted using urban particulate matter (NIST-1648), coal fly ash (NBS-1633) and six CANMET certified reference materials (Till-2, Till-3, Till-4, LKSD-1, LKSD-2 and LKSD-4), in two laboratories (Health Canada and Environment Canada) using different microwave digestion systems and different ICP-MS instruments. Our modified microwave-assisted nitric acid digestion method improved recoveries for Pb, Zn, V, Fe and Cu approaching ‘total’ recoveries in the same matrices determined using X-ray fluorescence (XRF) and instrumental neutron activation analysis (INAA) as reported in the certificates of analysis. Recoveries for other elements such as Cr and Ni compared well with ‘near-total’ recoveries yielded by traditional (non-assisted) acid digestion methods.

The sequential determination of 14 trace metals, Al, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Mo, Cd, Sb and Pb, in rain and river water samples has been investigated using an inductively coupled plasma mass spectrometry (ICP-MS) with a graphite rod electrothermal vaporizer (ETV) in the presence of the mixed modifier of palladium nitrate and magnesium nitrate. The sensitivity enhancements due to the presence of the modifier were observed for all analyte elements. Detection limits as high as 0.52, 0.13, 0.89, 0.35, 1.76, 0.5, 0.9, 0.5, 0.04, 1.03, 0.28, 0.07, 0.1 and 3.78 pg, respectively, for Al, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Mo, Cd, Sb and Pb have been achieved. For the determination of trace metals in both rain and river water samples by this method, the repeatibility of sample solution were very good, i.e. from 1% to 7% (as a coefficient variation) and the recoveries of elements were good enough, i.e. from 81% to 106%, by using a standard addition method. There was no difference between the results obtained by nebulizer ICP-MS and those obtained by this method, except for zinc and arsenic.

Inductively coupled plasma-mass spectrometry (ICP-MS) method EPA 200.8 is gradually finding acceptance as an alternative to uranium analysis. A comparison of the ICP-MS with the accepted radiochemical method EPA 908.0 has been carried out based on data from laboratory control standards, national proficiency test samples, and environmental and drinking water samples from the State of Utah. The method detection limit (MDL) for ICP-MS was determined to be 0.017 microg/L or (0.011 pCi/L), and the minimum reporting limit (MRL) was 0.17 microg/L (MDL x 10) or (0.11 pCi/L). The minimum reporting limit for radiochemical 908.0 method is 1 pCi/L. Our spiked matrix recoveries, spiked blank samples, and reference materials deviate only a few percentage from the listed true values. Results demonstrate that the ICP-MS is a superior analytical tool for the determination of uranium in drinking and environmental waters at concentrations required by the United States Environmental Protection Agency.

Ethylenediaminetetraacetic acid (EDTA), widely used in chelant formulations for applications to sequester metal ions in solution, has been detected in some environmental waters. Concern has arisen that EDTA, because of its high binding constants with metals, may solubilize metals from sediments in river systems. To address this issue, the effects of EDTA on metal solubilization were examined in a river sediment/water system. Microcosms prepared with authentic Rouge River, Detroit, MI, sediment and water were amended with a range of EDTA concentrations and shaken in the dark at 23°C for 28 d. Metal concentrations were determined by inductively coupled plasma‐optical emission spectroscopy (ICP‐OES) and inductively coupled plasma‐mass spectrometry (ICP‐MS). In the presence of EDTA, 28 d were required for equilibration of dissolved metal species with sediments. Higher levels of trace metals were solubilized by EDTA under oxidizing vs. reducing conditions. Statistically determined (alpha = 0.05) no observed effects levels (NOELs) for metal solubilization by EDTA were generated for the trace metals Ni, Co, Cu, Zn, Cd, Fe, and Pb. These NOELs were 0.4, 0.6, 1.0, 1.0, 3.0, 3.0, and 8.0 µM EDTA, respectively. On a stoichiometric basis, these NOELs were at least fivefold higher than the background level of EDTA present in the river water sample used in this study, indicating that EDTA did not contribute to trace metal solubilization in this system. These results suggest that environmental concentrations of EDTA typically found in river systems for which the subject river is representative, are unlikely to contribute to trace metal solubilization from sediments.

A chitosan resin possessing the leucine moiety (leucine-type chitosan) was newly synthesized by using the chitosan cross-linked with ethylene glycol diglycidyl ether (EGDE) as a basic material. The adsorption behavior of trace amounts of metal ions on the leucine-type chitosan was systematically examined by packing it in a mini-column by ICP-MS (inductively coupled plasma mass spectrometry). Molybdenum was adsorbed on the resin quantitatively and was easily eluted with 1 M nitric acid. The optimized pH range was from 1 to 5, and Mo was collected by the chelation mechanism and/or the anion-exchange mechanism. The method was applied to the determination of Mo in sea and river water samples. A pretreatment with the resin could remove the matrix components in seawater. Preconcentration by 100-fold was accomplished by a column treatment, which had a sufficient concentration to measure trace Mo in river water samples by ICP-AES (inductively coupled plasma atomic emission spectrometry) and GFAAS (graphite furnace atomic absorption spectrometry): LODs with a 100-fold preconcentration by ICP-AES and GFAAS were 0.007 ng mL−1 and 0.009 ng mL−1, respectively, and the RSDs were both within 4.0%.