Chu-Fang Wang

Lead determination in whole blood by laser ablation coupled with inductively coupled plasma mass spectrometry

This work describes a simple procedure for blood lead level determination. The proposed method requires little sample pretreatment and subsequent direct analysis of a dried blood spot on a filter membrane using laser ablation coupled with inductively coupled plasma mass spectrometry (LA-ICP-MS). In general, LA-ICP-MS studies are somewhat limited by the lack of matrix-matched standards for calibration purposes. Here we describe aqueous standard calibration and matrix-matched calibration methods. This method was validated by analysis of the reference materials. With the matrix-matched calibration method, the recovery ranged from 97.8% to 112.8%, while the aqueous standard calibration method ranged 90.4% to 122.4%. The lower detection limit was estimated as 0.1 ng mL(-1). The determination precision, expressed as the relative standard deviation (RSD), was not worse than 10% for all results. A sample throughput of approximately 5 min per sample made it possible to rapidly screen a large number of samples.

Characteristics of elements in waste ashes from a solid waste incinerator in Taiwan

Incineration, one of the most effective methods used to treat solid wastes, reduces the volume of solid wastes significantly and enables recovery of thermal energy. However, during this waste treatment, a small amount of heavy metals can be present in the form of fly ash or vapor in the flue gas, becoming a threat to human health and other living organisms once emitted into the environment. This study focuses on the characteristics and behavior of elements contained in the combustion residues and their impact on various wastes at Taiwans municipal solid waste incinerator (MSWI). Three kinds of waste, municipal solid waste (MSW), industrial waste (IW), and biomass waste (BM), were analyzed to obtain their physical properties and elemental composition before incineration. The combustion residues were collected with a sampler at various locations such as the furnace bottom, a heat economizer, a semi-dry scrubber, a bag-house filter and a gas stack. Twenty-one elements were determined to establish the actual mass fraction and to estimate the possible impact on the environment. Owing to its volatility, Cd was found in high concentrations in bag-house filter ash. In addition, the mass fraction of Zn, As, Pb, Sb and V in bag-house filter ash was found greater than 20% for the three kinds of wastes. Iron (Fe) content was found to be high in MSW, S, Cd, Ni, Pb and Sb content were high in IW and Se content was high in BW.

Characteristics of Road Dust from Different Sampling Sites in Northern Taiwan

Abstract Road dust contributes a large percentage of the atmosphere’s suspended particles in Taiwan. Three road dust samples were collected from downtown, electrical park, and freeway tunnel areas. A mechanical sieve separated the road dust in the initial stage. Particles >100 μm were 75%, 70%, and 60% (wt/wt), respectively, of the samples. Those particles <37 μm were resuspended in another mixing chamber and then collected by a Moudi particle sampler. The largest mass fraction of resuspended road dust was in the range of 1–10 μm. Ultrafine particles (<1 μm) composed 33.7, 17, and 7.4% of the particle samples (downtown, electrical park, and freeway tunnel, respectively). The road dust compositions were analyzed by inductively coupled plasma (ICP)-atomic emissions spectroscopy and ICP-mass spectrometry. The highest concentration fraction contained more aluminum (Al), iron (Fe), calcium (Ca), and potassium than other elements in the road dust particle samples. Additionally, the sulfur (S) content in the road dust from the electrical park and freeway tunnel areas was 2.1 and 3.4 times the downtown area sample, respectively. The sulfur originated from the vehicle and boiler oil combustion and industrial manufacturing processes. Furthermore, zinc (Zn) concentration in the tunnel dust was 2.6 times that of the downtown and electrical park samples, which can be attributed to vehicle tire wear and tear. Resuspended road dusts (<10 μm) from the downtown and freeway tunnel areas were principally 2.5–10 μm Al, barium (Ba), Ca, copper (Cu), Fe, magnesium (Mg), sodium (Na), antimony (Sb), and Zn, whereas arsenic (As), chromium (Cr), and nickel (Ni) were predominant in the ultrafine particle samples (<1 μm). Al, Ba, and Ca are the typical soil elements in coarse particles; and As, and Cr and Ni are the typical fingerprint of oil combustion and vehicle engine abrasion in ultrafine particles. There was a special characteristic of resuspension road dust at electrical park, that is, many elements, including As, Ba, Ca, cadmium, Cr, Cu, Fe, manganese (Mn), Ni, lead (Pb), S, vanadium (V), and Zn, were major in ultrafine particles. These elements should be attributed to the special manufacturing processes of electric products.

Multi-element analysis of airborne particulate matter by various spectrometric methods after microwave digestion

Abstract A microwave digestion procedure in combination of the measurement of various spectrometric methods including atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry was developed for the multi-element analysis of airborne particulate matter collected on PTFE filters by a dichotomous sampler. In order to achieve more sensitive and rapid multi-element analyses, special PTFE-lined digestion vessels were used. It was found that complete digestion of airborne particulates with an acid mixture of HNO3-HClO4-HF (3:7:1, v v ) can be achieved in the microwave-irradiated closed vessel system and direct spectroscopic measurement of the digested sample after appropriate dilution. A recovery study was conducted using a multi-element standard and NIST Standard Reference Material 1648 Urban Particulate. Sixteen major, minor, and trace elements in airborne particulate matter were determined.

Microwave decomposition for airborne particulate matter for the determination of trace elements by inductively coupled plasma mass spectrometry

A microwave digestion method utilizing an acid mixture of HNO3–HClO4–HF (3 + 5 + 2 v/v) in closed vessels was developed for the determination of major, minor and trace elements in very small amounts of airborne particulate matter collected on Teflon filters by a dichotomous sampler, and was tested on NIST Standard Reference Material (SRM 1648 Urban Particulate Matter). Analyses were carried out by inductively coupled plasma mass spectrometry (ICP-MS). Sixteen elements (Al, As, Ba, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sb, V and Zn) were determined. The results generally showed high reproducibility and good agreement with the certified values, except for As and Cr. The feasibility of applying the microwave digestion pre-treatment with ICP-MS to real samples was also examined. It was demonstrated that the suggested method is more suitable than conventional methods for real sample analysis.

Determination of chromium in airborne particulate matter by high resolution and laser ablation inductively coupled plasma mass spectrometry

Abstract This work presents an optimized sample digestion procedure for determining Cr in airborne particulate matter by inductively coupled plasma mass spectrometry (ICP-MS). High resolution (HR) ICP-MS is utilized to examine how the added acid mixture and subsequent evaporation process influence spectroscopic interference. Experimental results indicate that a two-step high pressure bomb acid digestion (1st step with HNO3+HClO4, and 2nd step with HF) procedure without evaporation is the optimum pre-treatment procedure for determining Cr by ICP-MS. In addition, laser ablation (LA) ICP-MS is used directly to analyze for Cr in airborne particulate matter. Results obtained by LA-ICP-MS correlate well with certified values and values obtained from the conventional acid digestion/HR-ICP-MS method. The detection limit for Cr in air particles by HR-ICP-MS with the proposed digestion method is

Determination of arsenic and vanadium in airborne related reference materials by inductively coupled plasma-mass spectrometry

Abstract This study investigated sample digestion techniques and instrumental interference in determining As and V in airborne related reference materials using inductively coupled plasma mass spectrometry (ICP–MS). Four reference materials, NIST SRM 1648 urban particulate matter, BCR Reference Material No. 176 city waste incineration ash, NIST SRM 2709 San Joaquin soil, and NIST SRM 1633b coal fly ash were dissolved by acid mixture high-pressure bomb digestion. A HNO3+H2O2+HF mixed acid digestion with a low temperature evaporation procedure is proposed as an effective sample pretreatment method for the determination of As in all samples. The addition of HF is required especially for dissolving geologically originated samples such as soil or dust. It was found that, with the proposed digestion procedure, the determinations of V are still unacceptable for highly chlorinated samples when using quadrupole ICP–MS. It was also proved that sector-field ICP–MS is sufficiently sensitive for the determination of V, and can be utilized as a valid tool to investigate the amount and direction of biased results obtained from ICP–MS.

Application of methods (sequential extraction procedures and high-pressure digestion method) to fly ash particles to determine the element constituents: A case study for BCR 176

Sequential extraction procedures and the high-pressure digestion method were selected to determine the element constituents of fly ash samples. Sequential extraction is one of the most useful methods used to measure the various elements from municipal solid waste incineration ash and contaminated soils. The extract from each step is analyzed using various techniques and equipment, and the results are then evaluated. In this work, a six-step extraction procedure modified from that of Tessier et al. and Wang et al. was performed and applied to the certified reference material BCR 176 (city waste incineration ash). Analyses were carried out by various techniques such as inductively coupled plasma atomic emission spectrometry (ICP-AES), inductively coupled plasma-mass spectrometry (ICP-MS), scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX), and X-ray powder diffraction (XRPD) to evaluate the characteristics of fly ash. The extraction efficiency of many elements was higher than 80%, and the relative standard deviations (RSD) for recovery of most elements were within 10%. In addition, an H(2)O(2)+HNO(3)+HF mixed acid digestion solution processed using a low-temperature evaporation procedure was selected as the optimal process for fly ash digestion. The results of this work provide information on the chemical composition, distribution, and potential mobility of the investigated elements.

Using dried-droplet laser ablation inductively coupled plasma mass spectrometry to quantify multiple elements in whole blood

This paper describes a simple procedure for the direct analysis and determination of multiple elements in dried blood samples on a filter membrane using laser ablation coupled with inductively coupled plasma mass spectrometry (LA-ICP-MS). With this technique, we simultaneously quantified 13 elements in whole blood: Be, Mn, Co, Ni, Tl, Bi, Sb, Pb, Cu, Zn, Ba, Mg, and Cd. The measured accuracies was in agreement with the Seronorm CRM certified values, except for Mn, Zn, Ba and Cd, which presented absolute differences higher than the expanded uncertainty for these elements. The within-run precision was less than 5.7% (relative standard deviation, RSD), except for the analyses of Be, and Mn (8.6% and 11.1%, respectively). The reproducibility (between-run precision) was calculated in terms of the RSD obtained for 12 analyses (i.e., four replicates of each sample in three analytical runs). Apart from Be, Mn, and Zn, the reproducibilities of all the elements listed above ranged between 4.0% and 8.5%. In contrast, for Cd, the concentration obtained was significantly different from the certified value; analyses of this element exhibited low reproducibility. Applying the matrix-matched calibration method, the accuracy for Cd measured was in agreement with both SRM966 and BCR 635; thus, matrix-matched calibration is a practical means of overcoming matrix-enhancement effects for the quantification of Cd. Sample throughput (ca. 5 min per sample) made it possible to rapidly screen a larger number of samples relative to other techniques that require time-consuming sample preparation steps (e.g., removal of a portion of the solid sample or digestion).

Analytical procedures on multi-element determinations of airborne particles for receptor model use

A multistage analytical procedure is developed in this investigation to determine 22 elements (Al, As, Ba, Ca, Cd, Cl, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, S, Sb, Si, Sr, Ti, V, and Zn) on loaded PTFE-filter samples of atmospheric-particulate matter collected by dichotomous samplers. It includes a direct X-ray fluorescence measurement followed by instrumental neutron activation analysis (INAA) or microwave acid digestion of the sample for spectroscopic analysis. ICP-MS was employed for elemental analysis after the digestion. A combination of different analytical methods and standard operational procedures were developed to meet the requirements for receptor model analysis. The quality assurance program includes the intercomparison with the use of alternative methods for accuracy and precision control.