In this paper the possibilities and restriction for applying the low power TXRF spectrometer PicoTAX for the one-site analysis of heavy metal contaminated soils and sediments are evaluated. Basis for ...this evaluation is the Superfund Innovative Technology Evaluation (SITE) program, conducted by the U.S. Environmental Protection Protection Agency (US EPA). During a measurement campaign, performed under realistic conditions, 320 soil and sediment samples were analyzed. The task was the fast analysis of the main target elements antimony, arsenic, cadmium, chromium, copper, iron, lead, mercury, nickel, selenium, silver, vanadium, and zinc. These elements were present in wide ranging concentrations.
Out of a set of seven primary and five secondary objectives the method detection limits, accuracy and precision of the TXRF measurements are discussed.
In addition to the on-site measurements, the application of TXRF analysis for the analysis of soil- and sediment samples after complete microwave assisted acid digestion is reported.
Recent instrument improvements have distinctly increased the quality of measurement results. A detailed description of these new developments and new measurement results are discussed
The uptake of inorganic nutrients by rootless parasitic plants, which depend on host connections for all nutrient supplies, is largely uncharted. Using X‐ray fluorescence spectroscopy (XRF), we ...analyzed the element composition of macro‐ and micronutrients at infection sites of the parasitic angiosperm Cuscuta reflexa growing on hosts of the genus Pelargonium. Imaging methods combining XRF with 2‐D or 3‐D (confocal) microscopy show that most of the measured elements are present at similar concentrations in the parasite compared to the host. However, calcium and strontium levels drop pronouncedly at the host/parasite interface, and manganese appears to accumulate in the host tissue surrounding the interface. Chlorine is present in the haustorium at similar levels as in the host tissue but is decreased in the stem of the parasite. Thus, our observations indicate a restricted uptake of calcium, strontium, manganese and chlorine by the parasite. Xylem‐mobile dyes, which can probe for xylem connectivity between host and parasite, provided evidence for an interspecies xylem flow, which in theory would be expected to carry all of the elements indiscriminately. We thus conclude that inorganic nutrient uptake by the parasite Cuscuta is regulated by specific selective barriers whose existence has evaded detection until now.
In clinical service laboratories, one of the most common analytical tasks with regard to inorganic traces is the determination of the nutrition-relevant elements Fe, Cu, Zn, and Se.
Because of the ...high numbers of samples and the commercial character of these analyses, a time-consuming sample preparation must be avoided.
In this presentation, the results of total reflection X-ray fluorescence measurements with a low-power system and different sample preparation procedures are compared with those derived from analysis with common methods like Atomic Absorption Spectroscopy (AAS) and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS).
The results of these investigations indicate that the optimal total reflection X-ray fluorescence analysis of the nutrition-relevant elements Fe, Cu, Zn, and Se can be performed by preparing whole blood and serum samples after dilution with ultrapure water and transferring 10 μl of internally standardized sample to an unsiliconized quartz glass sample carrier with subsequent drying in a laboratory oven. Suitable measurement time was found to be 600 s.
The enhanced sample preparation by means of microwave or open digestion, in parts combined with cold plasma ashing, led to an improvement of detection limits by a factor of 2 for serum samples while for whole blood samples an improvement was only observed for samples prepared by means of microwave digestion. As the matrix elements P, S, Cl, and for whole blood Fe have a major influence on the detection limits, most probably a further enhancement of analytical quality requires the removal of the organic matrix.
However, for the routine analysis of the nutrition-relevant elements, the dilution preparation was found to be sufficient.
Total reflection X-ray fluorescence (TXRF) analysis is an established technique for trace-element analysis in various types of samples. Though expensive large-scale systems restricted the ...applications in the past, in this study the capability of a benchtop system for trace elemental analysis is reported. The suitability of this system for the mobile on-site analysis of heavy metal contaminated soils and sediments is reported as well as the possibilities and restrictions of TXRF for additional applications, including trace-element analysis of water, glass and biological samples.
Metal/mineral dyshomeostasis has been implicated in the development of Alzheimer's disease (AD). The aim of the study was to investigate the difference in absolute and percentage levels of plasma ...phosphorus, calcium, iron, zinc, copper, selenium in cognitively normal (CN) and AD subjects. Total reflection X-ray fluorescence (TXRF) spectroscopy was used to detect plasma metals/minerals in CN and AD subjects (n = 44 per group). TXRF detected significantly increased plasma levels of phosphorus (p = 1.33 × 10
) and calcium (p = 0.025) in AD compared to CN subjects, with higher phosphorus/calcium (p = 2.55 × 10
) ratio in the former. Percentage concentrations calculated for phosphorus, calcium, iron, zinc, copper, selenium by dividing the concentration of each element by the total concentration of these elements and multiplying by 100%, demonstrated phosphorus was higher in AD compared to CN subjects, while calcium, iron, zinc, copper and selenium were lower in AD subjects, with area under the curves as high as 0.937 (p = 6 × 10
) computed from receiver operating curves. With exclusion of high levels of phosphorus and calcium from percentage calculations, iron levels remained low in AD whereas zinc was higher in AD, and copper and selenium levels were similar. We demonstrate altered distribution of elements in the plasma of AD subjects with high interdependencies between elemental levels and propose the potential of TXRF measurements for disease monitoring.
The aim of the present study was to explore impact of endurance exercise on urinary level of minerals and trace elements as well as on some oxidative stress and biochemical parameters. Urine samples ...were collected from participants (n=21) of mountain ultra-marathon race (53km; Medvednica, Zagreb, Croatia), before (baseline value), immediately after, 12h and 24h after the race. In urine samples level of minerals (Ca, P, K and Na) and trace elements (Se, Zn, Mn, Cu, Fe and Co) were assessed using the bench top Total reflection X-ray Fluorescence (TXRF) spectrometer. Oxidative stress was determined as level of malondialdehyde (MDA). Immediately after the race level of minerals, trace elements, MDA, creatinine, ketones, erythrocytes and specific gravity increased compared to their baseline value. In 24h follow-up trace elements involved in antioxidant defence, MDA and biochemical parameters returned to their baseline values, Cu and Co remained increased as after the race, Fe and K tended to return to baseline values while Ca, P and Na continued to increase. Mountain ultra-marathon resulted in alteration of physiologically important minerals and trace elements that for some minerals and trace elements persist, indicating their involvement in recovery processes. However, due to their loss in urine, level of minerals and trace elements in athletes participating in endurance exercise should be monitored.
Quantitative chemical analysis of airborne particulate matter (PM) is vital for the understanding of health effects in indoor and outdoor environments, as well as for enforcing EU air quality ...regulations. Typically, airborne particles are sampled over long time periods on filters, followed by lab-based analysis, e.g., with inductively coupled plasma mass spectrometry (ICP-MS). During the EURAMET EMPIR AEROMET project, cascade impactor aerosol sampling is combined for the first time with on-site total reflection X-ray fluorescence (TXRF) spectroscopy to develop a tool for quantifying particle element compositions within short time intervals and even on-site. This makes variations of aerosol chemistry observable with time resolution only a few hours and with good size resolution in the PM10 range. The study investigates the proof of principles of this methodological approach. Acrylic discs and silicon wafers are shown to be suitable impactor carriers with sufficiently smooth and clean surfaces, and a non-destructive elemental mass concentration measurement with a lower limit of detection around 10 pg/m3 could be achieved. We demonstrate the traceability of field TXRF measurements to a radiometrically calibrated TXRF reference, and the results from both analytical methods correspond satisfactorily.
Total Reflection X-Ray Fluorescence (TXRF) is a mature technique to evaluate quantitatively the elemental composition of liquid samples deposited on clean and well polished reflectors. In this paper ...the results of the first worldwide TXRF round-robin test of water samples, involving 18 laboratories in 10 countries are presented and discussed. The test was performed within the framework of the VAMAS project, interlaboratory comparison of TXRF spectroscopy for environmental analysis, whose aim is to develop guidelines and a standard methodology for biological and environmental analysis by means of the TXRF analytical technique.
•The discussion of the first worldwide TXRF round-robin test of water samples (18 laboratories of 10 countries) is reported.•Drinking, waste, and desalinated water samples were tested.•Data dispersion sources were identified: sample concentration, preparation, fitting procedure, and quantification.•The protocol for TXRF analysis of drinking water is proposed.
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