Mercury Determination in Natural Zeolites by Thermal Decomposition Atomic Absorption Spectrometry: Method Validation in Compliance with Requirements for Use as Dietary Supplements

Șenilă, Marin; Cadar, Oana; Șenilă, Lăcrimioara; Hoaghia, Alexandra; Miu, Ion

doi:10.3390/molecules24224023

Cited by 22 publications

(20 citation statements)

References 34 publications

(38 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A possible explanation could be the purification effect of HCl by solubilization of mineral impurities from the quartz crystal lattice structure [26,28]. Arcoya et al reported a decrease of the characteristic peaks by HCl treatment, however our results show no modification of the characteristic peak intensities, probably due to the stability of crystal structure [26,29]. Our results are in line with those of Kavak et al, who reported that the characteristic peak intensities of clinoptilolite in the control sample were nearly the same as those of samples exposed to gastric fluids [19].…”

Section: Structure Of the Zeolitescontrasting

confidence: 78%

“…The contents of Al, Fe, Ca, Mg, K, Na, Mn, and Ti in RZ and TZ samples were determined using a S1 Titan 800 X-ray fluorescence spectrometer (Bruker, Berlin, Germany). The conversion to the corresponding oxide was made by multiplying the element concentration with 1.8895 (Al 2 O 3 ), 1.4297 (Fe 2 O 3 ), 1.3392 (CaO), 1.6583 (MgO), 1.2046 (K 2 O), 1.3480 (Na 2 O), 1.2912 (MnO), and 1.6683 (TiO 2 ) [29]. The SiO 2 and loss of ignition (LOI) were determined by gravimetry [38].…”

Section: Characterizationmentioning

confidence: 99%

See 1 more Smart Citation

Effects of Thermal Treatment on Natural Clinoptilolite-Rich Zeolite Behavior in Simulated Biological Fluids

et al. 2020

View full text Add to dashboard Cite

This study presents the effect of thermal treatment (450, 500, 600, 750, and 800 °C) on a Romanian clinoptilolite-rich natural zeolite, along with the interaction of raw and thermally treated zeolites with simulated gastric fluid (SGF, pH = 1.20) at different zeolite to SGF ratios and exposure times. The zeolites were characterized using gravimetric analysis, X-ray fluorescence, powder X-ray diffraction (pXRD), and Fourier transform infrared (FT-IR) spectroscopy. The chemical composition of the zeolite subjected to thermal treatment did not change significantly with the increase of temperature. Structural changes were not detectable by pXRD and FT-IR analyses in the zeolites thermally treated up to 500 °C, while above 600 °C a gradual structural breakdown of zeolite was noticed. At high temperatures, the broad, low-intensity peaks in pXRD patterns indicated the partial amorphization of the crystalline structure. The pXRD and FT-IR analyses showed that the crystalline structure of zeolites remains unaffected after their exposure to SGF. The results revealed that the amounts of Fe, Na, Mg, K, Ca, Al, and Si released depends mainly on the zeolite to SGF ratio, and to a lower extent on the thermal treatment temperature, while the exposure time of 1 to 7 days does not have a significant impact on the elements released in SGF.

show abstract

Section: Structure Of the Zeolitescontrasting

confidence: 78%

Section: Characterizationmentioning

confidence: 99%

Effects of Thermal Treatment on Natural Clinoptilolite-Rich Zeolite Behavior in Simulated Biological Fluids

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Microwave digestion of a 0.5 g powder of sample using microwave-assisted acid digestion using a microwave system (Berghof, Eningen, Germany) was described elsewhere [31]. The heating program of the microwave system for samples digestion comprised three steps of heating at 160 • C, 200 • C, the cooling at 100 • C, in a total time of digestion of 35 min.…”

Section: Instrumentation and Methodsmentioning

confidence: 99%

“…Beside these, other non-conventional techniques can also be used to determine metal analytes in different samples [28][29][30]. For specific elements (i.e., Hg) which have high volatility, the direct measurement in solid samples (including zeolites) by thermal desorption is possible [31].…”

Section: Introductionmentioning

confidence: 99%

Development and Validation of a Spectrometric Method for Cd and Pb Determination in Zeolites and Safety Evaluation

Șenilă

Cadar

Miu³

2020

Molecules

View full text Add to dashboard Cite

An analytical method based on microwave-assisted acid digestion and atomic absorption spectrometry with graphite furnace as atomization source was developed and validated for determining trace elements (Cd and Pb) in zeolites used as dietary supplements, for their characterization and safety evaluation. The method was checked for the main performance parameters according to the legislation requirements in the field of dietary supplements. In all cases, the obtained performance parameters were satisfactory. The selectivity study showed no significant non-spectral matrix effect. The linearity study was conducted for the calibration curves in the range of 0–10 ng mL−1 for Cd and 0–30 ng mL−1 for Pb. The obtained limits of detection (LoDs) and the limits of quantification (LoQs) were sufficiently low in order to allow Pb and Cd determination in dietary supplements. For the internal quality control, certified reference materials were analysed and good recoveries were obtained. The precision study was performed in terms of repeatability and reproducibility, considering the requirements imposed by the Commission Decision (2007/333/EC) and the method fulfilled these performance parameters. Expanded measurement uncertainties were estimated to 11% for Cd and 10% for Pb. Cd and Pb content were measured in real zeolite samples and, using these data, a safety evaluation was carried out.

show abstract

“…The direct determination of chemical vapor-generating elements by avoiding derivatization was also attempted. Therefore, mercury determination by thermal decomposition atomic absorption spectrometry (TD-AAS) [ 37 , 38 ], liquid/solid sampling with electrothermal vaporization (ETV) in GFAAS [ 39 , 40 , 41 ], or the emergent HR-CS-ETAAS using Xe lamp [ 42 , 43 ] were successfully applied. At the same time, ICP OES [ 44 ] and ICP-MS [ 45 , 46 ] using pneumatic and ultrasonic nebulization, or solid sampling by laser ablation (LA-ICP-MS) [ 47 ] and LIBS OES [ 48 ] provide simultaneous direct determination without derivatization.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Determination of As, Bi, Sb, Se, Te, Hg, Pb and Sn by Small-Sized Electrothermal Vaporization Capacitively Coupled Plasma Microtorch Optical Emission Spectrometry Using Direct Liquid Microsampling

et al. 2021

View full text Add to dashboard Cite

The simultaneous determination of chemical vapor-generating elements involving derivatization is difficult even by inductively coupled plasma optical emission spectrometry or mass spectrometry. This study proposes a new direct liquid microsampling method for the simultaneous determination of As, Bi, Se, Te, Hg, Pb, and Sn, using a fully miniaturized set-up based on electrothermal vaporization capacitively coupled plasma microtorch optical emission spectrometry. The method is cost-effective, free from non-spectral interference, and easy to run by avoiding derivatization. The method involves the vaporization of analytes from the 10 µL sample and recording of episodic spectra generated in low-power (15 W) and low-Ar consumption (150 mL min−1) plasma microtorch interfaced with low-resolution microspectrometers. Selective vaporization at 1300 °C ensured the avoidance of non-spectral effects and allowed the use of external calibration. Several spectral lines for each element even in the range 180–210 nm could be selected. Generally, this spectral range is examined with large-scale instrumentation. Even in the absence of derivatization, the obtained detection limits were low (0.02–0.75 mg kg−1) and allowed analysis of environmental samples, such as cave and river sediments. The recovery was in the range of 86–116%, and the accuracy was better than 10%. The method is of general interest and could be implemented on any miniaturized or classical laboratory spectrometric instrumentation.

show abstract

Mercury Determination in Natural Zeolites by Thermal Decomposition Atomic Absorption Spectrometry: Method Validation in Compliance with Requirements for Use as Dietary Supplements

Cited by 22 publications

References 34 publications

Effects of Thermal Treatment on Natural Clinoptilolite-Rich Zeolite Behavior in Simulated Biological Fluids

Effects of Thermal Treatment on Natural Clinoptilolite-Rich Zeolite Behavior in Simulated Biological Fluids

Development and Validation of a Spectrometric Method for Cd and Pb Determination in Zeolites and Safety Evaluation

Simultaneous Determination of As, Bi, Sb, Se, Te, Hg, Pb and Sn by Small-Sized Electrothermal Vaporization Capacitively Coupled Plasma Microtorch Optical Emission Spectrometry Using Direct Liquid Microsampling

Contact Info

Product

Resources

About