A rapid microwave-assisted acid extraction method based on the use of diluted HNO3-H2O2followed by ICP-MS analysis for simultaneous determination of trace elements in coal samples

Mketo, Nomvano; Nomngongo, Philiswa N.; Ngila, Jane Catherine

doi:10.1080/03067319.2015.1025226

Cited by 16 publications

(12 citation statements)

References 42 publications

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“…Additionally, Ba and Sr concentration results show that, these two metals were most dominating across the whole spectrum of the three coal samples. It is also worthy to mention that, the sum concentration of most of the investigated metal ions correlated well with the concentration levels that were previous reported using total digestion methods 26,27 . This correlation confirms that, the accuracy and reliability of the proposed MW-ASE method was excellent.…”

Section: Instrumentation the Proposed Sequential Extraction Methods Wsupporting

confidence: 86%

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An improved microwave assisted sequential extraction method followed by spectrometric analysis for metal distribution determination in South African coal samples

Mketo

Nomngongo

2020

Sci Rep

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Some metal pollutants are corrosive in nature, are associated with fouling and slagging challenges of the coal boilers, are highly volatile and might cause air pollution and are catalyst poisoners during Fischer–Tropsch catalytic reaction. Therefore, this work describes an improved microwave-assisted sequential extraction (MW-ASE) method followed by ICP-OES/MS analysis for metal distribution determination in South African coal samples. The multivariate optimum conditions for each sequential step were 0.1 g, 200 °C and 5 min for sample amount, microwave temperature and extraction time, respectively. Under the optimum conditions, Ga, Sr and Ba were the only metals that showed solubility towards water, therefore, these metals are classified as highly mobile and eco-toxic under wet environmental conditions. Additionally, all the investigated metals showed solubility towards acidic conditions (HCl and HNO3). These results suggest that, most metal ions are predominantly bonded to sulphate, sulphide, and carbonate coal minerals. Alternatively, Ce, Cr and Y showed total extraction recoveries of ≤ 90%, confirming their strong affinity towards quartz coal minerals. In overall, the proposed MW-ASE method reported short extraction time (0.34 h), environmentally friendly reagents (H2O and diluted H2O2) and rapid multivariate optimization with acceptable extraction efficiencies (79–98%) and reproducibility (RSD ≤ 5%).

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Section: Instrumentation the Proposed Sequential Extraction Methods Wsupporting

confidence: 86%

“…One Touch Technology Microwave lab station (CEM Microwave Technology Ltd., North Caroline, USA) that was described in our research group 27 .…”

Section: Instrumentation the Proposed Sequential Extraction Methods Wmentioning

confidence: 99%

An improved microwave assisted sequential extraction method followed by spectrometric analysis for metal distribution determination in South African coal samples

Mketo

Nomngongo

2020

Sci Rep

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“…For all elements, the obtained recoveries were between 91 and 106 %, which confirms that the accuracy of the method is within 10 %. Using the described procedure an accurate results were obtained also for the elements like As, Se or Ni for which the use of collision/reaction cell [7,21,26] or mathematical corrections [37] are needed when using Q-ICP-MS.…”

Section: Trueness and Precisionmentioning

confidence: 99%

“…In the ICP-MS analysis of coal and coal ashes, several elements like Si, P, S, K, Ca, Fe and Cl origination from sample matrix or the employment of acids being used in sample dissolution process are problematic as they serve as precursors for the formation of polyatomic ions [15,16,24,26,36,50] which can be problematic to be handled with especially with commonly used quadrupole mass spectrometers with low-resolution [7,21,26,27,37]. The collision/reaction cell ICP-MS is an effective correction technique to minimize the interferences on the analyte of interest for conventional quadrupole ICP-MS [7,21,26,27]. While a decrease of the multi-element capabilities could be observed for older Q-ICP-MS systems, this problem has been dealt with for modern quadrupole ICP-MS instruments.…”

Section: Introductionmentioning

confidence: 99%

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Simultaneous Determination of 11 Elements in Fly Ash by Inductively Coupled Plasma Orthogonal Acceleration Time-of-Flight Mass Spectrometry After Closed-Vessel Microwave-Assisted Extraction with Ammonium Fluoride

et al. 2018

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A method for simultaneous multi-element analysis of fly ash samples by inductively coupled plasma orthogonal acceleration time-of-flight mass spectrometry (oaTOF-ICP-MS) after closedvessel microwave extraction with ammonium fluoride was introduced here. Corrosive and and/or toxic acids like HF, HCl or HClO 4 , as well as HNO 3 , which are commonly used during sample preparation of the fly ash samples are avoided in this method. The spectral effects due to the formation of different Cl, Na, K, Ca, Mg, containing polyatomic species interfering the determination of number of elements like As, Se or Ni during the oaTOF-ICP-MS analysis are negligible. Under the optimum experimental extraction conditions evaluated using a fractional factorial design being 10 mg of the sample extracted with 5 mL of 140 g L −1 NH 4 F for 10 min at 200 °C, subsequent analysis of the resulting supernatant enabled under optimum instrumental conditions and with Rh as an internal standard precise and accurate simultaneous determination 2 of 11 elements (Li, Be, Ni, As, Se, Rb, Sb, Cs, W, Tl and U) at trace and ultra-trace levels. The accuracy was assessed by analysing two certified reference materials, namely Fine Fly Ash CTA-FFA-1 and Constituent Elements in Coal Fly Ash Standard Reference Material ® 1633b. The precision of the reported method was better than 10 %.

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Determination of Major, Minor, and Toxic Elements in Tropical Fruits by ICP-OES After Different Microwave Acid Digestion Methods

Karasakal

2020

Food Anal. Methods

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A rapid microwave-assisted acid extraction method based on the use of diluted HNO₃-H₂O₂followed by ICP-MS analysis for simultaneous determination of trace elements in coal samples

Cited by 16 publications

References 42 publications

An improved microwave assisted sequential extraction method followed by spectrometric analysis for metal distribution determination in South African coal samples

An improved microwave assisted sequential extraction method followed by spectrometric analysis for metal distribution determination in South African coal samples

Simultaneous Determination of 11 Elements in Fly Ash by Inductively Coupled Plasma Orthogonal Acceleration Time-of-Flight Mass Spectrometry After Closed-Vessel Microwave-Assisted Extraction with Ammonium Fluoride

Determination of Major, Minor, and Toxic Elements in Tropical Fruits by ICP-OES After Different Microwave Acid Digestion Methods

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