An ultrasound‐assisted sample preparation method of carbonatite rock for determination of rare earth elements by inductively coupled plasma mass spectrometry

Abstract

Rationale A method for the determination of rare earth elements in carbonatite rocks by inductively coupled plasma mass spectrometry (ICP‐MS) was developed. Methods An alkaline rock, carbonatite, was submitted to ultrasound‐assisted extraction (USAE) using an ultrasound bath, a cup horn system or an ultrasound probe. The main USAE parameters were evaluated, such as extraction time (1 to 30 min), extraction temperature (20 to 100°C) and ultrasound amplitude (10 to 100%). For ICP‐MS, a desolvation system (APEX‐Q) was used to reduce interference in lanthanide determination. To evaluate if the effect of ultrasound improved extraction, experiments were carried out using magnetic stirring (500 rpm) for comparison. Results The temperature and ultrasound amplitude optimized for the method were 70°C and 40%, respectively, using dilute nitric acid (3% v/v). Quantitative analyte recoveries were obtained using an ultrasound bath (25 kHz/100 W) which allowed for the simultaneous extraction of twelve replicates. Conclusions All the results obtained with the use of ultrasound systems were better than those obtained with mechanical stirring. The extracts were suitable for ICP‐MS analysis and the results were in agreement with those obtained by the reference method (using wet acid digestion). Based on the results, the use of USAE can be considered an alternative method for sample preparation of carbonatite rocks, under milder conditions, for further ICP‐MS analysis.

The use of ultrasound in the South Cone region. Advances in organic and inorganic synthesis and in analytical methods

“…Subsequently, Gatiboni et al . from Universidade Federal de Santa Maria (Brazil) [83] carried out a method using a diluted solution of nitric acid to extract REE in carbonatite rocks. The results obtained showed that higher temperatures favored the cavitation effects.…”

“… The acoustic intensity is related to the acoustic pressure.-The ultrasound amplitude is related to the acoustic pressure [82] Rare earth elements Carbonatite rock UAE ES: % v/v HNO3 200 mg of carbonatite rock, sonicated (USB) 25 kHz/100 W, 15 min, 70 °C, 40% of ultrasound amplitude. Higher temperatures favoured the cavitation effect, decrease in the surface tension, – increase in the vapor pressure of the liquid [83] Cd Herbal medicine UAE ES: supramolecular solvent Digestion solvent: HNO3 210.0 mg Ginkgo biloba L. leaf powder, 20.0 min (USB, UNIQUE RS 1600) with 25.0 mL of 0.10 mol L −1 HNO3. Supramolecular solvent-based microextraction procedure.…”

Determination of Rare Earth Elements by Inductively Coupled Plasma–Tandem Quadrupole Mass Spectrometry With Nitrous Oxide as the Reaction Gas

“…However, the accuracy and the precision of an analytical result may be greatly deteriorated in case of a relatively large portion (for example, over 30%) of spectral interference being corrected due to the variance in the signal intensity of the interfering spectrum. The second one is suppressing the formation of an interfering polyatomic ion by removing an interferent element (for example, Ba) from REEs through chemical separation ( Watanabe et al, 2018 ; Ito et al, 2019 ; Barrat et al, 2020 ; Bradley et al, 2020 ) or by using a desolvating device to remove water contents introduced into the argon plasma (to suppress the formation of solvent related ions, for example, O + , H + , and OH + ) ( Giardi et al, 2018 ; Gatiboni et al, 2020 ; Shen et al, 2022 ). The third one is separating an interfering polyatomic ion from an REE of interest by high-resolution ICP-MS ( Giardi et al, 2018 ; Barrat et al, 2020 ; Bradley et al, 2020 ; Kiruba et al, 2021 ), collision/reaction cell ICP-MS ( Gueguen et al, 2009 ; Arslan et al, 2018 ; Rojano et al, 2019 ; Trommetter et al, 2020 ; Baghaliannejad et al, 2021 ), and tandem quadrupole ICP-MS with a reaction cell (ICP-QMS/QMS) ( Galusha et al, 2018 ; Zhang et al, 2019 ; Zhu, 2020 ; Zhu et al, 2021 ).…”

Ultrasound-assisted conversion of tannic acid to gallic acid as a strategy to obtain value-added products

“…Ultrasound (US) has been applied for many processes, including removal of contaminants, synthesis and extraction from several feedstocks [19] , [20] , [21] . Ultrasound (ranging from 0.3 to 1 MHz) has been used to develop protocols to convert tannic acid into ellagic acid crystals with no reagent addition [22] .…”