Microwave-assisted extraction of rare earth elements from petroleum refining catalysts and ambient fine aerosols prior to inductively coupled plasma-mass spectrometry

Abstract

In the absence of a certified reference material, a robust microwave-assisted acid digestion procedure followed by inductively coupled plasma -mass spectrometry (ICP-MS) was developed to quantify rare earth elements (REEs) in fluidized-bed catalytic cracking (FCC) catalysts and atmospheric fine particulate matter (PM2.5). High temperature (200 °C), high pressure (200 psig), acid digestion (HNO3, HF, and H3BO3) with 20 minute dwell time effectively solubilized REEs from six fresh catalysts, a spent catalyst, and PM2.5. This method was also employed to measure 27 non-REEs including Na, Mg, Al, Si, K, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Zr, Mo, Cd, Cs, Ba, Pb, and U. Complete extraction of several REEs (Y, La, Ce, Pr, Nd, Tb, Dy, and Er) required HF indicating that they were closely associated with the aluminosilicate structure of the zeolite FCC catalysts. Internal standardization using 115In quantitatively corrected non-spectral interferences in the catalyst digestate matrix. Inter-laboratory comparison using ICP-optical emission spectroscopy (ICP-OES) and instrumental neutron activation https://ntrs.nasa.gov/search.jsp? R=20060022633 2018-05-10T22:17:43+00:00Z analysis (INAA) demonstrated the applicability of the newly developed analytical method for accurate analysis of REEs in FCC catalysts. The method developed for FCC catalysts was also successfully implemented to measure trace to ultra-trace concentrations of La, Ce, Pr, Nd, Sm, Gd, Eu, and Dy in ambient PM2.5 in an industrial area of Houston, TX. Analytical novelty of the research. We have developed and quantitatively verified microwave digestion and inductively coupled plasma -mass spectrometry techniques to accurately and precisely measure all naturally occurring rare earth elements in the aluminosilicate matrices of fluidized-bed catalytic cracking catalysts and atmospheric fine particles. One important basis of our research is that to date, no certified reference material is available for these zeolite-based catalysts. Additionally, existing reference materials for atmospheric particles such as SRM 1648 from the National institute of Standards and technology only include four rare earths (La, Ce, Sm, and Eu) and that too only as uncertified elements. were detected in PM 2.5 samples from Houston's Ship Channel area. We demonstrate that the loss of FCC catalyst from the refinery was the primary source of REEs in ambient atmospheric fine particles and that increase in PM 2.5 mass was predominantly caused by the loss of FCC catalyst during the "upset" event. U N I V E R S I T Y of H O U S T O NI appreciate the opportunity to publish in Analytica Chimica Acta. As the corresponding author, please contact me at chellam@uh.edu if I can provide additional information.Sincerely, Shankar Chellam Associate Professor Department of Civil and Environmental Engineering Department of Chemical EngineeringMicrowave-assisted extraction of rare earth elements from petroleum refining catalysts and ambient fine aerosols prior to inductive...

Trace elemental analysis of airborne particulate matter using dynamic reaction cell inductively coupled plasma – mass spectrometry: Application to monitoring episodic industrial emission events

“…All masses were thus fully centered during analyses. The following masses were measured: 23 Na, 24 Mg, 27 Al, 44 Ca, 49 Ti, 51 V, 52 Cr, 53 Cr, 55 Mn, 56 Fe, 57 Fe, 59 Co, 60 Ni, 65 Cu, 66 Zn, 68 Zn, and 115 In. Two isotopes for Cr, Fe and Zn were measured to double-check against polyatomic interferences: in all cases, mass ratios 52/53, 56/57, and 66/68, matched the accepted isotopic compositions of Cr, Fe and Zn, respectively, to within 5%.…”

“…Our previously developed two-stage microwave digestion (MARS 5, CEM Corp., Matthews, NC) procedure was employed for all samples [21,23]. In the first stage, the PM 10 sample along with 3 mL HNO 3 (14.3 M) and 10 L HF (48%) was heated to 200 • C at a pressure set point of 1.55 MPa (225 psig) for a dwell time of 20 min.…”

Bismuth dimercaptopropanol (BisBAL) inhibits the expression of extracellular polysaccharides and proteins by Brevundimonas diminuta: Implications for membrane microfiltration

“…Bi concentrations in several solutions were independently measured by inductively coupled plasma mass spectrometry (ICP-MS, Elan 6000, Perkin Elmer, Norwalk, CT) using our recently developed method (Kulkarni et al, 2007) as a quality control check to ensure accurate BisBAL dosing. For these measurements, the nebulizer gas flow, lens voltage, and RF power were first optimized to get the maximum Bi intensity and low oxide species formation.…”

Validation of a Simple Microwave-Assisted Acid Digestion Method Using Microvessels for Analysis of Trace Elements in Atmospheric PM2.5 in Monitoring and Fingerprinting Studies

“…Depending on the sample matrix and elements of interest, a large number of different combinations of mineral acids and oxidizing agents such as HNO 3 , HNO 3 /HCl, HNO 3 /HCl/HF, HNO 3 /HF/H 3 BO 3 , HNO 3 /HClO 4 , HNO 3 /H 2 O 2 have been used for microwave assisted acid digestions. For example, determination of platinum group elements in atmospheric aerosols requires the presence of HCl in the digestion mixture, or hydrofluoric acid is required to completely release the trace elements from the aluminosilicate matrix of PM [15,[22][23][24]. However, the presence of some digestion acids in the sample matrix aggravates the spectroscopic interferences in ICP-MS analysis by formation of species with m/z ratio that can not be resolved from that of the analyte of interest, and nonspectroscopic interferences related to the increased total dissolved solid (TDS) content in the solution [13,14,23].…”

“…For example, determination of platinum group elements in atmospheric aerosols requires the presence of HCl in the digestion mixture, or hydrofluoric acid is required to completely release the trace elements from the aluminosilicate matrix of PM [15,[22][23][24]. However, the presence of some digestion acids in the sample matrix aggravates the spectroscopic interferences in ICP-MS analysis by formation of species with m/z ratio that can not be resolved from that of the analyte of interest, and nonspectroscopic interferences related to the increased total dissolved solid (TDS) content in the solution [13,14,23]. Although recent developments, such as reaction/collision cell or high resolution sector field ICP-MS offer the analyst effective tools for suppressing matrix-induced interferences [16,25], selecting a suitable combination of the mineral acids and using the minimum amount of reagents remains critically important for achieving low detection limits and interference-free measurements in trace element analysis by ICP-MS.…”