Development of a microwave-assisted ultraviolet digestion method for biodiesel and subsequent trace elements determination by SF-ICP-MS

Abstract

A microwave-assisted ultraviolet digestion (MW-UV) method for biodiesel is proposed for subsequent determination of Ba, Co, Cr, Cu, Mn, Ni, Pb, Sr, and V by sector field inductively coupled plasma mass spectrometry (SF-ICP-MS).

Microwave-assisted hydrogen peroxide digestion followed by ICP-OES for determination of metals in selected fuel oils

“… SRM 1634c MA-HPD Ba, Na, Ni and V 9 mL of 5 M H 2 O 2 and 1 mL of conc. HNO 3 0.55–58.86 104.8–117.7 ≤ 4.1 0.046, 0.0304,0.408 and 0.057 ICP-OES This work Biodiesel MAAD Ba, Ni and V 10 mL of 7 M HNO 3 0.0027–0.101 95–108 < 6 0.00012,0.0028 and 0.00012 SF-ICP-MS 20 Crude oil MAAD Mg, Pb and Sr 6 mL of 14.4 M of HNO 3 Mg (12.5–201), Pb (0.09–0.203) and Sr (2.3–6.06) 95–104 < 4.0 0.1,0.3 and 0.07 MI-ICP-MS 36 Crude oil MAAD Na, Ca and Mg 4 M of H 2 O 2 and 5 mL conc. HNO 3 0.003–22.6 94–110 < 5 0.001–0.002 ICP-OES 5 Crude oil MAAD Ni and V 5 mL of 4 M H 2 O 2 and 10 mL of 5 M HNO 3 2–230 94.6–98.2 < 4.62 0.237 and 0.060 ICP-OES 37 Diesel MAAD Al, Cu, Fe, Ni and Ni 4 mL conc.…”

“…However, when comparing the reagents used, the current study used a much environmentally friendly method as the 1 mL concentrated acid when put in the reagent solution was much dilute (1.58 M). Another study reported by Barela et al 20 on the digestion of biodiesel for determination of Ba, Co, Cr, Mn, Ni, Pb, Sr and V prior to analysis using SF-ICP-MS. This method reported very good accuracy (95–108%), precision (< 6%), and MDL (0.12, 2.8 and 0.12 ng/g) for Ba, Ni and V respectively.…”

“…During univariate optimisation a single parameter is optimised at a time while keeping the other parameters constant 19 . In contrast, multivariate optimization investigates several parameters simultaneously and this helps to save time and reduce reagents used as less experiments are conducted in comparison to univariate 20 , 21 . The two-level full factorial was used for screening and the central composite design was used for response surface methodologies (RSM).…”

“…Additionally, multivariate in microwave assisted digestion was also reported by Barela et al . 20 , where a two-level full factorial was only used to optimize for [HNO 3 ] and [H 2 O 2 ] prior to analysis Ba, Co, Cr, Cu, Mn, Ni, Pb, Sr and V in biodiesel samples using Sector Field Inductively Coupled Plasma Spectrometry (SF-ICP-MS). The expression for a full factorial is 2 n , where n is the number of parameters to be optimized.…”