Speciation of Chromium in Alkaline Soil Extracts by an Ion-Pair Reversed Phase HPLC-ICP MS Method

Abstract

The aim of this work was to study by a hyphenated HPLC-ICP MS technique the chromium species released during alkaline extraction of various soils collected from a contaminated area of an old tannery. An ultrasound-assisted extraction procedure using 0.1 mol L−1 Na2CO3 solution was developed for the release of chromium species from the soil. The chromium species in the soil extracts were separated on a C8 column using EDTA and TBAH solution as a mobile phase. The use of an ICP-QQQ MS spectrometer in tandem mass configuration (MS/MS) combined with an octopole reaction system (ORS3) pressurized with helium allows one to eliminate spectral interferences during Cr determination in the soil extracts. The detection limit of the procedure was 0.08 µg L−1 for Cr(III) and 0.09 µg L−1 for Cr(VI) species. The trueness of the IP RP HPLC-ICP MS method was proved by an analysis of CRM 041 and CRM 060. The advantage of the proposed method is the analysis of soil extracts without their preliminary neutralization, which limits the losses of Cr(VI) due to the reduction process. The analysed soils mainly contained chromium in immobile forms (94.6–98.5% of the total Cr content). In all alkaline soil extracts mostly the Cr(VI) form was found, but in the extract of organic soils Cr(III) was also present. This arose from the reduction of Cr(VI) species by organic matter (humic acids) and Fe(II). The amount of formed Cr(III) species was dependent on the type of soil (content of organic matter, Mn and Fe) and its moistness. For the first time, the presence of neutral and non-polar chromium fractions in the soil extracts was also demonstrated. It was found that reliable speciation analysis results could be obtained for mineral soils.

Obtaining Granules from Waste Tannery Shavings and Mineral Additives by Wet Pulp Granulation

“…Inside this shaft is a rigid rod (4), which vibrates in the axial direction. Rectilinear, axial vibrations of the rod are forced by an electro vibrator (10). These vibrations are transferred to the granulator disc by the pusher (5) located in the axis of rotation of the disc inside the hollow shaft (2).…”

“…Large amounts of gaseous, liquid, and solid waste containing chromium compounds are discharged into the air, surface water, and soil, causing their contamination. By using a hyphenated HPLC-ICP MS (High-performance Liquid Chromatography coupled to Inductively Coupled Plasma Mass Spectrometry) technique, Leśniewksa et al [ 10 ] define the chromium species released during alkaline extraction of various soils collected from a contaminated area of an old tannery. In an analysis of the composition of tannery solid waste, anaerobic digestion has also been suggested as a potential alternative treatment [ 11 ].…”

Elemental Speciation Analysis in Environmental Studies: Latest Trends and Ecological Impact

“…The advantage of this method was related to the possibility of analyzing soil extracts directly, which limited the losses of Cr(VI) due to reduction processes. This approach did not report the use of appreciable amounts of strong acids and toxic organic solvents, which makes it an interesting study under the canons of Green Chemistry [79].…”

Atomic spectrometry update: review of advances in elemental speciation

“…No Cr species were detected in the water samples, but they were found in lettuce seedlings grown hydroponically and in extracts of simulated gastric and intestinal fluids of the plants. Leśniewska and Godlewska-Żyłkiewicz 95 made a thorough study of the performance of an ion-pair reversed phase HPLC-ICP-MS method for the determination of Cr III and Cr VI in alkaline (0.1 mol L −1 sodium carbonate) extracts of soils. The method replaces the quadrupole ICP-MS instrument of a previously published method with a triple quadrupole instrument.…”