Subproject 23

Determination of organic compounds in tailings

The general objective of subproject 23 is the qualitative and quantitative determination of organic compounds in soil and tailings samples collected in the areas where the BI, B IV and B IV-A dams were located and adjacent tailings spreading areas in the sub-basin of Ferro-Carvão stream, in Brumadinho, Minas Gerais. The compounds to be analyzed are those provided for in CONAMA Resolution 420/20096, which includes a total of 67 analytes. The analyzed samples will be collected according to the sampling plan contained in the Induced Internal Public Call No. 08/2020 (Collection of soil and tailings samples in the ferro-coal stream sub-basin).

It is part of the specific objectives of the subproject:

• Qualitatively and quantitatively analyze the organic compounds provided for in CONAMA Standard 420/20096 in all soil and tailings samples sent for analysis by the CTC-UFMG using liquid chromatography techniques coupled to sequential mass spectrometry (UHPLC-2D-MS/MS) and gas chromatography coupled with mass spectrometry (GC-MS and GC-MS/MS). These analyzes will be performed using validated methodologies according to the parameters recommended in the INMETRO validation guide;

• Carry out screening analyzes on all soil and tailings samples sent to the CTC-UFMG, in order to qualitatively and, if possible, quantitatively determine toxic organic contaminants that are not covered by the CONAMA Standard 420/2009. These analyzes will be performed using the technique of liquid chromatography coupled with high resolution mass spectrometry (UHPLC-HRMS);

• After the delivery of the partial reports foreseen as one of the products of this Call and the receipt of the georeferencing of the samples, provided by the CTC-UFMG, use graphics and statistical methods to interpret the data obtained, together with the results from other subprojects within the scope of the Brumadinho-UFMG Project, namely: Call 17+19, Call 14 and Call 12. These interpretations will be made in cases where these subprojects have already been completed, seeking relationships between the results of these calls that may indicate sources of compounds, if found , in tailings, soils, water resources and atmosphere;

• Establish correlations of similarities through the use of chemometric tools, such as PCA (Principal Component Analysis) and HCA (Hierarchical Clustering Analysis), seeking to trace similarity profiles and distribution patterns of organic compounds from tailings and soils collected where the dams were located BI, B IV and B IV-A and adjacent spreading areas in the Ferro-Carvão stream sub-basin;

• Discuss the results obtained taking into account relevant state and/or federal standards, data and information available on the Brumadinho-UFMG Platform and scientific databases. In other words, check whether the levels of possibly detected analytes are below current regulations. If not, try to find the causes of the anomaly. The results obtained in this notice may be correlated with those obtained in analogous notices, for example, in the detection of organic analytes in ground and surface water and, mainly, in sediments. A study showing the correlation of results obtained in such samples may reveal the amplitude and dynamics of contamination by such analytes. The results with organic analytes can be correlated with the levels of metals found in the same samples, possibly revealing specific interactions between metals and organic analytes;

• Evaluate the results obtained within the scope of the work carried out by the parties involved in the lawsuits that are being processed before the Court of the 2nd Public Finance Court of the Judicial District of Belo Horizonte, in addition to other available environmental monitoring works and scientific studies;

• Prepare a complete report using this data and comparisons with data from other works.

Methodological steps

1st Step: Sample collection;

2nd Step: Extraction of organic compounds from tailings samples;

3rd Step: Analysis of organic compounds through Solid Phase Extraction (SPE, Solid Phase Extraction) and Headspace Extraction (HS);

4th Step: Analysis by gas chromatography coupled with mass spectrometry (GC-MS and GC-MS/MS);

5th Step: Analyzes by liquid chromatography coupled to mass spectrometry (UHPLC-HRMS and UHPLC-2D-MS/MS) through Target Analyzes (UHPLC-2D-MS/MS) and Untarget Analyzes (UHPLC-HRMS);

6th Step: Data treatment through Univariate Analysis, Multivariate Analysis and Correlation of results with those from other similar subprojects within the scope of the Brumadinho-UFMG Project.

Meet the Team!!

Subproject Timeline 23