Samenvatting Environmental Analysis
1 Chapter 1: Sample preparation
1.1 Examples
1.1.1 Re-use of treated wastewater for irrigation & groundwater
recharge
Environmental Impacts and Public Perception:
à Water scarcity challenge: Not enough water for irrigation.
à Domestic wastewater collected → sent to Wastewater Treatment Plant (WWTP) à e6luent reused
à Applications of treated wastewater: -Agricultural use: Irrigation of crops.
-Land application: Soil/plant growth.
-Groundwater recharge: Use for irrigation.
à Monitoring required: Continuous water quality monitoring. + Policy relevance
1.1.2 Hauts -de-France heaps (SH)
Study focus: Leaching impact of slag heaps. à Cultural value: UNESCO World Heritage site.
à Environmental aspect: Located Sensitive Natural Areas → fragile ecosystems.
1.1.3 Per- and Polyfluoralkyl Substances
3M scandal (Belgium, 2021): Large amounts of PFOS (perfluorooctanesulfonic acid) and PFOA (perfluorooctanoic acid) discovered
in 2018. Found near the 3M site (produced until 2002). Linked to excavation works for the Oosterweel link project.
What = PFAS? Synthetic industrial chemicals, Structure: Hydrophobic carbon chain (fluorine atoms) + hydrophilic functional group.
à Risks: Persistent in environment (“forever chemicals”). Harmful human & animal health.
1.2 Environmental analysis and monitoring: chain of actions
1) Policy Question: Defines what to monitor, why, and for whom.
2) Design & Planning: Select indicators/parameters (chemical,
physical, biological). Decide on sampling locations, frequency, duration.
Choose methods (in situ measurements. lab-based vs. In situ sampling).
3)Sampling: Collect representative samples from the environment.
Minimize contamination or alteration during collection.
4)Sample Handling & Storage: Label and document properly for traceability. Preserve
samples (temperature, chemical preservatives, darkness).
5)Transport: Deliver samples to the lab without changes to composition.
6)In Situ Measurement & Sampling: On-site measurements (pH, temperature, dissolved oxygen, noise, radiation).
Advantages: real-time data, fewer sample alterations.
7)Analysis: Lab methods using instrumental, chemical, biological methods, ensure accuracy, precision, detection limits, QC
8)Data Treatment & Interpretation: Raw data must be processed and cleaned (calibration, error checks, statistical treatment).
Results are compared to standards, thresholds, or baseline values. Final output answer original policy/management question.
1.3 Fundamentals of sample preparation for environmental analysis
Purpose: Direct injection rarely possible: Environmental samples require pretreatment before analysis. (Time-consuming)
à Main roles: -Homogenize sample / remove moisture → air/freeze drying, grinding, sieving.
-Adjust analyte concentration → pre-concentration (trace analysis) or dilution (high contamination).
-Remove interferences → extraction, purification.
-Change sample phase → adapt to instrument (e.g., liquid for HPLC, gas GC).
-Liberate analyte from matrix → e.g., digestion, solid-phase extraction.
-Modify chemical structure → derivatization for better detection (HPLC/GC).
When Preparation is Needed (and When Not): Not always required: e.g., drinking water, some freshwater samples (ICP-MS
sensitivity su6icient). Highly demanding: → very time-consuming.
Categories of Metal Analysis Preparation:
à Metals in dissolved phase: Filtration & Extraction / pre-concentration (for total analysis or speciation, chromatography)
à Metals particulate/solid phase: Digestion(total digestion or selective extractions)&Chromatographic extraction speciati
, Forms of Metals in Aqueous Samples:
-Dissolved metals: Hydrated ions, complexes, colloids. Operational definition: pass
through 0.45 µm filter (unacidified sample).
-Suspended metals: Bound to oxides (Fe–Mn, Ca), silicates, or organic matter. Defined as
metals retained on 0.45 µm filter (acidified sample).
-Total metals: Metals unfiltered sample after acid digestion =dissolved + suspended fraction
Filtration in field to avoid changes: à Small volumes → syringe + filter. à Large volumes → vacuum or pressure filtration.
à Pressure filtration: for anoxic samples, using inert gas to prevent oxidation.
1.4 On site filtration (for dissolved trace metals)
Prevents changes in dissolved/particulate phases after sampling.
à Methods: Disposable filters (0.45 µm or 0.2 µm) → field use, small volumes. Vacuum or pressure
filtration → larger volumes, lab-based. Acidify immediately after filtration.
à Partitioning: Partition coe6icient: Kd = Mp]/[Md]
[Mp] = particulate metal concentration & [Md] = dissolved metal concentration
logKd = a6inity of metals for particulate vs. dissolved phase.
Extraction & Pre-Concentration (aqueous samples):
Why? Low concentrations (e.g., Ra) & Matrix interferences (e.g., salts in seawater → ICP-MS issues).
Methods: -Liquid-liquid extraction (LLE): Complexation of metals (e.g., ADDC, DDDC, pH 4).
Extract complexes into organic solvent (e.g., freon), back-extract with acid.
-Solid-phase extraction (SPE): Complexation with dithiocarbamate: C18 cartridges (organic complexes).
Chelating resin columns (e.g., Chelex 100, MnO₂ for Ra).
Procedure SPE: 1) Cartridge Selection: Chose sorbent (reverse or normal phase, ion exchange,) depend sample & analyte.
2) Conditioning: Rinse sorbent with solvent to activate/prepare the surface.
3) Sample Loading: Ensure matrix compatibility , analytes bind to sorbent phase
4) Washing: Pass solvent (usually same as sample matrix) to remove unretained/unwanted components.
5) Elution: Minimal solvent to release analytes, leaves impurities behind. Collect the eluate à analysis
1.5 Solid Samples: Metal Speciation & Extractions
à Importance of Speciation: Metals in solids exist in dieerent forms (speciation).
Speciation matters for toxicity, bioavailability, and mobility.
à Approaches: -Total extractions → complete dissolution.
-Selective extractions → extract labile/available forms.
-Sequential extractions → successive steps to assess partitioning.
1) Total Extractions (Acid Digestion): Acid choice depends on matrix:
(a) Clean / easily oxidizable → HNO₃ (b) Di6icult organic matter → HNO₃–HClO₄
(c) Sediments → HNO₃–HCl–HF (complete digestion) or HCl–HNO₃ (aqua regia) = pseudo-total digestion
(f) Biological samples → HNO₃–H₂O₂
Why HNO₃ is widely used? -Dual role: Acid + oxidizing agent. Dissolves oxides (e.g., CaO + H₃O⁺à Ca2+ +3H2O). Oxidizes zero-
valence metals (e.g., Fe, Cu → ions).
-Does not form insoluble salts, unlike HCl or H₂SO₄.
Digestion Methods:
-Hotplate digestion → under fume hood. Required to liberate analyte from sample matrix.
-Microwave-assisted digestion → faster, better control.
2) Selective Extractions: Goal: extract specific fractions of metals for determining trace metal partitioning, mobility &
bioavailability. No method isolates only one phase → results are operationally defined.
à Common reagents & fractions: -Acetic acid → dissolved, weakly bound, carbonate fraction.
-EDTA → complexable fraction. -HCl (1M) → acid volatile sulfides (AVS) + associated trace metals.
-AVS > trace metals → non-toxic. -AVS < trace metals → bioavailable = toxic risk.
-HNO₃ or HNO₃/H₂O₂ → anthropogenic/acid extractable metals
, 3) Sequential Extractions: Successive extractions → reveal partitioning and stability. à BCR Protocol
: 1 → Exchangeable ions & Carbonate/Phosphate-Bound Metals (Ca²⁺, Fe²⁺) Reagent: acetic acid (0.11M).
2 → Reducible metals. Reagent: NH₂OH·HCl (0.1 M) in HNO₃ (pH 2).
3 → oxidizable metals (sulphidic & organic bound). Reagent:H₂O₂ (8.8 M), applied twice. Followed NH₄Ac/HOAc (pH 5).
4 → residual fraction. Reagent: HF/HNO₃. Target: Refractory carbon, sulfides, silicates → strongly bound, not bioavailable
Certified Reference Materials (CRM): Provide true values of analytes for some environmental matrices.
à Uses: -Verify analytical methods. -Quality control in total, partial, or sequential extractions.
à QC in selective extractions → spike additions.
1.6 Enrichment factor (EF)
Purpose: Compare "natural" vs. "polluted" concentration levels of elements/compounds.
Formula: EF = (X/Alsample)/(X/Alreference) X = element concentration, Al = reference element (stable, crustal origin)
Interpretation of EF values: EF < 2 → Deficiency to minimal enrichment 2 < EF < 5 → Moderate enrichment
5 < EF < 20 → Significant enrichment 20 < EF < 40 → Very high enrichment
EF > 40 → Extremely high enrichment
1.7 In situ sampling (in situ measurements)
Direct field measurements without transporting samples
Common Parameters & Instruments: -pH → pH electrode -Temperature → Thermometer
-Turbidity → Turbidity sensor/meter -Conductivity → Conductivity meter -Dissolved oxygen → O₂ electrode
-Specific ions (F⁻, S²⁻) → Ion-selective electrodes -Trace elements → Passive sampler technique
-Small-scale portable instruments →portable XRF, Hg analyser detection limits important
2 Chapter 2: In situ measurements by passive sampling techniques
Why Passive Sampling? àSpot sampling = instantaneous values → may miss short-term variations
à Increasing sampling frequency or using automatic samplers improves accuracy
àPassive samplers = time-integrated pollutant levels
à Principle: dieusion through barrier or permeation through membrane
à Limitation: consumable cost can be high
Types of Passive Sampling Techniques:
1. Non-polar organic contaminants (partition/absorption): SPMD, MESCO, SPME, Chemcatcher & DGT
2. Polar organic contaminants (adsorption):POCIS, Chemcatcher & DGT
3. Metals (chelating or other mechanisms): DGT
2.1 Non-polar organic contaminants (partition/absorption)
2.1.1 SPMD (Semi-Permeable Membrane Device) passive sampling technique
Designed to mimic bioconcentration in animals. Long, flat plastic tube containing oil → “fatbags”.
Special plastic = mimics cell membranes. Oil inside = like purified fish fat → contaminants
dissolve as in fish tissues
How It Works? Place SPMDs in water (≈1 month). Hydrophobic contaminants di6use through
membrane. Contaminants accumulate in oil. Devices are collected & analyzed
Target Compounds: Neutral, hydrophobic organics with log Kow > 3
à Examples: PAHs (Polycyclic Aromatic Hydrocarbons), PCBs (Polychlorinated Biphenyls), Chlorinated pesticides, PBDEs
(Polybrominated Diphenyl Ethers) & Dioxins
Key Parameter: Octanol/Water Partition Coeeicient (Kow): Kow= concentration in octano phase/ concentration in aqueous phase
àIndicates hydrophobicity & tendency to bioaccumulate
2.2 Monitoring polar organic contaminants- adsorption
2.2.1 POCIS (Polar Organic Compound Integrative Sampler) passive samplers
Designed for water-soluble organic chemicals. Targets compounds with log Kow < 3
à Common analytes: -Pharmaceuticals & illicit drugs -Polar pesticides
Also e6ective for some compounds with log Kow > 3 (e.g., steroidal hormones, fragrances, triclosan,
wastewater-related compound
Calibration: Performance Reference Compounds (PRCs) embedded during fabrication. Measure PRC loss during deployment
→ corrects sampling rate for field conditions. Requires mathematical modeling for final concentration calculations
1 Chapter 1: Sample preparation
1.1 Examples
1.1.1 Re-use of treated wastewater for irrigation & groundwater
recharge
Environmental Impacts and Public Perception:
à Water scarcity challenge: Not enough water for irrigation.
à Domestic wastewater collected → sent to Wastewater Treatment Plant (WWTP) à e6luent reused
à Applications of treated wastewater: -Agricultural use: Irrigation of crops.
-Land application: Soil/plant growth.
-Groundwater recharge: Use for irrigation.
à Monitoring required: Continuous water quality monitoring. + Policy relevance
1.1.2 Hauts -de-France heaps (SH)
Study focus: Leaching impact of slag heaps. à Cultural value: UNESCO World Heritage site.
à Environmental aspect: Located Sensitive Natural Areas → fragile ecosystems.
1.1.3 Per- and Polyfluoralkyl Substances
3M scandal (Belgium, 2021): Large amounts of PFOS (perfluorooctanesulfonic acid) and PFOA (perfluorooctanoic acid) discovered
in 2018. Found near the 3M site (produced until 2002). Linked to excavation works for the Oosterweel link project.
What = PFAS? Synthetic industrial chemicals, Structure: Hydrophobic carbon chain (fluorine atoms) + hydrophilic functional group.
à Risks: Persistent in environment (“forever chemicals”). Harmful human & animal health.
1.2 Environmental analysis and monitoring: chain of actions
1) Policy Question: Defines what to monitor, why, and for whom.
2) Design & Planning: Select indicators/parameters (chemical,
physical, biological). Decide on sampling locations, frequency, duration.
Choose methods (in situ measurements. lab-based vs. In situ sampling).
3)Sampling: Collect representative samples from the environment.
Minimize contamination or alteration during collection.
4)Sample Handling & Storage: Label and document properly for traceability. Preserve
samples (temperature, chemical preservatives, darkness).
5)Transport: Deliver samples to the lab without changes to composition.
6)In Situ Measurement & Sampling: On-site measurements (pH, temperature, dissolved oxygen, noise, radiation).
Advantages: real-time data, fewer sample alterations.
7)Analysis: Lab methods using instrumental, chemical, biological methods, ensure accuracy, precision, detection limits, QC
8)Data Treatment & Interpretation: Raw data must be processed and cleaned (calibration, error checks, statistical treatment).
Results are compared to standards, thresholds, or baseline values. Final output answer original policy/management question.
1.3 Fundamentals of sample preparation for environmental analysis
Purpose: Direct injection rarely possible: Environmental samples require pretreatment before analysis. (Time-consuming)
à Main roles: -Homogenize sample / remove moisture → air/freeze drying, grinding, sieving.
-Adjust analyte concentration → pre-concentration (trace analysis) or dilution (high contamination).
-Remove interferences → extraction, purification.
-Change sample phase → adapt to instrument (e.g., liquid for HPLC, gas GC).
-Liberate analyte from matrix → e.g., digestion, solid-phase extraction.
-Modify chemical structure → derivatization for better detection (HPLC/GC).
When Preparation is Needed (and When Not): Not always required: e.g., drinking water, some freshwater samples (ICP-MS
sensitivity su6icient). Highly demanding: → very time-consuming.
Categories of Metal Analysis Preparation:
à Metals in dissolved phase: Filtration & Extraction / pre-concentration (for total analysis or speciation, chromatography)
à Metals particulate/solid phase: Digestion(total digestion or selective extractions)&Chromatographic extraction speciati
, Forms of Metals in Aqueous Samples:
-Dissolved metals: Hydrated ions, complexes, colloids. Operational definition: pass
through 0.45 µm filter (unacidified sample).
-Suspended metals: Bound to oxides (Fe–Mn, Ca), silicates, or organic matter. Defined as
metals retained on 0.45 µm filter (acidified sample).
-Total metals: Metals unfiltered sample after acid digestion =dissolved + suspended fraction
Filtration in field to avoid changes: à Small volumes → syringe + filter. à Large volumes → vacuum or pressure filtration.
à Pressure filtration: for anoxic samples, using inert gas to prevent oxidation.
1.4 On site filtration (for dissolved trace metals)
Prevents changes in dissolved/particulate phases after sampling.
à Methods: Disposable filters (0.45 µm or 0.2 µm) → field use, small volumes. Vacuum or pressure
filtration → larger volumes, lab-based. Acidify immediately after filtration.
à Partitioning: Partition coe6icient: Kd = Mp]/[Md]
[Mp] = particulate metal concentration & [Md] = dissolved metal concentration
logKd = a6inity of metals for particulate vs. dissolved phase.
Extraction & Pre-Concentration (aqueous samples):
Why? Low concentrations (e.g., Ra) & Matrix interferences (e.g., salts in seawater → ICP-MS issues).
Methods: -Liquid-liquid extraction (LLE): Complexation of metals (e.g., ADDC, DDDC, pH 4).
Extract complexes into organic solvent (e.g., freon), back-extract with acid.
-Solid-phase extraction (SPE): Complexation with dithiocarbamate: C18 cartridges (organic complexes).
Chelating resin columns (e.g., Chelex 100, MnO₂ for Ra).
Procedure SPE: 1) Cartridge Selection: Chose sorbent (reverse or normal phase, ion exchange,) depend sample & analyte.
2) Conditioning: Rinse sorbent with solvent to activate/prepare the surface.
3) Sample Loading: Ensure matrix compatibility , analytes bind to sorbent phase
4) Washing: Pass solvent (usually same as sample matrix) to remove unretained/unwanted components.
5) Elution: Minimal solvent to release analytes, leaves impurities behind. Collect the eluate à analysis
1.5 Solid Samples: Metal Speciation & Extractions
à Importance of Speciation: Metals in solids exist in dieerent forms (speciation).
Speciation matters for toxicity, bioavailability, and mobility.
à Approaches: -Total extractions → complete dissolution.
-Selective extractions → extract labile/available forms.
-Sequential extractions → successive steps to assess partitioning.
1) Total Extractions (Acid Digestion): Acid choice depends on matrix:
(a) Clean / easily oxidizable → HNO₃ (b) Di6icult organic matter → HNO₃–HClO₄
(c) Sediments → HNO₃–HCl–HF (complete digestion) or HCl–HNO₃ (aqua regia) = pseudo-total digestion
(f) Biological samples → HNO₃–H₂O₂
Why HNO₃ is widely used? -Dual role: Acid + oxidizing agent. Dissolves oxides (e.g., CaO + H₃O⁺à Ca2+ +3H2O). Oxidizes zero-
valence metals (e.g., Fe, Cu → ions).
-Does not form insoluble salts, unlike HCl or H₂SO₄.
Digestion Methods:
-Hotplate digestion → under fume hood. Required to liberate analyte from sample matrix.
-Microwave-assisted digestion → faster, better control.
2) Selective Extractions: Goal: extract specific fractions of metals for determining trace metal partitioning, mobility &
bioavailability. No method isolates only one phase → results are operationally defined.
à Common reagents & fractions: -Acetic acid → dissolved, weakly bound, carbonate fraction.
-EDTA → complexable fraction. -HCl (1M) → acid volatile sulfides (AVS) + associated trace metals.
-AVS > trace metals → non-toxic. -AVS < trace metals → bioavailable = toxic risk.
-HNO₃ or HNO₃/H₂O₂ → anthropogenic/acid extractable metals
, 3) Sequential Extractions: Successive extractions → reveal partitioning and stability. à BCR Protocol
: 1 → Exchangeable ions & Carbonate/Phosphate-Bound Metals (Ca²⁺, Fe²⁺) Reagent: acetic acid (0.11M).
2 → Reducible metals. Reagent: NH₂OH·HCl (0.1 M) in HNO₃ (pH 2).
3 → oxidizable metals (sulphidic & organic bound). Reagent:H₂O₂ (8.8 M), applied twice. Followed NH₄Ac/HOAc (pH 5).
4 → residual fraction. Reagent: HF/HNO₃. Target: Refractory carbon, sulfides, silicates → strongly bound, not bioavailable
Certified Reference Materials (CRM): Provide true values of analytes for some environmental matrices.
à Uses: -Verify analytical methods. -Quality control in total, partial, or sequential extractions.
à QC in selective extractions → spike additions.
1.6 Enrichment factor (EF)
Purpose: Compare "natural" vs. "polluted" concentration levels of elements/compounds.
Formula: EF = (X/Alsample)/(X/Alreference) X = element concentration, Al = reference element (stable, crustal origin)
Interpretation of EF values: EF < 2 → Deficiency to minimal enrichment 2 < EF < 5 → Moderate enrichment
5 < EF < 20 → Significant enrichment 20 < EF < 40 → Very high enrichment
EF > 40 → Extremely high enrichment
1.7 In situ sampling (in situ measurements)
Direct field measurements without transporting samples
Common Parameters & Instruments: -pH → pH electrode -Temperature → Thermometer
-Turbidity → Turbidity sensor/meter -Conductivity → Conductivity meter -Dissolved oxygen → O₂ electrode
-Specific ions (F⁻, S²⁻) → Ion-selective electrodes -Trace elements → Passive sampler technique
-Small-scale portable instruments →portable XRF, Hg analyser detection limits important
2 Chapter 2: In situ measurements by passive sampling techniques
Why Passive Sampling? àSpot sampling = instantaneous values → may miss short-term variations
à Increasing sampling frequency or using automatic samplers improves accuracy
àPassive samplers = time-integrated pollutant levels
à Principle: dieusion through barrier or permeation through membrane
à Limitation: consumable cost can be high
Types of Passive Sampling Techniques:
1. Non-polar organic contaminants (partition/absorption): SPMD, MESCO, SPME, Chemcatcher & DGT
2. Polar organic contaminants (adsorption):POCIS, Chemcatcher & DGT
3. Metals (chelating or other mechanisms): DGT
2.1 Non-polar organic contaminants (partition/absorption)
2.1.1 SPMD (Semi-Permeable Membrane Device) passive sampling technique
Designed to mimic bioconcentration in animals. Long, flat plastic tube containing oil → “fatbags”.
Special plastic = mimics cell membranes. Oil inside = like purified fish fat → contaminants
dissolve as in fish tissues
How It Works? Place SPMDs in water (≈1 month). Hydrophobic contaminants di6use through
membrane. Contaminants accumulate in oil. Devices are collected & analyzed
Target Compounds: Neutral, hydrophobic organics with log Kow > 3
à Examples: PAHs (Polycyclic Aromatic Hydrocarbons), PCBs (Polychlorinated Biphenyls), Chlorinated pesticides, PBDEs
(Polybrominated Diphenyl Ethers) & Dioxins
Key Parameter: Octanol/Water Partition Coeeicient (Kow): Kow= concentration in octano phase/ concentration in aqueous phase
àIndicates hydrophobicity & tendency to bioaccumulate
2.2 Monitoring polar organic contaminants- adsorption
2.2.1 POCIS (Polar Organic Compound Integrative Sampler) passive samplers
Designed for water-soluble organic chemicals. Targets compounds with log Kow < 3
à Common analytes: -Pharmaceuticals & illicit drugs -Polar pesticides
Also e6ective for some compounds with log Kow > 3 (e.g., steroidal hormones, fragrances, triclosan,
wastewater-related compound
Calibration: Performance Reference Compounds (PRCs) embedded during fabrication. Measure PRC loss during deployment
→ corrects sampling rate for field conditions. Requires mathematical modeling for final concentration calculations
