Fundamentals of Environmental Sampling and Analysis

Chunlong (Carl) Zhang, PhD, is an Associate Professor of Environmental Science and Environmental Chemistry at the University of Houston-Clear Lake. He has over two decades of experience in academia, industry, and consulting. Dr. Zhang has firsthand, practical knowledge of environmental sampling and analysis from work in the field and in the lab. He is the author or coauthor of numerous articles and reports on contaminant fate/transport, environmental remediation, and environmental assessment.

Preface xvii

1. Introduction to Environmental Data Acquisition 1

1.1 Introduction 1

1.1.1 Importance of Scientifically Reliable and Legally Defensible Data 2

1.1.2 Sampling Error vs. Analytical Error During Data Acquisition 4

1.2 Environmental Sampling 5

1.2.1 Scope of Environmental Sampling 5

1.2.2 Where, When, What, How, and How Many 6

1.3 Environmental Analysis 6

1.3.1 Uniqueness of Modern Environmental Analysis 7

1.3.2 Classical and Modern Analytical and Monitoring Techniques 7

References 9

Questions and Problems 10

2. Basics of Environmental Sampling and Analysis 11

2.1 Essential Analytical and Organic Chemistry 11

2.1.1 Concentration Units 11

2.1.2 Common Organic Pollutants and Their Properties 14

2.1.3 Analytical Precision, Accuracy, and Recovery 16

2.1.4 Detection Limit and Quantitation Limit 17

2.1.5 Standard Calibration Curve 18

2.2 Essential Environmental Statistics 20

2.2.1 Measurements of Central Tendency and Dispersion 20

2.2.2 Understanding Probability Distributions 21

2.2.3 Type I and II Errors: False Positive and False Negative 25

2.2.4 Detection of Outliers 26

2.2.5 Analysis of Censored Data 28

2.2.6 Analysis of Spatial and Time Series Data 29

2.3 Essential Hydrology and Geology 30

2.3.1 Stream Water Flow and Measurement 30

2.3.2 Groundwater Flow in Aquifers 31

2.3.3 Groundwater Wells 32

2.4 Essential Knowledge of Environmental Regulations 35

2.4.1 Major Regulations Administrated by the U.S. EPA 35

2.4.2 Other Important Environmental Regulations 35

References 37

Questions and Problems 39

3. Environmental Sampling Design 45

3.1 Planning and Sampling Protocols 45

3.1.1 Data Quality Objectives 46

3.1.2 Basic Considerations of Sampling Plan 48

3.2 Sampling Environmental Population 49

3.2.1 Where (Space) and When (Time) to Sample 49

3.2.2 Obtain Representative Samples from Various Matrices 49

3.3 Environmental Sampling Approaches: Where and When 52

3.3.1 Judgmental Sampling 52

3.3.2 Simple Random Sampling 53

3.3.3 Stratified Random Sampling 54

3.3.4 Systematic Sampling 56

3.3.5 Other Sampling Designs 57

3.4 Estimating Sample Numbers: How Many Samples are Required 61

References 63

Questions and Problems 63

4. Environmental Sampling Techniques 69

4.1 General Guidelines of Environmental Sampling Techniques 69

4.1.1 Sequence of Sampling Matrices and Analytes 70

4.1.2 Sample Amount 70

4.1.3 Sample Preservation and Storage 71

4.1.4 Selection of Sample Containers 74

4.1.5 Selection of Sampling Equipment 76

4.2 Techniques for Sampling Various Media: Practical Approaches and Tips 83

4.2.1 Surface Water and Wastewater Sampling 84

4.2.2 Groundwater Sampling 86

4.2.3 Soil and Sediment Sampling 89

4.2.4 Hazardous Waste Sampling 90

4.2.5 Biological Sampling 92

4.2.6 Air and Stack Emission Sampling 92

References 93

Questions and Problems 94

5. Methodology and Quality Assurance/Quality Control of Environmental Analysis 97

5.1 Overview on Standard Methodologies 98

5.1.1 The U.S. EPA Methods for Air, Water, Wastewater, and Hazardous Waste 98

5.1.2 Other Applicable Methods: APHA/ASTM/OSHA/NIOSH/USGS/AOAC 103

5.2 Selection of Standard Methods 108

5.2.1 Methods for Sample Preparation 109

5.2.2 Methods for Physical, Biological, and General Chemical Parameters 111

5.2.3 Methods for Volatile Organic Compounds (VOCs) 112

5.2.4 Methods for Semivolatile Organic Compounds (SVOCs) 113

5.2.5 Methods for Other Pollutants and Compounds of Emerging Environmental Concerns 113

5.3 Field Quality Assurance/Quality Control (QA/QC) 115

5.3.1 Types of Field QA/QC Samples 116

5.3.2 Numbers of Field QA/QC Samples 118

5.4 Analytical Quality Assurance/Quality Control 118

5.4.1 Quality Control Procedures for Sample Preparation 118

5.4.2 Quality Control Procedures During Analysis 119

References 122

Questions and Problems 123

6. Common Operations and Wet Chemical Methods in Environmental Laboratories 127

6.1 Basic Operations in Environmental Laboratories 128

6.1.1 Labware Cleaning Protocols for Trace Analysis 128

6.1.2 Chemical Reagent Purity, Standard, and Reference Materials 129

6.1.3 Volumetric Glassware and Calibration 132

6.1.4 Laboratory Health, Safety, and Emergency First Aid 134

6.1.5 Waste Handling and Disposal 136

6.2 Wet Chemical Methods and Common Techniques in Environmental Analysis 137

6.2.1 Gravimetric and Volumetric Wet Chemical Methods 137

6.2.2 Common Laboratory Techniques 138

6.3 Analytical Principles for Common Wet Chemical Methods 141

6.3.1 Moisture in Solid and Biological Samples 141

6.3.2 Solids in Water, Wastewater, and Sludge (TS, TSS, TDS, VS) 141

6.3.3 Acidity, Alkalinity, and Hardness of Waters 142

6.3.4 Oxygen Demand in Water and Wastewater (DO, BOD and COD) 145

6.3.5 Oil and Grease in Water and Wastewater 148

6.3.6 Residual Chlorine and Chloride in Drinking Water 149

6.3.7 Ammonia in Wastewater 152

6.3.8 Cyanide in Water, Wastewater and Soil Extract 153

6.3.9 Sulfide in Water and Waste 154

References 155

Questions and Problems 155

7. Fundamentals of Sample Preparation for Environmental Analysis 159

7.1 Overview on Sample Preparation 160

7.1.1 Purpose of Sample Preparation 160

7.1.2 Types of Sample Preparation 161

7.2 Sample Preparation for Metal Analysis 162

7.2.1 Various Forms of Metals and Preparation Methods 162

7.2.2 Principles of Acid Digestion and Selection of Acid 163

7.2.3 Alkaline Digestion and Other Extraction Methods 165

7.3 Extraction for SVOC and Non-VOC from Liquid or Solid Samples 168

7.3.1 Separatory Funnel and Continuous Liquid–Liquid Extraction (LLE) 168

7.3.2 Solid Phase Extraction 171

7.3.3 Solid Phase Microextraction 173

7.3.4 Soxhlet and Automatic Soxhlet Extraction (Soxtec) 174

7.3.5 Ultrasonic Extraction 176

7.3.6 Pressured Fluid Extraction 177

7.3.7 Supercritical Fluid Extraction 177

7.3.8 Comparison and Selection of Organic Extraction Methods 178

7.4 Post-Extraction Clean-up of Organic Compounds 179

7.4.1 Theories and Operation Principles of Various Clean-up Methods 179

7.4.2 Recommended Clean-up Method for Selected Compounds 181

7.5 Derivatization of Non-VOC for Gas Phase Analysis 182

7.6 Sample Preparation for VOC, Air and Stack Gas Emission 183

7.6.1 Dynamic Headspace Extraction (Purge-and-Trap) 183

7.6.2 Static Headspace Extraction 184

7.6.3 Azeotropic and Vacuum Distillation 185

7.6.4 Volatile Organic Sampling Train 186

References 187

Questions and Problems 187

8. UV-Visible and Infrared Spectroscopic Methods in Environmental Analysis 190

8.1 Introduction to the Principles of Spectroscopy 191

8.1.1 Understanding the Interactions of Various Radiations with Matter 191

8.1.2 Origins of Absorption in Relation to Molecular Orbital Theories 193

8.1.3 Molecular Structure and UV-Visible/Infrared Spectra 200

8.1.4 Quantitative Analysis with Beer-Lambert’s Law 204

8.2 UV-Visible Spectroscopy 206

8.2.1 UV-Visible Instrumentation 206

8.2.2 UV-VIS as a Workhorse in Environmental Analysis 208

8.3 Infrared Spectroscopy 211

8.3.1 Fourier Transform Infrared Spectrometers (FTIR) 211

8.3.2 Dispersive Infrared Instruments (DIR) 213

8.3.3 Nondispersive Infrared Instruments (NDIR) 214

8.3.4 Applications in Industrial Hygiene and Air Pollution Monitoring 214

8.4 Practical Aspects of UV-Visible and Infrared Spectrometry 215

8.4.1 Common Tips for UV-Visible Spectroscopic Analysis 215

8.4.2 Sample Preparation for Infrared Spectroscopic Analysis 216

References 217

Questions and Problems 218

9. Atomic Spectroscopy for Metal Analysis 220

9.1 Introduction to the Principles of Atomic Spectroscopy 221

9.1.1 Flame and Flameless Atomic Absorption 221

9.1.2 Inductively Coupled Plasma Atomic Emission 225

9.1.3 Atomic X-ray Fluorescence 227

9.2 Instruments for Atomic Spectroscopy 227

9.2.1 Flame and Flameless Atomic Absorption 227

9.2.2 Cold Vapor and Hydride Generation Atomic Absorption 229

9.2.3 Inductively Coupled Plasma Atomic Emission 232

9.2.4 Atomic X-ray Fluorescence 233

9.3 Selection of the Proper Atomic Spectroscopic Techniques 235

9.3.1 Comparison of Detection Limits and Working Range 235

9.3.2 Comparison of Interferences and Other Considerations 236

9.4 Practical Tips to Sampling, Sample Preparation, and Metal Analysis 240

References 243

Questions and Problems 243

10. Chromatographic Methods for Environmental Analysis 246

10.1 Introduction to Chromatography 247

10.1.1 Types of Chromatography and Separation Columns 247

10.1.2 Common Stationary Phases: The Key to Separation 249

10.1.3 Other Parameters Important to Compound Separation 251

10.1.4 Terms and Theories of Chromatogram 254

10.1.5 Use of Chromatograms for Qualitative and Quantitative Analysis 258

10.2 Instruments of Chromatographic Methods 258

10.2.1 Gas Chromatography 258

10.2.2 High Performance Liquid Chromatography (HPLC) 260

10.2.3 Ion Chromatography 264

10.2.4 Supercritical Fluid Chromatography 265

10.3 Common Detectors for Chromatography 266

10.3.1 Detectors for Gas Chromatography 267

10.3.2 Detectors for High Performance Liquid Chromatography 272

10.3.3 Detectors for Ion Chromatography 274

10.4 Applications of Chromatographic Methods in Environmental Analysis 275

10.4.1 Gases, Volatile, and Semivolatile Organics with GC 276

10.4.2 Semivolatile and Nonvolatile Organics with HPLC 278

10.4.3 Ionic Species with IC 278

10.5 Practical Tips to Chromatographic Methods 279

10.5.1 What Can and Cannot be Done with GC and HPLC 279

10.5.2 Development for GC and HPLC Methods 280

10.5.3 Overview on Maintenance and Troubleshooting 281

References 284

Questions and Problems 285

11. Electrochemical Methods for Environmental Analysis 289

11.1 Introduction to Electrochemical Theories 290

11.1.1 Review of Redox Chemistry and Electrochemical Cells 290

11.1.2 General Principles of Electroanalytical Methods 292

11.1.3 Types of Electrodes and Notations for Electrochemical Cells 295

11.2 Potentiometric Applications in Environmental Analysis 296

11.2.1 Measurement of pH 296

11.2.2 Measurement of Ions by Ion Selective Electrodes (ISEs) 298

11.2.3 Potentiometric Titration (Indirect Potentiometry) 299

11.3 Voltammetric Applications in Environmental Analysis 300

11.3.1 Measurement of Dissolved Oxygen 300

11.3.2 Measurement of Anions by Amperometric Titration 302

11.3.3 Measurement of Metals by Anodic Stripping Voltammetry (ASV) 303

References 305

Questions and Problems 306

12. Other Instrumental Methods in Environmental Analysis 309

12.1 Hyphenated Mass Spectrometric Methods and Applications 310

12.1.1 Atomic Mass Spectrometry (ICP-MS) 310

12.1.2 Molecular Mass Spectrometry (GC-MS and LC-MS) 313

12.1.3 Mass Spectrometric Applications in Environmental Analysis 320

12.2 Nuclear Magnetic Resonance Spectroscopy (NMR) 322

12.2.1 NMR Spectrometers and the Origin of NMR Signals 322

12.2.2 Molecular Structures and NMR Spectra 325

12.2.3 Applications of NMR in Environmental Analysis 329

12.3 Miscellaneous Methods 329

12.3.1 Radiochemical Analysis 329

12.3.2 Surface and Interface Analysis 333

12.3.3 Screening Methods Using Immunoassay 334

References 335

Questions and Problems 336

Experiments 339

Experiment 1. Data Analysis and Statistical Treatment: A Case Study on Ozone Concentrations in Cities of Houston-Galveston Area 340

Experiment 2. Collection and Preservation of Surface Water and Sediment Samples and Field Measurement of Several Water Quality Parameters 344

Experiment 3. Gravimetric Analysis of Solids and Titrimetric Measurement of Alkalinity of Streams and Lakes 348

Experiment 4. Determination of Dissolved Oxygen (DO) by Titrimetric Winkler Method 352

Experiment 5. Determination of Chemical Oxygen Demand (COD) in Water and Wastewater 357

Experiment 6. Determination of Nitrate and Nitrite in Water by UV-Visible Spectrometry 362

Experiment 7. Determination of Anionic Surfactant (Detergent) by Liquid-Liquid Extraction Followed by Colorimetric Methods 366

Experiment 8. Determination of Hexavalent and Trivalent Chromium (Cr6+ and Cr3+) in Water by Visible Spectrometry 370

Experiment 9. Determination of Greenhouse Gases by Fourier Transform Infrared Spectrometer 374

Experiment 10. Determination of Metals in Soil–Acid Digestion and Inductively Coupled Plasma–Optical Emission Spectroscopy (ICP-OES) 378

Experiment 11. Determination of Explosives Compounds in a Contaminated Soil by High Performance Liquid Chromatography (HPLC) 382

Experiment 12. Measurement of Headspace Chloroethylene by Gas Chromatography with Flame Ionization Detector (GC-FID) 386

Experiment 13. Determination of Chloroethylene by Gas Chromatography with Electron Capture Detector (GC-ECD) 390

Experiment 14. Use of Ion Selective Electrode to Determine Trace Level of Fluoride in Drinking and Natural Water 392

Experiment 15. Identification of BTEX and Chlorobenzene Compounds by Gas Chromatography-Mass Spectrometry (GC–MS) 396

Appendices 402

A. Common Abbreviations and Acronyms 402

B. Structures and Properties of Important Organic Pollutants 407

C1. Standard Normal Cumulative Probabilities 417

C2. Percentiles of t-Distribution 418

C3. Critical Values for the F-Distribution 419

D. Required Containers, Preservation Techniques, and Holding Times 420

Index 423