New Contaminants and the Scientific Tools Tracking Them
Explore the ScienceImagine an invisible world of chemical substances flowing from our homes, industries, and farms into our waterways and soil—substances that conventional water treatment plants weren't designed to remove.
These "emerging contaminants" include everything from pharmaceutical residues and personal care products to industrial chemicals and microplastics, present at concentrations so minute that they've largely escaped detection until recently. Thanks to revolutionary advances in analytical chemistry, scientists can now identify these contaminants at incredibly low levels, sometimes as minuscule as one part per trillion—equivalent to detecting a single drop of water in 20 Olympic-sized swimming pools.
Emerging contaminants (ECs) represent a remarkably diverse group of synthetic and naturally occurring chemicals that are increasingly being detected in environmental samples, not because they're necessarily new, but because our ability to find them has dramatically improved 4 . These substances have attracted growing scientific attention due to their potential ecological and human health impacts, coupled with analytical advances that now allow detection at trace levels 4 .
Pharmaceuticals & Personal Care Products
Endocrine-Disrupting Chemicals
Per- and Polyfluoroalkyl Substances
| Category | Examples | Primary Sources |
|---|---|---|
| Pharmaceuticals & Personal Care Products (PPCPs) | Ibuprofen, antibiotics, antidepressants, cosmetics | Human and veterinary medicine, personal care routines |
| Endocrine-Disrupting Chemicals (EDCs) | Natural & synthetic hormones, bisphenol A (BPA) | Industrial discharges, plastic manufacturing, pharmaceuticals |
| Per- and Polyfluoroalkyl Substances (PFAS) | PFOA, PFOS | Non-stick coatings, waterproof apparel, firefighting foam |
| Micro- and Nano-plastics (MNPs) | Plastic fragments (<5mm), synthetic fibers | Plastic waste degradation, personal care products |
| Novel Psychoactive Substances (NPS) | Synthetic cathinones, synthetic cannabinoids | Illicit drug manufacturing and consumption |
These contaminants have been implicated in various environmental and health concerns, from endocrine disruption in aquatic organisms to the development of antibiotic resistance and potential neurological effects in humans 4 6 . Perhaps most concerning is that these contaminants often escape conventional wastewater treatment processes, allowing them to enter rivers, lakes, and even drinking water supplies 4 .
As the diversity of emerging contaminants has expanded, so too has the need for more sophisticated ways to evaluate the analytical methods used to detect them. The scientific community has responded by developing comprehensive assessment frameworks that look beyond traditional metrics of analytical performance.
Analytical Performance
Environmental Impact
Practicality
This triadic approach forms the foundation of White Analytical Chemistry (WAC), which aims to balance environmental sustainability with practical functionality 1 . However, as analytical science continues to evolve, this framework is being expanded with new assessment tools:
This survey-based visual tool evaluates the innovative strength of analytical methods across 10 criteria, including sample preparation, instrumentation, data processing, regulatory compliance, and interdisciplinary applications.
This canvas-based visualization template condenses complex method descriptions into 12 keyword-based blocks—enhancing both reproducibility and communication.
These evolving evaluation frameworks reflect how modern analytical chemistry balances multiple competing priorities: the need for precision and sensitivity, but also environmental responsibility, practical utility, and innovative approaches 1 .
To understand how scientists are developing methods to detect emerging contaminants, let's examine a specific experiment focused on identifying novel psychoactive substances (NPS) in human saliva. A 2025 study published in Analytical Methods addressed the challenge of detecting synthetic cathinones ("bath salts") using capillary electrophoresis 3 .
Human saliva samples were collected directly from donors using non-invasive methods, making the technique potentially useful for real-world applications like roadside drug testing 3 .
A simple and fast pretreatment protocol was developed to prepare saliva samples for injection into capillary electrophoretic systems. This step is crucial for removing interfering substances that could affect results 3 .
Two complementary analytical approaches were employed:
The method was specifically designed to detect butylone and clephedrone (part of the synthetic cathinone family) and 2-aminoindane, all listed as psychoactive substances 3 .
The researchers successfully detected all target compounds with limits of detection ranging between 6-15 μM (micromolar) 3 . The methods were characterized in terms of detectability, reproducibility, and sensitivity. Based on these results, the team simulated a forensic application using CE-UV for 2-aminoindane and butylone at concentrations of 10 μM and 20 μM respectively, demonstrating the method's potential for real-world implementation 3 .
| Analyte | Class | Limit of Detection (μM) | Reproducibility | Optimal Detection Method |
|---|---|---|---|---|
| Butylone | Synthetic cathinone | 6-15 μM | Successful | CE-UV / CE-MS |
| Clephedrone | Synthetic cathinone | 6-15 μM | Successful | CE-UV / CE-MS |
| 2-aminoindane | Psychoactive substance | 6-15 μM | Successful | CE-UV / CE-MS |
This experiment highlights several advantages of the capillary electrophoresis approach for detecting emerging contaminants: it requires low sample volumes, offers high separation efficiency, and provides complementary detection options that can be selected based on available resources and specific application needs 3 . The success of this method is particularly significant given the historical difficulty in analyzing novel psychoactive substances, which often have short emergence lifetimes and varying potencies 5 .
Modern analytical chemistry relies on a diverse array of reagents, materials, and technologies to detect emerging contaminants at increasingly lower concentrations.
| Tool/Reagent | Function | Application Examples |
|---|---|---|
| Liquid Chromatography-Mass Spectrometry (LC-MS/MS) | Separates and identifies compounds based on mass | PFAS, pharmaceuticals, endocrine disruptors 4 7 |
| Capillary Electrophoresis Systems | Separates ions based on charge and size | Synthetic cathinones in saliva, pharmaceutical compounds 3 |
| Molecularly Imprinted Polymers | Artificial antibodies for specific molecular recognition | Selective extraction of target analytes from complex samples |
| Supercritical Fluid Chromatography | Uses CO2 as mobile phase for better separation | Short-chain PFAS, pharmaceuticals, antibiotics 7 |
| Immunoassay Kits | Antibody-based detection for specific compounds | Screening for benzodiazepines and other NPS classes 5 |
| Solid-Phase Extraction Cartridges | Concentrates and purifies analytes from liquid samples | Preparing water samples for PPCP analysis 2 |
| Derivatization Reagents | Chemically modifies compounds for better detection | Enhancing sensitivity for hormones and steroids in GC-MS |
Each of these tools offers distinct advantages for particular applications. For instance, while high-resolution mass spectrometry provides unparalleled identification capabilities for unknown compounds, traditional immunoassays remain valuable for specific compound classes like benzodiazepines due to their cost-effectiveness and rapid results 5 . The selection of appropriate analytical tools depends on multiple factors, including the target analytes, required sensitivity, sample matrix, and available resources 8 .
The field of analytical chemistry continues to evolve rapidly, with several promising technologies poised to enhance our ability to monitor emerging contaminants:
Researchers are developing methods using supercritical carbon dioxide as an alternative to traditional liquid chromatography. This approach offers advantages for detecting short-chain and ultrashort-chain PFAS, which conventional methods often miss.
Instead of just looking for specific known compounds, scientists are increasingly using high-resolution mass spectrometry to conduct "non-targeted analysis," which can identify unexpected or previously unknown contaminants.
The field is moving toward miniaturized devices and automated systems that can provide real-time monitoring capabilities in the field rather than requiring samples to be transported to laboratory facilities.
As methods become sensitive enough to detect contaminants at parts-per-trillion levels, scientists must contend with potential background contamination from common consumer products present in laboratory environments.
Despite these advances, significant challenges remain. As methods become sensitive enough to detect contaminants at parts-per-trillion levels, scientists must contend with potential background contamination from common consumer products present in laboratory environments 8 . This is particularly problematic for ubiquitous compounds like PFAS, which can be found in many legacy laboratory equipment and materials 8 .
Additionally, the rapid evolution of analytical methods presents challenges for long-term monitoring projects, as method changes can compromise data comparability over time 8 . Regulatory standards often struggle to keep pace with both the emergence of new contaminants and the development of methods to detect them 2 8 .
The journey to understand and address emerging contaminants represents one of the most significant challenges in modern environmental science.
As we've seen, this invisible chemical world—spanning from pharmaceuticals and personal care products to microplastics and novel psychoactive substances—requires equally sophisticated analytical methods to detect and quantify. The field has evolved from simply asking "Is this method precise?" to more comprehensive questions: "Is it sustainable? Is it practical? Is it innovative?"
Thanks to advances in analytical chemistry, we're increasingly able to shed light on this invisible world, understanding not just what contaminants are present, but what risks they might pose to ecosystems and human health. While challenges remain—in detection capabilities, method standardization, and regulatory frameworks—the scientific tools at our disposal continue to improve in sensitivity, efficiency, and accessibility.
As Diana Aga, director of the University at Buffalo's RENEW Institute, and her graduate student Karla RÃos-Bonilla exemplify through their work on PFAS detection, scientific innovation continues to push the boundaries of what we can detect and understand 7 . Their research, along with countless other studies worldwide, ensures that we're not powerless against the rising tide of emerging contaminants but are instead developing the knowledge and tools needed to address this invisible invasion.