Determining the Impact of Pharmaceutical and Illicit Drug Levels in NY/NJ Waterways with LC–MS/MS


Maria Concheiro of John Jay College (New York City) spoke to LCGC International about her research identifying and quantifying pharmaceuticals and drugs of abuse in river water samples collected from the Hudson and East Rivers in New York City, as well as investigating the possible source of these micropollutants

The presence of pharmaceuticals and drugs of abuse in surface and groundwater poses a threat to nontarget organisms using the water throughout their lifecycle chain. Maria Concheiro of the Department of Sciences at John Jay College of Criminal Justice (New York, NY) and her co-authors recently published a paper presenting their work identifying and quantifying a panel of 28 commonly prescribed pharmaceuticals and high‐prevalence drugs of abuse in river water samples collected from 19 locations in the Hudson and East Rivers in New York City, as well as investigating the possible source (wastewater treatment plants or combined sewer overflows) of these micropollutants. Concheiro spoke to LCGC International about her research.

How severe a problem are organic micropollutants (OMPs), specifically pharmaceutical and illicit drugs, in NY/NJ waters, and what are the specific challenges compared to other possible contaminants?

Pharmaceutical and illicit drugs are pharmacologically active substances that may produce their effects even at low doses. Therefore, their presence in the aquatic environment may impact the well-being of different types of organisms. Also, these substances are pseudo-persistent because they are continuously release into the water. Currently, there is insufficient environmental risk assessments for these substances, and limited information about their presence and concentrations in the environment. The goal of this study was to address this second issue and investigate what drugs and at what concentrations are present in the New York/New Jersey waterways, and what the source of these drugs is.

You state in your article that the majority of known OMPs are not on any existing drug monitoring lists. Why is this the case?

In my opinion, this is because more data about their environmental impact and presence are necessary to be able to include them in this type of lists and enforce their monitoring by environmental agencies.

The primary goal of your study was to identify and quantify a panel of 28 commonly prescribed pharmaceuticals (mood‐altering drugs, cardiovascular drugs, antacids, antibiotics) and high‐prevalence drugs of abuse (cocaine, amphetamines, opioids, cannabis) in river water samples collected from 19 locations in the Hudson and East rivers in New York. How did your study identify and quantify the presence of pharmaceuticals and drugs of abuse in river water samples, and what were the most frequently detected compounds?

To identify and quantify these 28 substances in river water, we developed an analytical method by liquid chromatography-tandem mass spectrometry (LC–MS/MS). Before the instrumental analysis by LC–MS/MS, we clean-up and concentrated the river samples using solid phase extraction cartridges. In the LC–MS/MS, we performed the chromatographic separation in reversed-phase and the data was acquired in multiple reaction monitoring mode (MRM), acquiring two MRM transitions per compound. The most intense transition was used for quantification and the second transition was used as qualifier. To guarantee the accuracy, precision, sensitivity and specificity of the method, this was validated following forensic toxicology standards.

In this study, we collected river samples from 19 different locations in the Hudson and East Rivers for 13-14 weeks during Summer 2021 and Summer 2022. The most prevalent drugs we found were two antihypertensive drugs (metoprolol and atenolol), stimulant drugs, such as cocaine, its metabolite benzoylecgonine, and methamphetamine, and the main metabolite of methadone (medication to treat opioid use disorder).

Were there any particularly interesting findings that stand out from a geographical or sociological perspective?

The drugs found in the river water did match the consumption habits of the population; both antihypertensives are highly prescribed in the area, and in New York City there is a high prevalence of cocaine and methamphetamine use. But we must keep in mind that other substances frequently consumed in the city, such as cannabis, were not detected in this type of sample. The chemical explanation to this observation could be due to the high lipophilicity and adsorption of cannabinoids to particulates in the sewage system and the aquatic environment, which probably make them undetectable in river water.

Are there any substances that are easier or harder to detect in an average sample?
Many of the drugs we included in our panel are basic drugs with similar physico-chemical properties, which facilitated the procedure to analyze them simultaneously. But in our method, we also included the cannabinoid 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THC-COOH). THC-COOH is a neutral/acidic compound that behaves differently from the other drugs. This was a challenge during the method development, but we were able to find a common extraction procedure from one 50 mL-water aliquot with 2 different elutions, and the eluents were injected employing two different chromatographic separations, one for THC-COOH and another one for the other 27 drugs.

Are you aware of other researchers and their work to identify pharmaceuticals and drugs of abuse in various water sources?

Yes, of course, there are previous publications for the detection of pharmaceuticals and drugs in river water in different parts of the world, and in other types of water, such as wastewater. Regarding river water, most of the publications have focused more in pharmaceuticals than in drugs of abuse. Specifically in New York, there are publications by Pochodylo and Helbling (2) and by Cantwell and co-authors (3) that investigated the presence and the source of pharmaceuticals in different locations throughout the Hudson River. Our findings agreed with these previous investigations, being atenolol and metoprolol among the most detected analytes. Neither of these publications, however, focused on drugs of abuse, and sample collection was performed for a short period and in a few locations in the city.

Are there any other findings you’d like to share?

In our study, we also focused on understanding what the source of pharmaceutical and illicit drugs was. We evaluated the impact of combine sewage overflow (CSO) and wastewater treatment plants (WWTPs). We observed more drugs and higher concentrations were detected in water contaminated by Enterococci and after rainfall, indicating CSO impact. However, the presence of drugs in clean water and during periods of dry weather indicates that WWTPs may also contribute to the presence of drugs in the rivers.

Were there any limitations or challenges you encountered in your work?

This project was labor intensive, but it run smoothly. The sample collection is always a challenge but, in this case, we were able to collect more than 400 samples throughout two years in 19 different locations thanks to the collaboration with the local environmental organization, the New York City Water Trail Association, specifically the Citizens’ Water Quality Testing volunteers.

As a limitation we may say that, for this study, we collected samples at a single instance, showing a snapshot of the bacterial and drug concentration in specific locations close to CSOs. We could not collect 24 h composite samples from different locations in the river, which may offer a more comprehensive representation of the average content in the river.

What best practices that can you recommend in this type of analysis for both instrument parameters and data analysis?

The best practices that we can recommend regarding the LC–MS/MS analysis of this type of samples is to include two MRM transitions to determine the presence of the different drugs. This approach increases the specificity of the assay. Also, in the same batch as the authentic samples to be analyzed, we must include calibrators and quality control samples to guarantee the accurate and precise quantification of the target compounds.

It is important as well to perform a full validation of the analytical method before its application to the analysis of authentic samples. The validation procedure will determine how specific, sensitive, accurate, and precise is our method to be able to provide reliable data.

Do you imagine these techniques to be adaptable to other industries, or perhaps other materials in the water?

Definitely. As we get more information about what chemicals are present in our environment and what is the impact that they may have in different types of organisms, the surveillance of these substances will become regulated. Our methodology proved to be specific, sensitive and robust, and could be used by any analytical laboratory.

What are the next steps in this research?

The next step in our research is to assess the environmental risk of the most prevalent pharmaceuticals and illicit drugs we found in New York City rivers. We’ll work with collaborators, Dr. Shu-Yuang Cheng from John Jay College and Dr. Joyce Lau from Farmingdale State College (East Farmingdale, NY) , to investigate what effects these drugs have on different types of organisms in the aquatic environment, such as oysters.

Marta Concheiro is Associate Professor of Toxicology at John Jay College of Criminal Justice, CUNY. Dr. Concheiro has more than 95 publications in peer-reviewed journals, and she has participated presenting her work at more than 50 professional toxicology meetings.  Photo courtesy of Dr. Concheiro.

Marta Concheiro is Associate Professor of Toxicology at John Jay College of Criminal Justice, CUNY. Dr. Concheiro has more than 95 publications in peer-reviewed journals, and she has participated presenting her work at more than 50 professional toxicology meetings. Photo courtesy of Dr. Concheiro.


1. Acosta, T.; Chavez, V.; Fernandez, N.; Perry. E.; Good, K.; Concheiro, M. The Impact of Combined Sewer Overflows on Pharmaceutical and Illicit Drug Levels in New York/New Jersey Waterways. Environ. Toxicol. Chem. 2024. DOI: 10.1002/etc.5891

2. Pochodylo, A. L.; Helbling, D. E. Emerging Investigators Series: Prioritization of Suspect Hits in a Sensitive Suspect Screening Workflow for Comprehensive Micropollutant Characterization in Environmental Samples. Environ. Sci.: Water Res. Technol. 2017, 3, 54–65. DOI:10.1039/C6EW00248J

3. Cantwell, M. G.; Katz, D. R.; Sullivan, J. C.; Shapley, D.; Lipscomb, J.; Epstein, J.; Juhl, A. R.; Knudson, C.; O'Mullan, G. D. Spatial Patterns of Pharmaceuticals and Wastewater Tracers in the Hudson River Estuary. Water Research 2018, 137, 335–343. DOI: 10.1016/j.watres.2017.12.044.

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