Emerging Contaminants in Water: Type and Testing

Water, water, everywhere, and every drop
and water analysis is the first line of defense
tested via a mass spectrometer. Such is the
for both people and the planet against the
dream of many a water analyst. Why such
unwelcome
consequences
of
pesticides,
zeal? Because the number of potential
plastics and other pollutants. Read on to find
water contaminants is growing by the year,
out how such contaminants are analyzed.
Water Types
Firstly, it’s worth distinguishing common water sources. There’s…
Drinking water
Groundwater
The safety of which is perhaps
The water sitting underground
the most paramount.
in saturated zones beneath the
land surface.
Wastewater
Seawater
The effluvium soup of industrial and
While unlikely to be drank by
agricultural activity. Many states and
people, seawater should be kept
nations require such outflow to be
contaminant-free for the sake of
tested and treated by the industrial
ocean life, natural beauty spots and
actors themselves prior to discharge
the health of seafood consumers.
in rivers and the sea. But secondary
testing is still crucial to ensure
regulatory compliance and safety.
Contaminants of
EMERGING CONCERN
Some contaminants are as old as the soil they leach from. Others are more recent concerns.
The USA’s Environmental Protection Agency (EPA) defines contaminants of emerging concern
(CECs) as chemicals that have not previously been detected in water or that are being detected
at significantly different levels than expected. Such CECs include…
Pharmaceuticals
Active pharmaceutical ingredients (APIs) can fil
ter
into streams, seas and groundwater via human
waste and municipal wastewater treatment out
flows.
In a 2022 global study, researchers found
the most commonly detected pharmaceuticals in
rivers included paracetamol, metformin, fexofen
adine,
sulfamethoxazole and metronidazole (both
antimicrobials) and gabapentin.
Personal care products
The EPA considers personal care products CECs
because little is known about their impact on the
environment. Examples of such chemicals include
hair and skin care products, baby care products, UV
blocking creams and facial cleansers.
Plasticizers
These artificial compounds, such as phthalates and
adipates, are added to products to increase plasticity.
They’re recognized as endocrine-disrupting chemicals,
which affect the body’s hormone systems, increasing
the risks of cancer, diabetes and reproductive disorders.
PFAS
Per-and polyfluoroalkyl substances (PFAS) are a group
of synthetic chemicals used to waterproof consumer
products like pans and packaging. They’re known as
“forever chemicals” because, thanks to their almost
unbreakable
highly-fluorinated alkyl chain backbone,
they don’t degrade naturally in the environment.
This hardiness is particularly concerning considering
the recent wave of research linking the chemicals to
cancers, high cholesterol and low birth weights.
Pesticides
Pesticides are nothing new; along with heavy
metals, they’re an enduring agricultural pollutant.
But a new type of pesticide, nano-pesticides, could
be an emerging contaminant of concern. These
nano-pest-killers rely on small particle sizes and
high surface areas, the consequences of which on
the environment are under-researched.
Plastics (micro)
A well-publicized CEC at this point, microplastics
can be accrued in the environment from such
innocuous items as synthetic clothing and rubber
tires. If caught in the solid sludge formed around
wastewater filtration, the plastics can be incidentally
captured and repurposed into fertilizer, thereby
entering the agricultural food system.
The dangers
CECS POSE
CECs have been linked to several harmful effects
on human health, including endocrine disrup
tion,
growth and development toxicity, neurotox
icity,
immunotoxicity, carcinogenicity and terato
genicity.
Microplastics can also serve as carriers
of antibiotic-resistant bacteria, viruses and other
pathogens, posing a risk of disease to humans
and other animals.
How to test
FOR CECS
CECs are as varied as the methods that test them,
but certain techniques have become favored.
When it comes to pharmaceuticals and per
sonal
care products, analysts are faced with
the task of finding the contaminants in parts
per million (µg/mL) or even parts per trillion
(pg/mL) concentrations in water samples. To
provide effective chromatographic separa
tion
at these minute levels, ultra-high perfor
mance
liquid chromatography-tandem mass
spectrometry (UHPLC-MS/MS) has risen as a
viable method, as UHPLC provides optimal
chromatographic separation while MS/MS
provides optimal specificity
Plasticizers and other endocrine-disrupting
compounds are often tested via liquid chro
matography-
tandem mass spectrometry (LC/
MS/MS). The same technique is also regularly
used when testing water samples for pesti
cides
and PFAS.
Fourier transform infrared (FTIR) spectrosco
py
and FTIR microscopy have become stan
dard
methods for the detection and identifi
cation
of microplastics in all four water types
and sample matrices. IR imaging, in particu
lar,
is an excellent analytical technique for the
detection and identification of microplastics
present in an unknown sample.
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