METTLE FOR METAL
Toxic or not? Dr. Martijn van der Lee of RIKILT in the Netherlands explains
how speciation of heavy metals helps answer the question.
Heavy metals are complex. While many
are released into the environment as a
result of natural emissions such as volca-
noes and forest fires, others are released
by human activities like mining, industrial
processes and the burning of fossil fuels
and garbage. Some heavy metals are toxic
in their elemental or mineral state. Heavy
metal-containing compounds, when
added to a solution, often create a variety
of heavy metal ions, each with
their own chemistries
and toxicities.
acronym RIKILT, is an independent research institute associated with the University of Wageningen and it gets most
of its funding through grant-writing and
government contracts. As such, Dr. van
der Lee’s laboratory provides analytical
services to government agencies responsible for monitoring the safety of food
and feed throughout Holland.
in food and feed—mercury and arsenic—
are of particular interest since metal
speciation is performed at the RIKILT
laboratory, he explains.
HgIn addition, these
heavy-metal ions combine
with a bewildering array of organic
compounds that make up the machinery
of life, often with adverse consequences
for the plant, animal, or environment in-
volved. As a result, it takes a special kind
laboratory and a special kind of person to
work with heavy metals. Dr. Martijn van
der Lee is just that type of person.
More importantly, Dr. van der Lee’s
team at RIKILT is the National
Reference Laboratory for analyz-
ing heavy metals in food and feed
in Holland, meaning they share
knowledge related to heavy metals
in food and feed by offering training
and courses on analytical methods
and European food legislation with
other Dutch (field) laboratories.
As a result, says Dr. van der Lee,
“We have a duty to visit other
laboratories in the Netherlands to
see how they analyze official monitoring
samples, and to see if they do a good job.”
Mercury is a problem in many species
of fish consumed by humans because it
bioaccumulates in the marine environ-
ment. The problem starts when algae,
plankton, and other microorganisms in-
gest inorganic mercury and turn it into
methyl mercury, which is very soluble
in fats. When small fish ingest large
amounts of microorganisms, the methyl
mercury accumulates, and so on up the
food chain. Eventually, larger preda-
tory fish end up on our plates, where
the methyl mercury makes its way to
the human liver, kidney, and brain and
causes problems, particularly in young,
developing brains.
Dutch Food Safety Monitor
Dr. van der Lee relishes a challenge and
loves unraveling complex problems,
which is why he studies heavy metals in
food and feed. For the past six years, Dr.
van der Lee has worked at the Institute
of Food Safety in the Netherlands. The
Institute, generally known by its Dutch
A Closer Look
When asked about the types of samples
that are analyzed at RIKILT, Dr. van der
Lee explains that about 75% are animal
feed and the rest are food
samples provided
by the Dutch
Food
Inspection
Service.
Two of
the heavy
metals
analyzed
Arsenic can be highly toxic as well,
depending on its chemical structure.
Farmers often supplement animal diets
with mineral supplements to promote
growth and optimize organ functions.
These supplements may contain traces
of heavy metals, including inorganic
Dr. Martijn van der Lee is a scientist at RIKILT, the Dutch
Institute of Food Safety at Wageningen University and
Research centre in the Netherlands.
Thermo Scientific HPLC-ICP-MS
