Test
for melamine in milk claimed as fastest yet
By Jane Byrne, 23-Jan-2009
Source of Article: http://www.foodproductiondaily.com/Quality-Safety/Test-for-melamine-in-milk-claimed-as-fastest-yet
A
detection method to determine levels of melamine in whole milk and milk
powder is highly sensitive and the fastest technique yet, claims researchers
based at Purdue
University.
Graham Cooks,
professor of chemistry at the university and leader of the team that the
developed the analysis method, said the technique is based on ambient
ionization using a low-temperature plasma (LTP) probe combined with tandem
mass spectrometry (MS/MS).
He said that it allows
detection
and quantitation of the industrial chemical in milk
powder, whole milk and other products at levels down to low parts per billion
(ppb) in analysis times in about 25 seconds: It is the fastest method so
far reported. It is also very specific and has sensitivity well below US Food
and Drug Administration (FDA) recommended levels.
Dairy scandal
Chinas dairy industry was
put at the heart of a global scandal in 2008, when thousands of children were
hospitalised and at least six died after traces of melamine
found its way into milk. Melamine is a chemical that can make it appear there
is more protein in a product, and has been linked to causing kidney stones
and other health problems.
While China
bore the brunt of the contamination fears, products around the world ranging
from infant formula to confectionery were recalled in fears over ingredient
sourcing in the country.
Research trigger
Cooks explained that
trigger for the development of the melamine test was the guidelines issued by
the FDA back in November limiting the chemical in dairy products to 1
part-per-million (ppm) or less:
"We took it as a
challenge to use simpler instrumentation and to develop a faster method that
allows the testing to be done on site and does not require pre-treatment of
samples, said Cook.
High throughput
He said that ambient
ionization methods, such as the low-temperature plasma ionization employed by
the Purdue group, can greatly reduce the time-intensive and sometimes
difficult requirements of mass spectrometers:
"The experiment
can be done in a high-throughput fashion, at a rate of two samples per
minute. This method provides the sensitivity, specificity and the
quantitative accuracy needed to meet the current urgent requirements for a
simple and reliable melamine determination in complex mixtures."
He explained that the
ionization source of the research project was developed over a period of a
few months but as a general method, not aimed at melamine, with the melamine
experiments completed in about ten days.
"Even without
direct contamination, trace amounts of melamine sometimes make their way into
consumable products because melamine is used in manufacturing and is found in
many packaging materials," Cooks said. "At trace levels, the chemical
is not known to be a health threat and has been deemed safe by the FDA. Our
analysis provides a way to determine whether the amounts present exceed safe
levels."
Availability
He told
FoodProductionDaily.com that a patent has been applied for in relation to the
detection method, while discussions in regards to its commercialization are
ongoing.
The research team, he
continued, have been involved in several other food safety related projects
in the past few months including studies focused on pesticide residues,
components in olive oil and natural sweeteners.
Their work in
developing a test for melamine in milk, which was funded by the US Office for
Naval Research, was published in the journal Chemical Communications.
|
