Featured Research

from universities, journals, and other organizations

Pesticides Are In For It Now

Date:
December 12, 2008
Source:
ETH Zurich
Summary:
Chemists have developed a method to detect pesticide residues in foodstuffs -- a method that may also be of interest for other areas and may enable quality checks on a running basis.

Does away with the laborious extraction of pesticides from fruit and vegetable samples: the atmospheric pressure glow discharge source ionises the molecules on the surface of fruit peel. The molecules detached from the peel are then transferred into a mass spectrometer, where the chemical substances are analysed.
Credit: Zenobi Group

ETH Zurich chemists have developed a method to detect pesticide residues in foodstuffs – a method that may also be of interest for other areas and may enable quality checks on a running basis.

When customers stand in front of a fruit and vegetables shelf in a supermarket, they have their last chance to decide whether to buy standard Granny Smith apples or rather the Gala variety from an organic orchard?

If they decide in favour of Granny Smiths grown non-organically, they run the risk of ingesting harmful poisons together with valuable vitamins when they eat them. To combat pest organisms, fruit and vegetables are sprayed with plant protection agents, less euphemistically called pesticides. As a consequence, pesticide residues remain in the foods and are eaten by consumers in their diet. Renato Zenobi, Professor of Analytical Chemistry at the Laboratory of Organic Chemistry and his doctoral student Matthias Jecklin have now developed a mass spectrometric method enabling pesticide residues in foodstuffs to be detected quickly.

Mass spectrometer analyses toxic substances

A year ago the group presented a method based on mass spectrometry that enables the surfaces of objects of any kind to be analysed (cf. the ETH Life article of 7.9.2007). The new method to determine pesticides also uses what is known as a quadrupole time-of-flight mass spectrometer (QTOF-MS), but how do the chemical compounds get into the mass spectrometer?

Normally the pesticides in samples of fruit and vegetables need to be extracted before they can be analysed in a mass spectrometer. To avoid this time-consuming process, Jecklin built an atmospheric pressure glow-discharge source (APGD source), an electric source which generates a plasma, i.e. an ionised gas, at atmospheric pressure. When aimed at a piece of fruit peel, the plasma stream detaches molecules from the surface of the peel. These are then transferred directly into the mass spectrometer where the ions can be fragmented using a collision gas, thus enabling the researchers to identify the chemical substances in a fruit.

The method has many applications

Zenobi admits that, “Although this method can determine chemical compounds faster and more straightforwardly, the method is not yet a suitable way to quantify the amounts identified.” He says that, currently, the method can be used for preliminary probing – if pesticide residues are found in fruit and vegetables, conventional methods can be used to quantify how much of the substances has been discovered.

Nevertheless, the method for determining pesticide residues in fruit and vegetables is very promising. Zenobi and Jecklin have in mind quality checks on a running basis: various foodstuff samples that are analysed on a moving belt by the mass spectrometer. Zenobi says the method is also attractive for forensic and medical purposes. For example traces of drugs or explosives on surfaces could be detected, or human sweat and breath analysed – which could help to diagnose an illness quickly.


Story Source:

The above story is based on materials provided by ETH Zurich. The original article was written by Saskia Wegmann. Note: Materials may be edited for content and length.


Cite This Page:

ETH Zurich. "Pesticides Are In For It Now." ScienceDaily. ScienceDaily, 12 December 2008. <www.sciencedaily.com/releases/2008/11/081129173816.htm>.
ETH Zurich. (2008, December 12). Pesticides Are In For It Now. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2008/11/081129173816.htm
ETH Zurich. "Pesticides Are In For It Now." ScienceDaily. www.sciencedaily.com/releases/2008/11/081129173816.htm (accessed July 23, 2014).

Share This




More Plants & Animals News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Stone Fruit Listeria Scare Causes Sweeping Recall

Stone Fruit Listeria Scare Causes Sweeping Recall

Newsy (July 22, 2014) The Wawona Packing Company has issued a voluntary recall on the stone fruit it distributes due to a possible Listeria outbreak. Video provided by Newsy
Powered by NewsLook.com
Michigan Plant's Goal: Flower and Die

Michigan Plant's Goal: Flower and Die

AP (July 22, 2014) An 80-year-old agave plant, which is blooming for the first and only time at a University of Michigan conservatory, will die when it's done (July 22) Video provided by AP
Powered by NewsLook.com
Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Newsy (July 22, 2014) The 83 new genetic markers could open dozens of new avenues for schizophrenia treatment research. Video provided by Newsy
Powered by NewsLook.com
CDC Head Concerned About a Post-Antibiotic Era

CDC Head Concerned About a Post-Antibiotic Era

AP (July 22, 2014) Sounding alarms about the growing threat of antibiotic resistance, CDC Director Tom Frieden warned Tuesday if the global community does not confront the problem soon, the world will be living in a devastating post-antibiotic era. (July 22) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins