How to detect melamine in China food products

Melamine, a chemical normally used to make plastics and glues, is added to simulate acceptable protein levels. The chemical is at the centre of the latest tainted food scandal in China. Toxic ingredients from China killed or sickened thousands of dogs and cats in the US last year, prompting a public outcry. The WHO has said that as of Sept. 25, more than 54,000 infants and children in China had been taken to hospitals and clinics for treatment of urinary problems — such as renal tube blockages and kidney stones — related to the presence of melamine in infant formula and other dairy products. More than 14,000 infants had been hospitalized after ingesting the contaminated formula, of which a little less than 13,000 remained in hospitals. Some health experts said more must be done to ensure accuracy and overall food safety.

It is likely that the tainted milk was first diluted with water to increase its volume, and then had melamine added to boost nitrogen content, an indirect indicator of protein content. The chemical is not a substance used in any facet of food production.

People have to grind and homogenise the food samples, and then put them through a series of steps with an organic solvent to extract, clean and concentrate them before they analyse them for melamine.

GC-MS, LC-MS/MS & HPLC

The European Commission had recommended that all EU member states use gas chromatography-mass spectrometry (GC-MS) to analyze imports of wheat gluten and other raw materials from developing countries — in particular China. The US Food and Drug Administration (FDA) used the method to test for melamine and similar compounds in wheat gluten and pet food ingredients from China.

The samples are then separated into their parts using a process called Liquid Chromatography-tandem Mass Spectrometry (LC-MS/MS).

Mass spectrometry, which can detect very low evels of a compound, is then used to analyse them. LC-MS/MS testing is capable of detecting melamine levels as low as 0.05 parts per million (ppm). LC-MS/MS is a more precise instrument than GC-MS. This method would be used to test for melamine in the raw materials imported for use in creamers, milk powder and baby formula.

The technique is 500 times more sensitive in detecting melamine than high-performance liquid chromatography (HPLC), which was previously favored by the health department.

But the method to test for melamine in other, finished products remained unclear.

China Food Melamine-free Label

China Food Melamine-free Label

Taipei Report 2008-9-27

The Department of Health said five labs certified to test for melamine had been working night and day to cope with the growing backlog of samples.

Newly Department of Health Minister Yeh Chin-chuan checks products containing milk powder that are still on sale at a Taipei supermarket yesterday. The store has displayed copies of certification to prove that the products have been tested and found to meet Department of Health regulations.

RANDOM CHECKS

Meanwhile the DOH said yesterday that it would step up its random examination of food products from countries with dubious food safety standards.

“We have targeted products from certain countries with questionable standards and we do not rule out the possibility of carrying out the strictest batch-by-batch examinations of suspect products,” Yeh said, declining to name any countries.

Asked to comment on the scandal involving Pizza Hut, Yeh said it was only one case and that the source of the tainted ingredients had yet to be identified.

Pizza Hut on Friday reported to the DOH that 65,000 packets of cheese powder contaminated with up to 76.2ppm of melamine may have been consumed by its customers.

Pizza Hut has since recalled all unused cheese packets.

To date, five cases of kidney stones have been reported nationwide that could be linked to melamine.

CERTIFIED LABS

The Department of Health (DOH) said the nation’s five laboratories certified for testing, including the Food Industry Research and Development Institute, had been working night and day to cope with the growing backlog of companies that need to have products tested.

The DOH said it planned to have another 16 labs certified by the Taiwan Accreditation Foundation to help with melamine testing.

The labs, when ready, will accept samples seven days a week, it said.

Yeh said yesterday that the DOH would meet local health authorities in 25 counties and cities tomorrow to coordinate inspection procedures.

On Tuesday, the DOH will contact experts in the US, Japan, Australia, New Zealand and the EU to collaborate on standard inspection procedures and setting a threshold for melamine detection, he said.

'STRICTEST STANDARDS'

Yeh said the government was responsible for screening all imported foodstuffs and that all agencies, including the Bureau of Standards, Metrology and Inspection, the Bureau of Animal and Plant Health Inspection and Quarantine and the Bureau of Food and Drug Analysis would “apply the strictest screening standards.”

In response to a report in the Chinese-language Liberty Times (the Taipei Times’ sister newspaper) that customs personnel had not yet received lists of banned imports, Yeh said the task force had confirmed that instructions on banned products — including Chinese-made milk powder, other dairy products and vegetable-based proteins — had been issued as early as Tuesday.

Not one banned product has made it past Taiwan’s borders since, he said.

Most Chinese Goods up to Standard: Statistics

WASHINGTON -- "Made in China" labels mean good quality and value for money to US consumers as up-to-date statistics show most Chinese goods meet US standards.

The US Food and Drug Administration (FDA) said on June 28 a block on imports of five species of seafood from China because of so-called contamination.



The announcement, coupled with reports of contaminated pet food ingredients, led some American media to place an equals sign between "Made in China" and substandard products.

However, a closer look at the data on Chinese imports would reveal the majority of them meet US quality standards while only a fraction of them is problematic.

The FDA regulates food, drugs, medical devices and some radiation-emitting devices. FDA data showed Chinese seafood was seized at the border less than 400 times last year. By comparison, products from the Dominican Republic was stopped over 800 times and candy from Denmark was rejected more than 500 times during the same period.

The statistics also showed that in 2006 the sale of Dominican food in the United States amounted to 300 million US dollars and Danish food hit 400 million dollars, whereas the sale of Chinese food reached 3.8 billion dollars.

From July 2006 through June of this year, the agency's inspectors stopped 1,763 food shipments from India, followed by Mexico at 1,480, China 1,368, Dominican Republic 828, Denmark 543, Vietnam 533, Japan 508 and Italy 482 and Indonesia 460.

US government data indicated that China sent more food products, at least in terms of dollar value, into the United States than any of these countries except Mexico in 2006.

Mexico shipped 9.8 billion dollars worth of food to the United States, followed by China, which shipped 3.8 billion dollars. By comparison, Italy shipped 2.9 billion dollars worth of food to the United States, followed by Indonesia at 1.5 billion, India 1.2 billion, Vietnam 1.1 billion and Japan 500 million.

At the same time the FDA issued an import alert for Chinese fish, it also issued alerts for Mexican cantaloupes and basmati rice from India among others.

In terms of food violation counts, Mexico and India are well ahead of China. Salmonella mostly found on spices, seeds and shrimps is the frequent reason for the denial of entry from India. Filth is the major reason that food from Mexico, including candy, chilies, juice, seafood and cheese, was rejected.

A recent report issued by China's quality watchdog, the General Administration of Quality Supervision, Inspection and Quarantine, sheds more light on the issue.

Last year, less than 1 percent of the Chinese food products were rejected by the United States due to quality problems, the report said, adding that the figure is even lower than the percentage of substandard USfood products China rejected last year.

Carl Nielsen, a retired FDA official who oversaw import operation and policy, said no single country should be faulted for quality problems.

"What we are experiencing is massive globalization," he told The New York Times.

Globalization urges businesses all over the world to seek the utmost cost-saving products to achieve maximum profits. In so doing, importers do everything in their power to drive down prices of products whereas exporters go all out to reduce costs, Nielsen said.

Wherever there is a loophole in quality oversight, there is a hotbed of poor-quality or substandard products, he added.

Since any merchandise could be the result of international trade, problems with quality may rise anywhere during the process, from raw materials and manufacturing to distribution.

Improving food safety, therefore, needs the joint efforts of governments at all levels at home and cooperation among countries when it comes to conveying complete and correct quality information to the consumers.

Source: China Daily