How can I detect Nitrite in meat

In Europe many meat products like ham and smoked pork chop are cured. Curing is a process to preserve meat and sausages by addition of common salt. The meat develops a typical curing taste and becomes red in color. This process is important to avoid a grey coloration and a growth of microorganisms. However the reaction of nitrite with amino acids, can cause the formation of carcinogenic nitrosamines. Quantofix nitrite is ideal for this test.

Therefore it is important to minimize the concentration of nitrite in meat. A constant control of the concentration of nitrite in meat is necessary to avoid risks. The German directive “zweite Verordnung zur Änderung der Zusatzstoff-Zulassungsverordnung und anderer lebensmittelrechtlicher Verordnungen” (concerns approval of additives in food) defines limit values for the permitted concentration of nitrite in food. For meat products a maximum quantity of 150 mg/kg is prescribed. Sterilized meat products are not allowed to exceed the maximum quantity of 100 mg/kg. Similar uk legislation exists UK food additives guidelines

Test procedure
Sample preparation:
Take 5 g meat of the sample and place it into a mortar. Mince the meat (alternative use a homgeniser) and add 8 ml sodium acetate solution (13.6 g sodium acetate in 100 ml distilled water). Mix for 1 minute. Afterwards filter through a soft filter and press slightly to get some filtrate. Folded filter paper like camlab grade 111 is most suitable for the filtration.

Add 5 g meat into a mortar and mince.

Add 8 ml 1 N sodium acetate solution1) and mix for 1 minute.

Filter through a soft filter camlab grade 111.

Testing:
Dip the test strip into the filtrate for a few seconds. Remove the test strip and wait for 30 seconds. Compare the test field with the color scale on the tube. A red-violet coloration indicates the presence of nitrite ions.