Multi element detection in food

Heavy metal pollution has become an important source of pollution that affects human health today, so how to detect heavy metal pollution has become a very important issue. Below, based on national standards and my own experience, the editor has compiled methods for detecting multiple elements in food. Let's take a look with the editor.

1 Principle

After the sample is digested, it is determined by an inductively coupled plasma mass spectrometer. Qualitative analysis is carried out using a specific mass number of elements (mass to charge ratio, m/z), and quantitative analysis is performed using an external standard method. The intensity ratio of the mass spectrometry signal of the target element to the mass spectrometry signal of the internal standard element is directly proportional to the concentration of the target element.

2 Scope of application

This method is suitable for the determination of boron, sodium, magnesium, aluminum, potassium, calcium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, arsenic, selenium, strontium, key, tin, antimony, barium, mercury, lead, and cadmium in food.

3 standard products

3.1 Element storage solution (10 mg/L): Lead, cadmium, arsenic, selenium, chromium, tin, copper, manganese, nickel, barium, strontium, molybdenum, titanium, vanadium, cobalt, etc., using single element or multi-element standard storage solutions certified by the country and awarded standard substance certificates.

3.2 Element storage solution (10 mg/L): Lead, cadmium, arsenic, selenium, chromium, tin, copper, manganese, nickel, barium, strontium, molybdenum, titanium, vanadium, cobalt, etc., using single element or multi-element standard storage solutions certified by the country and awarded standard substance certificates.

3.3 Trace element storage solution (1000 mg/L): Sodium, potassium, calcium, iron, magnesium, aluminum, zinc, and other single element standard storage solutions certified by the country and awarded standard substance certificates are used.

3.4 Internal standard element storage solution (100 mg/L): Scandium, germanium, indium, rhodium, rhenium, bismuth and other single element or multi-element standard storage solutions certified by the country and awarded standard substance certificates are used.

Preparation of 4 standard solutions

4.1 Mixed standard working solution: Take 0.25mL of 3.1 multi-element standard stock solution and add it to a 25mL volumetric flask. Make up to the mark with nitric acid solution (5+95) for later use, with a concentration of 100mg/mL. Then, gradually dilute with nitric acid solution (5+95) to prepare a series of mixed standard working solutions, with concentrations of 0.1, 0.5, 1.0, 2.0, 5.0, and 10.0mg/mL, respectively. Note: Adjust the mass concentration range of each element in the standard series appropriately based on the concentration level of elements in the sample digestion solution.

4.2 Mercury standard working solution: Take 0.25mL of the 3.2 multi-element standard storage solution and add it to a 25mL volumetric flask. Make up to the mark with nitric acid solution (5+95) for later use, with a concentration of 100mg/mL. Then, gradually dilute with nitric acid solution (5+95) to prepare a mixed standard working solution series, with concentrations of 0.1, 0.5, 1.0, 2.0, 5.0, and 10.0mg/mL, respectively. Note: Adjust the standard series appropriately based on the mass concentration level of elements in the sample digestion solution