Analysis method of hygienic standard for the hotte

Analysis method of hygienic standard for aluminum tableware containers

1 subject content and scope of application

this standard specifies the determination method of various hygienic indexes of various cooking utensils, tableware and containers formed by stamping or casting with aluminum as raw material in direct contact with food

this standard is applicable to the determination of various sanitary indicators of various cooking utensils, tableware and containers formed by stamping or casting with aluminum as raw material in direct contact with food

2 reference standard

gb/t5009.11 determination method of total arsenic in food

gb/t5009.14 determination method of zinc in food

gb/t5009.62 analysis method of hygienic standard for ceramic tableware containers

gb11333 hygienic standard for aluminum tableware containers

3 sampling method

take inspection samples according to 1 ‰ of the product quantity, and produce in small batches, with no less than 6 samples each time. The product name, batch number and sampling date shall be indicated respectively. Half of the samples are for assay, and the other half is kept for two months for arbitration analysis

4 appearance inspection and sensory indicators

the shape of the device is correct, the surface is smooth and uniform, without alkali stains, oil spots, and bubbles at the bottom. It shall comply with gb11333

5 soaking conditions

5.1 reagent

acetic acid (4%): measure 4ml glacial acetic acid or 11ml 36% acetic acid and dilute to 100ml

5.2 analysis steps

first wash the sample with soap, rinse it with tap water, then rinse it with distilled water, and dry it for standby

cooking utensils: take two pieces from each batch, add acetic acid (4%) to 0.5cm from the upper edge, boil for 30min, cover when heating, keep slightly boiling, and finally add acetic acid (4%) to the original volume. After 24h at room temperature, pour the above soaking solution into a clean glass bottle for testing

tableware: add boiling acetic acid (4%) to the place 0.5cm away from the upper edge -- senior department manager, add a glass cover, and place it at room temperature for 24h

the volume of soaking solution of flat containers that cannot contain liquid is calculated by multiplying 2ml per square centimeter of the surface area of the container. Divide the utensils into several simple geometric figures and calculate the total area

if the whole vessel is put into the soaking solution, it should be calculated on both sides, and the volume added into the soaking solution should be multiplied by 2

6 lead

6.1 atomic absorption spectrometry

operate according to Article 6.1 of gb/t5009.62

6.2 dithizone method

6.2.1 principle, reagent and instrument

are the same as 6.2.1 in gb/t5009.62

6.2.2 analysis steps

6.2.2.1 refined aluminum take 25.00ml sample soaking solution and 5.0ml lead standard solution (equivalent to 5.0 μ G lead), put them into two 25ml colorimetric tubes with plugs respectively, and operate according to Article 6.2.2 of gb/t5009.62 below

6.2.2.2 recover aluminum and take 2.00ml of sample soaking solution and 10ml of lead standard solution (equivalent to 10.0 μ G lead), the following shall be operated according to Article 6.2.2 of gb/t5009.62

6.2.3 calculation

is the same as article 6.2.3 in gb/t5009.62

expression of results: refined aluminum report is less than or greater than 0.2mg/l; The aluminum recovery report is less than or greater than 5mg/l

7 arsenic

7.1 principle, reagent and instrument

are the same as the second method in gb/t5009.11

7.2 analysis steps

take 25.0ml of sample soaking solution, transfer it into the arsenic measuring bottle, add 5ml of hydrochloric acid, 5ml of potassium iodide solution and 5 drops of acidic stannous chloride solution, shake it well and place it for 10min, add 2G of arsenic free metal zinc, immediately install the arsenic measuring tube with lead acetate cotton and mercury bromide test paper, place it in the dark at 25 ~ 30 ℃ for 1h, take out the mercury bromide test paper and compare it with the standard, and the color spot shall not be deeper than the standard

take another 1.0ml of arsenic standard solution (equivalent to 1.0 μ G arsenic), put it into the arsenic measuring bottle, add acetic acid (4%) to 25ml, and then operate the same operation as the sample soaking solution from "adding 5ml hydrochloric acid" below, and make standard arsenic spots

7.3 expression of results

report greater than or less than 0.04mg/l

8 zinc

8.1 principle

is the same as Chapter 6 of the second method in gb/t5009.14

8.2 reagent

8.2.1 acetic acid (4%)

the rest are the same as Chapter 17 in gb/t5009.14

8.3 instrument

visible spectrophotometer

8.4 analysis steps

suck 5.0ml of sample soaking solution, place it in 125ml separatory funnel, take another 6 separatory funnels, and add 0, 1.0, 2.0, 3.0, 4.0, 5.0ml of zinc standard solution (equivalent to 0, 1, 2, 3, 4, 5 μ G zinc). Add acetic acid (4%) to each separating funnel to 10ml

add 1 drop of methyl orange indicator solution respectively, and neutralize it with ammonia until the solution changes from red to yellow

add 5ml acetate buffer and 1ml thiostora ENSO to each separating funnel. The biological refining workshop of sunila paper mill in Finland began the experimental sodium sulfate solution for extracting lignin from papermaking black liquor. After mixing, add 10.0ml dithizone carbon tetrachloride solution (0.01g/l) respectively, shake for 2min, stand and layer, separate the carbon tetrachloride layer in a 1cm cuvette, adjust the zero point with a zero tube, and measure the absorbance at the wavelength of 520nm, Draw a standard curve for quantitative comparison

8.5 calculate

where: X1 - zinc content in sample soaking solution, mg/l

m - mass of zinc in the sample soaking solution taken during determination, μ g；

v - volume of sample soaking solution taken during determination, ml

expression of results: report the two significant digits of the arithmetic mean

8.6 allowable difference

relative difference ≤ 10%

9 cadmium

9.1 atomic absorption spectrometry

operate according to 7.1 in gb/t5009.62

9.2 dithizone method

9.2.1 principle, reagent and instrument

are the same as 7 in gb/t5009.62 Don't you think it's the same as buying a computer? Consider its hardware 2.1 ~ 7.2.3

9.2.2 analysis steps

take two 125ml separatory funnels, and add 0.1ml cadmium standard solution (equivalent to 1 μ G cadmium) and 50ml B @ scope of application: acid (4%), add 50.0ml of sample soaking solution to the other one, add 2 ml of potassium sodium tartrate solution, 10ml of sodium hydroxide potassium cyanide solution and 2ml of hydroxylamine hydrochloride solution to the separating funnel respectively, and shake well after each reagent is added. The following operation shall be carried out according to 7.2.4 in gb/t5009.62 from "adding 15.0ml dithizone chloroform solution (0.1g/l)"

9.2.3 calculation

is the same as 7.2.5 in gb/t5009.62

additional notes:

this standard is proposed by the health supervision department of the Ministry of health

this standard is drafted by the health and epidemic prevention station of Guangxi Zhuang Autonomous Region

this standard is interpreted by the food hygiene supervision and Inspection Institute of the Ministry of health, a technical centralized unit entrusted by the Ministry of health