GB/T 5009.72-2003Method for analysis of hygienic standard of aluminum-wares for food use (English PDF)

6.2.2 Analysis procedures

6.2.2.1 Take 25.00mL of refined aluminum sample soaking solution and 5.0 mL of

lead standard working solution (equivalent to 5.0µg of lead); respectively place in two

25mL colorimetrical cylinders with stoppers; operate according to Article 6.2.2 of GB/T

5009.62-2003.

6.2.2.2 Take 2.00mL of recycled aluminum sample soaking solution and 10mL of

lead standard working solution (equivalent to 10.00µg of lead); operate according to

Article 6.2.2 of GB/T 5009.62-2003.

6.2.3 Result calculation

The same as Article 6.2.3 in GB/T 5009.62-2003.

Result expression. Refined aluminum report is less than or greater than 0.2 mg/L;

recycled aluminum report is less than or greater than 5mg/L.

7.1 Principle, Reagent and Instrument

The same as Method III in GB/T 5009.11-2003.

7.2 Analysis Procedures

Take 25.0mL of sample soaking solution; add the soaking solution into the

arsenic-measuring flask; add in 5mL of hydrochloric acid, 5mL of potassium iodide

solution, and 5 drops of acidic stannous chloride solution; shake up; stand for 10

minutes; add 2g of arsenic-free metallic zinc; immediately install the

arsenic-measuring tube that contains lead acetate cotton and mercuric bromide test

paper; place in the dark under 25°C ~ 30°C for 1 hour; take out the mercuric bromide

test paper; compare the test paper with the standard. The color spot shall not be

deeper than that of the standard.

Take 1.0mL of arsenic standard working solution (equivalent to 1.0 µg of arsenic); add

into the arsenic-measuring flask; add 5mL of acetic acid (4%) to 25mL; the following,

from "add in 5mL of hydrochloric acid", is operated at same time as the sample

soaking solution; this is standard arsenic spot.

7.3 Result Expression

Report is greater than or less than 0.04 mg/L.

8.6 Precision

The absolute difference between two independently-measured results under

repeatability condition shall not be greater than 10% of the arithmetic mean.

9.1 Atomic Absorption Spectrometry

In accordance with Section 7.1 in GB/T 5009.62-2003.

9.2 Dithizone Method

9.2.1 Principle, reagent and instrument

The same as Article 7.2.1~7.2.3 in GB/T 5009.62-2003.

9.2.2 Analysis procedures

Take 2 125mL-separating funnels; add 0.1mL of cadmium standard working solution

(equivalent to 1 µg of cadmium) and 50.0 mL of acetic acid (4%) into one separating

funnel; add 50.0 mL of sample soaking solution into the other separating funnel;

respectively add 2mL of potassium sodium tartrate solution, 10mL of sodium

hydroxide-potassium cyanide solution, and 2mL of hydroxylamine hydrochloride

solution into each separating funnel. The solution shall be shaken up after adding

each kind of reagent. The following is operated according to Article 7.2.4 of GB/T

5009.62-2003 - from "add in 15.0mL of dithizone-chloroform solution (0.1g/L)".

9.2.3 Result calculation

The same as Article 7.2.5 in GB/T 5009.62-2003.

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