GB/T 33324-2016Determination of heavy metal content of latex products—Inductively coupled plasma atomic emission spectrometry (English PDF)

Foreword

This Standard is drafted in accordance with the rules given in GB/T 1.1-2009.

1 Scope

This Standard specifies the method to determine the content of 10 elements in total -- such as 9 heavy metal elements, lead (Pb), cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), zinc (Zn), iron (Fe), arsenic (As) and mercury (Hg), AND metal element of aluminum (Al), through the inductively coupled plasma atomic emission spectrometer.

This Standard is applicable to the determination of the heavy metal's content in latex products.

2 Normative references

The following documents are essential to the application of this document. For the dated documents, only the versions with the dates indicated are applicable to this document; for the undated documents, only the latest version (including all the amendments) are applicable to this Standard.

GB/T 6682 Water for analytical laboratory use - Specification and test methods

3 Principle

After the samples go through the microwave digestion, set the digestion solution to the constant volume. Use the inductively coupled plasma atomic emission spectrometer to determine the concentration of 9 heavy metal elements which are the lead (Pb), cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), zinc (Zn), iron (Fe), arsenic (As) and mercury (Hg), AND metal element of aluminum (Al); calculate the content of metal in the sample.

Firstly, prepare the standard solutions of the 10 metal elements which require to be tested.

Mercury standard solution shall be separately prepared; it can use mixed standard solution for copper, cadmium, chromium, lead, arsenic, manganese, iron, aluminum and zinc, or they can be prepared separately. The validity period of the prepared standard solution after dilution is one month. Take 6 points at the standard curve (including the calibration blank).

Under the condition that the linear correlation coefficient is not less than 0.995, the concentration of the standard solution can be adjusted according to actual needs. Under the condition that the baseline of the instrument is relatively stable, inject the standard solution; determine it for three times continuously; measure the corresponding peak area; then inject the sample solution; determine it for three times continuously; measure the corresponding peak area.

6 Measurement procedure

7 Result calculation

The content (Xi) of the element in the sample shall be calculated according to the formula (1). Where.

Xi - the content of the element "i" in the sample. The unit is milligram per kilogram (mg/kg); c - the mass concentration of the element in the sample solution which is obtained from the standard working curve. The unit is milligram per liter (mg/L); c0 - the mass concentration of the element in the blank solution which is obtained from the standard working curve. The unit is milligram per liter (mg/L);

V - the constant volume of the test solution. The unit is milliliter (mL); m - the sample mass. The unit is gram (g).

Take the arithmetic mean value of the parallel measurement results of two samples as the sample test result; the calculation result shall retain 1 decimal place. The absolute difference of the two independent determination results obtained under the repeatability condition does not exceed 10% of its arithmetic mean. […]