GB/T 34208-2017Iron and steel—Determination of antimony and tin content—Inductively coupled plasma atomic emission spectrometric method (English PDF)

4.5 Antimony stock solution, 500 µg/mL

Weigh 1.371 5 g of antimony potassium tartrate (C4H4KOSb· H2O) pre-dried in a desiccator; dissolve in hydrochloric acid (1 + 9); transfer to a 1,000 mL volumetric flask; use hydrochloric acid (1 + 9) to dilute to scale; mix up.

1 mL of the solution contains 500 µg of antimony. A merchant certified antimony standard solution can also be used.

4.5.1 Antimony standard solution, 10.0 µg/mL

Transfer 2.00 mL of antimony stock solution (4.5.1) to a 100 mL volumetric flask; use hydrochloric acid (1 + 9) to dilute to scale; mix up.

1 mL of the solution contains 10.0 µg of antimony.

4.5.2 Tin standard solution

4.6 Tin standard solution

4.6.1 Tin stock solution, 500 µg/mL

Weigh 0.500 0 g of high-purity tin (mass fraction not less than 99.9%); place into a 200 mL beaker. Add 40 mL of hydrochloric acid (1 + 1); heat to dissolve. After cooling to room temperature, transfer the solution into a 1,000 mL volumetric flask; use hydrochloric acid to dilute to scale; mix up.

1 mL of the solution contains 500 µg of tin. A merchant certified antimony standard solution can also be used.

4.6.2 Tin standard solution, 10.0 µg/mL

Spray in blank test solutions for about 10 s; measure 10 times using the preset integral time.

Spray in 10 times detection limit solutions about 10 s; measure 10 times using the preset integral time.

Based on the readings of intensity obtained from blank solutions and 10 times detection limit solutions, calculate the average intensity of blank solutions X b, the average intensity of 10 times detection limit solutions X1 and the standard deviation of blank sb.

Calculate the net average intensity of 10 times detection limit solutions (X n1) in accordance with Equation (A.1).

Calculate the detection limit of tested elements (DL) in accordance with Equation (A.2). where. rho 1 - the concentration of 10 times detection limit solutions, in µg/mL;

It shall be indicated that, because of limited number of repeated measurements, the errors of detection limit calculated using this method are within a wide range.

A.2.3 Determination of background equivalent concentration

Calculate the background equivalent concentration (BEC) in accordance with Equation (A.3).

A.3 Spectral line interferences

Spectral line inferences make the intensities of tested elements' analytical lines on the high side, so spectral interference calibration needs to be done.

Prepare respectively one solution containing 1 mg/L of tested elements and one solution containing 1,000 mg/L of interfering elements.

Spray in respectively water, 1 mg/L tested element solution and 1,000 mg/L interfering element solution; measure the absolution intensities of the tested elements' analytical lines.

Obtain the net analytical intensity In by subtracting the absolute intensity of 1 mg/L tested element solution by the intensity of water. […]