HJ 776-2015Water quality. Determination of 32 elements. Inductively coupled plasma optical emission spectrometry (English PDF)

3.1 Soluble elements

The acid content of the sample after filtration through the 0.45 µm filter.

3.2 Total elements

The unfiltered sample, the content of the element measured after digestion.

5.1 Spectral interference

Spectral disturbances mainly include continuous background and overlapping interference. The current correction method is the background subtraction method (according to the single element and the mixed element test to determine the location and manner of subtracting the background) and the interference coefficient method. Basics can also be used in mixed standard solutions to eliminate its effects.

When there is a single element interference, the interference factor can be obtained according to the following formula.

QQK) '(- =

Where tK - interference coefficient;

'Q - interference element plus analysis element content;

Q - analysis of the content of elements;

TQ - the content of interfering elements.

By preparing a series of solutions containing a known amount of interfering elements, the 'Q is determined at the position of the wavelength of the element, and the formula TK, and then manual deduction or computer automatic deduction.

Under normal circumstances, surface water, groundwater samples due to low element concentration, spectral and inter-element interference between the general circumstances can ignore. Industrial wastewater and other common target elements to determine the wavelength spectrum interference see Appendix B. Note that the interferometric coefficients for different instruments are different.

5.2 Non-spectral interference

Non-spectral interference mainly includes chemical interference, ionization interference, physical interference and solvent interference, etc., in the actual analysis of various types of Interference is difficult to separate. Whether it is compensated and corrected, and the concentration of interfering elements in the sample. In addition, the physical interference is generally the same the degree of stickiness and surface tension of the product changes, especially when the sample contains a large number of soluble salts or samples of acidity is too high, Health interference. The easiest way to eliminate such interference is to dilute the sample. But should ensure that the content of the measured element is higher than the lower limit of determination.

6.14 Sodium hydroxide solution. rho (NaOH) = 100 g/L

Weigh 100 g sodium hydroxide (6.5) dissolved in the amount of water, dissolved after adding water to the volume of 1000 ml, shake.

6.15 Standard solution

6.15.1 Single element standard stock solution.

Silver (Ag), aluminum (Al), arsenic (As), boron (B), barium (Ba), beryllium (Be), bismuth (Bi), calcium (Ca), cadmium (Cd) (Fe), iron (Fe), iron (Fe), potassium (K), lithium (Li), magnesium (Mg), manganese (Mn), molybdenum (Mo) (Sn), strontium (Sr), titanium (Ti), titanium (Ni), phosphorus (P), lead (Pb), sulfur (S), antimony (Sb), selenium (Se), silicon (Si) And Vanadium (V), zinc (Zn) and zirconium (Zr) at a concentration of 1000 mg/L or 100 mg/L. From the purchase or purchase of commercially available standard solution.

6.15.1.1 Silver (Ag). rho = 1000 mg/L.

Weigh 1.0000 g (accurate to 0.0001 g) of metallic silver (pure spectrum), dissolved in 25 ml nitric acid (6.1) and cooled.

Apply water to 1 L.

6.15.1.2 Aluminum (Al). rho = 1000 mg/L.

Weigh 1.0000 g (accurate to 0.0001 g) metal aluminum (pure spectrum), dissolved in 150 ml hydrochloric acid solution (6.9), boiled, After cooling, use experimental water to set to 1 L.

6.15.1.3 arsenic (As). rho = 1000 mg/L.

Weigh 1.3203 g (accurate to 0.0001 g) arsenic trioxide (As2O3), dissolve with 20 ml of sodium hydroxide solution (6.14) Diluted with an appropriate amount of water, neutralized with hydrochloric acid (6.2) to a pH of about 6, and fixed to 1 L with experimental water.

6.15.1.4 Boron (B). rho = 1000 mg/L.

Weigh 5.7192 g (accurate to 0.0001 g) boric acid (H3BO3) dissolved in a small amount of water, with the experimental water volume to 1 L.

6.15.1.5 Barium (Ba). rho = 1000 mg/L.

Weigh 1.5163 g (accurate to 0.0001 g) anhydrous barium chloride (BaCl2, 250 ° C for 2 h), washed with 20 ml of nitric acid solution (6.7) Dissolved, with the experimental water volume to 1 L.

6.15.1.6 Beryllium (Be). rho = 100 mg/L.

Weigh 0.1000 g (accurate to 0.0001 g) metal beryllium (pure spectrum), dissolved in 150 ml hydrochloric acid solution (6.9), and after cooling with the experimental water volume to 1 L.

6.15.1.7 Bi (Bi). rho = 1000 mg/L.

Weigh 1.0000 g (accurate to 0.0001 g) metal bismuth (pure spectrum) and dissolve with 50 ml nitric acid solution (6.7) until completely Dissolved and cooled to room temperature, with the experimental water volume to 1 L.

6.15.1.8 Calcium (Ca). rho = 1000 mg/L.

Weigh 2.4972 g (accurate to 0.0001 g) of calcium carbonate (CaCO3, 1, 10 °C for 1 h), dissolved in 20 ml of water, add 10 ml Hydrochloric acid (6.2) to complete dissolution, boil to remove CO2, after cooling with experimental water to volume 1L.

6.15.1.9 Cadmium (Cd). rho = 1000 mg/L.

Weigh 1.0000 g (accurate to 0.0001 g) metal cadmium (pure spectrum), dissolved in 30 ml nitric acid (6.1), with the experimental water volume to 1 L.

6.15.1.10 cobalt (Co). rho = 1000 mg/L.

Weigh 1.0000 g (accurate to 0.0001 g) metal cobalt (spectrum purity), dissolved in 50 ml nitric acid solution (6.7), cooled and cooled with the experimental water volume to 1 L.

6.15.1.11 Chromium (Cr). rho = 1000 mg/L.

Weigh 1.0000 g (accurate to 0.0001 g) of metal chromium (pure spectrum), dissolved in 30 ml hydrochloric acid solution (6.9), cooled and cooled with the experimental water volume to 1 L.

6.15.1.12 Copper (Cu). rho = 1000 mg/L.

Weigh 1.0000 g (accurate to 0.0001 g) of metallic copper (pure spectrum), dissolved in 30 ml nitric acid solution (6.7), cooled and cooled with the experimental water volume to 1 L.

6.15.1.13 Iron (Fe). rho = 1000 mg/L.

Weigh 1.0000 g (accurate to 0.0001 g) of metallic iron (pure spectrum), dissolved in 150 ml hydrochloric acid solution (6.9), cooled with solid Apply water to 1 L.

6.15.1.14 Potassium (K). rho = 1000 mg/L.

Weigh 1.9067 g (accurate to 0.0001 g) potassium chloride (KCl, at 400 ° C to 450 ° C until no burst) Dissolve and set to 1 L.

6.15.1.15 Lithium (Li). rho = 1000 mg/L.

Weigh 5.3240 g (accurate to 0.0001 g) lithium carbonate (Li2CO3, bake at 105 ° C for 1 h), add 20 ml of hydrochloric acid solution (6.9) to complete dissolution, with the experimental water volume to 1 L.

6.15.1.16 Magnesium (Mg). rho = 1000 mg/L.

Weigh 1.0000 g (accurate to 0.0001 g) of metallic magnesium (pure spectrum), add 30 ml of water, slowly add 30 ml of hydrochloric acid (6.2) to completely dissolved, boiled, cooled with experimental water to volume to 1 L.

6.15.1.17 Mn (Mn). rho = 1000 mg/L.

Weigh 1.0000 g (accurate to 0.0001 g) of metal manganese (pure spectrum), dissolved in 30 ml hydrochloric acid solution (6.9), after cooling with the experimental water volume to 1 L.

6.15.1.18 Molybdenum (Mo). rho = 1000 mg/L.

Weigh 1.7325 g (accurate to 0.0001 g) ammonium molybdate [(NH4) 6Mo7O24 - 4H2O], dissolved in experimental water and allowed to settle to 1 L.

6.15.1.19 Sodium (Na). rho = 1000 mg/L.

Weigh 2.5421 g (accurate to 0.0001 g) of sodium chloride (NaCl, at 400 ° C to 450 ° C until no burst) Dissolved in water and set to 1 L.

6.15.1.20 Nickel (Ni). rho = 1000 mg/L.

Weigh 1.0000 g (accurate to 0.0001 g) of metallic nickel (pure spectrum), dissolved with 30 m1 nitric acid solution (6.7), cooled and cooled with the experimental water volume to 1 L.

6.15.1.21 Phosphorus (P). rho = 1000 mg/L.

Weigh 4.3935 g (accurate to 0.0001 g) potassium dihydrogen phosphate (KH2PO4, bake at 110 ° C for 2 h), dissolve with the test water and set to 1 L.

6.15.1.22 Lead (Pb). rho = 1000 mg/L.

Weigh 1.0000 g (accurate to 0.0001 g) metal lead (pure spectrum), dissolve with 30 m1 nitric acid solution (6.7), after cooling with the experimental water volume to 1 L.

6.15.1.23 sulfur (S). rho = 1000 mg/L.

Weigh 4.4303 g (accurate to 0.0001 g) sodium sulfate (Na2SO4, bake at 105 ° C for 1 h) or weigh 5.4352 g (accurate to 0.0001 G) potassium sulfate (K2SO4, 105 °C baking 1 h), with 10 ml hydrochloric acid solution (6.11) dissolved, with the experimental water volume to 1 L.

6.15.1.24 Antimony (Sb). rho = 1000 mg/L.

Weigh 1.0000 g (accurate to 0.0001 g) metal antimony (spectrum purity), with 20 m1 ~ 30 m1 sulfuric acid solution (6.12) heating completely Dissolved, with sulfuric acid solution (6.13) constant volume to 1L.

6.15.1.25 Selenium (Se). rho = 1000 mg/L.

Weigh 1 million (accurate to 0.0001 g) selenium (pure spectrum), add 20 m1 ~ 30 ml hydrochloric acid solution (6.9), water bath heating solution Solution, drop a few drops of nitric acid (6.1) to complete dissolution, cooling with experimental water to volume to 1 L.

6.15.1.26 Si (Si). rho (SiO2) = 1000 mg/L.

2.9640 g (0.0001 g) ammonium hexafluorosilicate [(NH4) 2SiF6] was weighed and heated to.200 ° C hydrochloric acid solution (6.11) at low temperature all dissolved, cooled with experimental water volume to 1 L.

6.15.1.27 Tin (Sn). rho = 1000 mg/L.

Weigh 1.0000 g (accurate to 0.0001 g) tin (pure spectrum), add 50 m1 hydrochloric acid solution (6.9), dissolve in water bath, cold but then add 80 m1 hydrochloric acid (6.2), with the experimental water volume to 1 L.

6.15.1.28 Strontium (Sr). rho = 1000 mg/L.

Weigh 1.6848 g (accurate to 0.0001 g) strontium carbonate (SrCO3, 105 ° C for 1 h) and dissolve in 60 ml hydrochloric acid solution (6.9) and boiled, cooled with experimental water to volume to 1 L.

6.15.1.29 Titanium (Ti). rho = 1000 mg/L.

Weigh 1.0000 g (accurate to 0.0001 g) metal titanium (pure spectrum), dissolved in 100 m1 hydrochloric acid solution (6.9), cooled and cooled and fixed to 1 L with hydrochloric acid solution (6.9).

6.15.1.30 Vanadium (V). rho = 1000 mg/L.

Weigh 2.2957 g (accurate to 0.0001 g) of ammonium metavanadate (NH4VO3) and heated to complete dissolution with 10 ml nitric acid (6.1) Experimental water volume to 1 L.

6.15.1.31 zinc (Zn). rho = 1000 mg/L.

Weigh 1.0000 g (accurate to 0.0001 g) of metal zinc (pure spectrum), dissolved with 40 ml of hydrochloric acid (6.2), boiled and cooled with Experimental water volume to 1 L.

6.15.1.32 Zirconium (Zr). rho = 1000 mg/L.

Weigh 3.5328 g (0.0001 g) of zirconium chloride (ZrOCl2 · 8H2O) with 40 ml to 50 ml of hydrochloric acid solution (6.10) to Completely dissolved and fixed to 1 L with hydrochloric acid solution (6.10).

6.15.2 Single element standard use liquid.

Remove the single element standard stock solution (6.15.1) dilution preparation separately. Diluted with a certain amount of nitric acid (6.7), so that the standard use of liquid of nitric acid content of 1%.

6.15.3 Multi-element mixed standard solution.

According to the interference between the elements of the situation and the nature of the standard solution of the preparation, the concentration should be based on the analysis of samples and elements to be determined, the acidity of the standard solution to keep the sample to be measured consistent with the acidity, are 1% nitric acid. Multi-element mixed standard solution grouping is shown in Table 1.

Table 1 Multi-element mixed standard solution grouping table

Grouping elements

1 Mo, Ag

3 V, Ti

Al, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Li, K, Mg, Mn, Na, Ni, Pb, Sr, Zn, Zr

5 As, Bi, Sb, Se, Sn

8.1 Collection and storage of samples

The collection of water samples is carried out in accordance with the relevant provisions of HJ/T 91 and HJ/T 164. Before sampling, wash the polyethylene bottle with detergent and water, Placed in nitric acid solution (6.7) soak for more than 24 h, with the experimental water thoroughly washed. If the soluble element is determined, the sample is collected immediately after passage (6.16), discard the initial 50 ml ~ 100 ml filtrate, collect the required volume of the filtrate, add the appropriate amount of nitric acid (6.1), add the appropriate amount of nitric acid (6.1) So that the nitric acid content of 1%. Such as the total amount of elements measured, immediately after the collection of samples by adding nitric acid (6.1), the nitric acid content of 1%.

8.2 Preparation of the sample

8.2.1 Determination of soluble elements

See 8.1 for sample handling.

8.2.2 Determine the total amount of elements

A nitric acid solution (6.7) was added in proportion to a uniform volume of sample, usually 100 ml of sample was added to 5.0 ml of nitric acid (6.7).

Placed on the hot plate heating digestion, in the case of non-boiling, slowly heated to near dry. Remove the cooling and repeat this process until the sample solution is light or stable. After cooling, add nitric acid (6.7) a few milliliters, add a small amount of water, set on the hot plate to continue the residue is dissolved by heating. After cooling, the volume of the original sample is set with the experimental water to keep the solution at 1% (v/v) nitric acid. For some Basically complex waste water, digestion can be added 2 ml ~ 5 ml perchloric acid (6.4) digestion. If there is some insoluble in the digestion solution, can be standing or centrifuged at 2000 rpm to 3000 rpm for 10 min to obtain a clear solution. (If there is still suspended after centrifugation or standing overnight, it can be filtered to remove, but should avoid possible contamination during filtration. )

Note 1. water digestion can be used according to HJ 678 microwave digestion method.

Note 2. When the target element content is high, should take appropriate amount of digestion solution diluted with 1% nitric acid solution.

8.2.3 Preparation of blank samples

The sample was prepared in the same manner as in the preparation of the sample (8.2.2) with water instead of the sample.

9.1 Instrument reference test conditions

Different models of the best test conditions of different instruments, according to the instrument specification requirements to optimize the test conditions. The instrument reference measurement conditions are shown in Table 2.

Table 2 Instrument analysis of the main indicators recommended reference conditions

Observe the horizontal, vertical or horizontal vertical use Transmit power 1150 W Carrier gas flow rate 0.7 L/min Auxiliary air flow 1.0 L/min the cooling gas flow rate is 12.0 L/min

9.2 Calibration curve calibration

Take a certain amount of single element standard use of liquid (6.15.2) to prepare the calibration curve, according to the surface water and wastewater concentration range of the preparation, in the respective concentration range, at least 5 concentration points were prepared. Surface water, groundwater calibration curve reference concentration range in Table 3, wastewater the calibration curve for the determination of the reference concentration range is shown in Table 4. From low to high concentrations followed by injection, according to the instrument reference test conditions (9.1) measurements Emission intensity. With the emission intensity value as the ordinate, the target element series mass concentration is the abscissa, and the calibration curve of the target element is established.

Table 3 Surface water, groundwater standard solution concentration range

Element concentration range (mg/L) Al, Sr, P 0.00 to 5.00 Ba, Fe 0.00 to 2.00 be, Cd, Mo, Ag 0.00 to 0.50 B, Co, Cr, Cu, Li, Mn, Ni, Pb, Zn 0.00 to 1.00 V, Ti 0.00 to 1.00 Ca, Si 0.00 to 50.00 Mg, Na, K 0.00 to 10.00

Table 4 Wastewater Standard Solution Concentration Range

Element concentration range (mg/L) Ag, Al *, B, Ba *, Be, Bi, Ca *, Cd, Co, Cr, Cu, Fe *, K *, Li *, Mg, Mn, Na *, Ni, Pb, S, Sr, Zn, Zr 0.00 ~ 250.00 * 0.00 to 500.00 P 0.00 to ...