GB/T 15454-1995 Determination of sodium, ammonium, potassium, magnesium and calcium ions in industrial circulating cooling water - Ion chromatography
Some standard content:
National Standard of the People's Republic of China
Determination of sodium, ammonium, potassium, magnesium and calcium ions in industrial circulating cooling water, ion chromatography
Industrial circulating cooling water---Determinationof sodium,ammonium, potassium, magnesium andcalcium--Ions chromatography1 Subject content and applicable scope
GB/T 15454—95
This standard specifies the method for determining the contents of Na, NHt, K+, Mg2+ and Ca2+ in industrial circulating cooling water. This standard is applicable to the determination of Na content in the range of 1.00~50.0mg/L, NH+ content in the range of 1.00~30.0mg/L, K+ content in the range of 1.00~50.0mg/L, Mg2+ content in the range of 1.00~50.0mg/L and Ca2+ content in industrial circulating cooling water. If it exceeds this range, it can be diluted and determined within this range. This standard is also applicable to the determination of Na+, NHt, K+, Mg2+ and Ca2+ content in surface water, groundwater and other industrial water. 2 Reference standards
GB/T602 Preparation of standard solutions for determination of impurities in chemical reagents GB/T6682 Specifications and test methods for water used in analytical laboratories 3 Terminology
3.1 Eluent
Ionic mobile phase used to transport samples through ion separation columns. 3.2 Stationary phase
The substance that does not move in the chromatographic column and has a separation effect. 3.3 Resolution
The ability of the chromatographic column to separate continuous components.
3.4 Chromatogram
The concentration of each component eluted from the separation column is continuously recorded, and the elution time is plotted to obtain a chromatographic elution curve, which is a chromatogram. 3.5 Peak height
The vertical distance between the highest point of the peak and the baseline. 3.6 Retention time
The time difference between injection and the appearance of each peak height is called retention time. 4 Method Summary
Ions have different distribution coefficients between the stationary phase and the mobile phase. When the mobile phase brings the sample to the separation column, the ions in the sample are separated due to the different relative affinities of various ions to the ion exchange resin. Then it flows through the conductivity cell and is detected by the conductivity detector, and a chromatogram of each ion is drawn. The retention time is used for qualitative analysis and the peak area or peak height is used for quantitative analysis to measure the ion content. Approved by the State Administration of Technical Supervision on January 12, 1995 and implemented on October 1, 1995
5 Reagents and Materials
GB/T 15454--95
The water used in this standard shall meet the specifications of secondary water in GB6682 and be degassed. The reagents used are all high-grade pure reagents unless otherwise specified.
5.1 Reagents and Materials for Determination of Sodium, Ammonium and Potassium Ions: 5.1.1 Sodium Ion Standard Stock Solution: Na+ concentration is 1000mg/L. Weigh 2.542g of sodium chloride (GB/T1266) burned to constant weight at 500-600℃, dissolve in water, transfer to a 1000mL volumetric flask, dilute to scale with water, shake well. Store in a polyethylene bottle and place in a refrigerator (4℃). 5.1.2 Ammonium ion standard stock solution: The concentration of NHt is 1000mg/L. Weigh 2.966g of ammonium chloride (GB/T658) dried to constant weight at 105-110℃, dissolve in water, transfer to a 1000mL volumetric flask, dilute to scale with water, shake well, store in a polyethylene bottle and place in a refrigerator (4℃). 5.1.3 Potassium ion standard stock solution: The concentration of K+ is 1000mg/L. Weigh 1.907g of potassium chloride (GB/T646) burned to constant weight at 500-600℃, dissolve in water, transfer to a 1000mL volumetric flask, dilute to scale with water, and shake well. Store in a polyethylene bottle and place in a refrigerator (4℃). 5.1.4 Standard stock solution for ion chromatography: Take 2.00mL of sodium ion standard stock solution (5.1.1), 4.00mL of ammonium ion standard stock solution (5.1.2), and 4.00mL of potassium ion standard stock solution (5.1.3) in a 100mL volumetric flask, dilute to scale with water, and shake well. Store in a polyethylene bottle and place in a refrigerator (4℃). 5.1.5 Standard working solution for ion chromatography: Transfer 10.00mL of standard stock solution for ion chromatography (5.1.4) to a 50mL volumetric flask, dilute to scale with water, and shake well. The concentrations of Na+, NH+, and K+ in this solution are 4.00 mg/L, 8.00 mg/L, and 8.00 mg/L, respectively. 5.1.6 Eluent and regeneration solution for determination of sodium, ammonium, and potassium ions: Prepare according to the instructions of the separation column and the suppression column. 5.2 Reagents and materials for determination of calcium and magnesium ions: 5.2.1 Standard stock solution of magnesium ions: The concentration of Mg2+ is 1000 mg/L. Weigh 1.657 g of magnesium oxide (GB/T9857) burned to constant weight at 800°C into a 100 mL beaker, moisten with water, add hydrochloric acid (GB/T622) dropwise until dissolved, then add 2.5 mL of hydrochloric acid in excess, transfer to a 1000 mL volumetric flask, dilute with water to the mark, and shake well. Store in a polyethylene bottle and place in a refrigerator (4°C).
5.2.2 Standard stock solution of calcium ions: The concentration of Ca2+ is 1000 mg/L. Weigh 2.497g of calcium carbonate dried to constant weight at 105-110℃ into a 100mL beaker, moisten with water, add hydrochloric acid (GB/T622) dropwise until dissolved, then add 2.5mL of excess hydrochloric acid, transfer to a 1000mL volumetric flask, dilute to scale with water, and shake to mix. Store in a polyethylene bottle and place in a refrigerator (4'℃).
5.2.3 Standard stock solution for ion chromatography determination: Take 2.00mL of magnesium ion standard stock solution (5.2.1) and 4.00mL of calcium ion standard stock solution (5.2.2) into a 100mL volumetric flask, dilute to scale with water, and shake well. Store in a polyethylene bottle and place in a refrigerator (4℃). 5.2.4 Standard working solution for ion chromatography determination: Transfer 5.00mL of ion chromatography determination standard stock solution (5.2.3) into a 50mL volumetric flask, dilute to scale with water, and shake well. The concentrations of Mg2+ and Ca2+ in this solution are 2.00mg/L and 4.00mg/L respectively. 5.2.5 Eluent and regeneration solution for magnesium and calcium ion determination: Prepare according to the requirements of separation column and inhibition column. 5.3 Medium-speed qualitative filter paper.
6 Instruments and equipment
General laboratory instruments and
6.1 Ion chromatograph (RSD<3%);
6.2 Syringe: minimum capacity 2mL;
GB/T 15454—95
6.3 Recorder: response time <2s (or integrator, microcomputer), 6.4 Cation separation column and guard column or cation separation column, guard column and inhibition column; 6.5 Refrigerator (10℃).
7 Selection of chromatographic conditions
According to the optimal conditions provided in the instrument and chromatographic column manual, adjust the eluent flow rate, the output range of the conductivity detector, the paper feed speed of the recorder and the signal size millivolt range. Samples can be injected only after the baseline is stable. 8 Preparation of sample solution
Take a water sample on site, filter it through a medium-speed qualitative filter paper (5.3), and use a pipette to take 20mL of the filtered water sample (the sampling volume can be appropriately increased or decreased depending on the content of Na+, NH+, K+, Mg2+ and Ca2+ in the water), transfer it to the pretreatment column, and let it flow through the pretreatment column (see Appendix A). Rinse the pretreatment column and resin bed with 60mL of deionized water for 6 times. Collect the water sample and the washing solution into a 100mL volumetric flask, dilute with water to the scale, and shake well.
9 Determination
9.1 Determination of sodium, ammonium and potassium ion content
Turn on the machine, use Na+, NHt, K+ separation column, wait until the baseline is stable after washing with Na+, NHt, K+ eluent (5.1.6), start to add standard working solution (5.1.5) to obtain a standard spectrum; then add water sample (8) to obtain a spectrum. If necessary, rinse the separation column and turn off the machine. 9.2 Determination of magnesium and calcium ion content
Turn on the machine, use Mg2+, Ca2+ separation column, wait until the baseline is stable after washing with Mg2+, Ca2+ eluent (5.2.5), start to add standard working solution (5.2.4) to obtain a standard spectrum; then add water sample (8) to obtain a spectrum. If necessary, rinse the separation column and turn off the machine. 10 Expression of analysis results
The content z of the ion to be measured expressed in mg/L is calculated according to formula (1): V.
Where: L—peak height of the measured ion in the water sample, mm; L—peak height of the measured ion in the standard working solution, mm; co-concentration of the measured ion in the standard working solution, mg/L; V-—volume of the water sample taken, mL;
V.The volume of the water sample after dilution.
(1)
Or the chromatographic microprocessor directly calculates the result according to the peak area or peak height. Note: L/L. It should be between 0.5 and 2. If L/L>2, dilute the water sample (see Chapter 8) and then measure it. If L/L<0.5, dilute the standard solution and then measure it.
GB/T15454-95
Appendix·A
Filling of pretreatment column
(Supplement)
Since scale inhibitors, corrosion inhibitors and bactericides are added to the cooling water, especially organic matter containing benzene rings, it permanently adsorbs the resin of the separation column, reducing the adsorption capacity of the separation column and even damaging the column. Therefore, the water sample should be pretreated without affecting the determination of the measured ions to eliminate its influence on the determination. Use porous adsorption resin to pretreat the water sample. A1 Reagents and solutions
A1.1 Hydrochloric acid methanol solution
Pour 200mL hydrochloric acid (GB/T622) into 200mL methanol (GB/T683) and mix well. A1.2 Hydrochloric acid methanol solutionWww.bzxZ.net
Pour 50mL hydrochloric acid (GB/T622) into 450mL methanol (GB/T683) and mix well. A2 Filling of pretreatment column
A2.1 Resin pretreatment
The adsorption resin (Y×A05, 300m) is treated by the following steps before column loading: soak in acetone (GB/T686) for 1d, drain, soak in hydrochloric acid methanol solution (A1.1) for 2~3h, filter, wash with methanol (GB/T683), and wash with water until there is no chloride ion; A2.2 Column loading
The pretreatment column tube can be modified from a general burette. When loading the column, add a small group of polyolefin fiber at the bottom of the column, wet-load the adsorption resin (Y×A05, 300m) to a height of about 15cm, and wash the pretreatment column with deionized water until there is no chloride ion in the effluent. The pretreatment column can continuously process samples. Usually, after about one month of use, it is washed with hydrochloric acid methanol solution (A1.2), and then washed with deionized water until there is no nitrogen ion and can be used again. Appendix B
Deionized water degassing
(Supplement)
Deionized water usually contains dissolved gas. If the eluent is prepared directly, the dissolved gas will cause the eluent to short-circuit, making the baseline unstable during the process of flushing and balancing the separation column, affecting the normal measurement, and even damaging the separation column in severe cases. Therefore, before preparing the eluent, the deionized water must be degassed first. B1 Instruments and Equipment
B1.1 Vacuum Pump;
B1.2 Suction Filter Bottle: 2.5L.
B2 Deionized Water Degassing
Put the deionized water into the clean suction filter bottle, then connect the vacuum pump, cover the suction filter bottle tightly, turn on the vacuum pump, and degas for 10 minutes. During the degassing process, gently shake the suction filter bottle to ensure complete degassing. But be careful not to suck water back into the vacuum pump. 546
C1 Reagents and materials
GB/T 15454—95
Appendix C
Simultaneous determination of sodium, ammonium, potassium, magnesium and calcium ions (for use in units equipped with separation columns for simultaneous determination of Na+, NH+, K+, Mg2+ and Ca+) (reference)
C1.1 Standard stock solutions for ion chromatography Pipette 4.00 mL of sodium ion standard stock solution (5.1.1), 10.00 mL of ammonium ion standard stock solution (5.1.2), 10.00 mL of potassium ion standard stock solution (5.1.3), 5.00 mL of magnesium ion standard stock solution (5.2.1) and 10.00 mL of calcium ion standard stock solution (5.2.2) into a 100 mL volumetric flask, dilute to the mark with water and shake well. Store in a polyethylene bottle and place in a refrigerator (4°C). C1.2 Standard working solution for ion chromatography Pipette 10.00 mL of the standard stock solution for ion chromatography (C1.1) into a 100 mL volumetric flask, dilute to the mark with water, and shake well. The concentrations of Na+, NHt, K+, Mg2+, and Ca2+ in this solution are 4.00 mg/L, 10.00 mg/L, 10.00 mg/L, 5.00 mg/L, and 10.00 mg/L, respectively.
C1.3 Eluent, regeneration solution
Prepare according to the instructions for use of the separation column and suppression column. C2 Instruments and equipment
General laboratory instruments and
C2.1 Ion chromatograph (RSD<3%);
C2.2 Syringe: minimum capacity 1mL;
C2.3 Recorder: response time <2s, (or integrator, microcomputer); C2.4 High-efficiency cation separation column, suppression column and guard column for the one-time determination of Na+, NH+, K+, Mg2+ and Ca2+. C3 Selection of chromatographic conditions
According to the optimal conditions provided in the instrument and chromatographic column manual, adjust the eluent flow rate, conductivity detector output range, recorder paper feed speed and signal size millivolt range, and inject samples only after the baseline is stable. C4 Preparation of sample solution
Same as Chapter 8 of this standard.
C5 Simultaneous determination of sodium, ammonium, potassium, magnesium and calcium ions Turn on the machine, balance the separation column (C2.4) with the eluent (C1.3), wait for the baseline to stabilize, start to introduce the standard working solution (C1.2) to obtain the standard spectrum; then introduce the water sample (C4) to obtain the spectrum. If necessary, rinse the separation column and turn off the machine. C6 Expression of analysis results
Same as Chapter 10 of this standard.
Additional instructions:
GB/15454—95
This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Tianjin Chemical Research Institute of the Ministry of Chemical Industry. This standard was drafted by the Tianjin Chemical Research Institute of the Ministry of Chemical Industry and the Beijing Institute of Mineral Geology. The main drafters of this standard are Shao Weiren, Jiang Renyi, Zhang Yanli, Wang Kejuan and Zhu Chuanjun. This standard adopts the "Method 300.7 - Chemical Suppression Ion Chromatography for Determination of Sodium, Ammonium, Potassium, Magnesium and Calcium Dissolved in Precipitation" of the Development and Research Center and Environmental Monitoring Laboratory of the United States Environmental Protection Agency.5L.
B2 Deionized water degassing
Put deionized water into a clean suction filter bottle, then connect the vacuum pump, cover the suction filter bottle tightly, turn on the vacuum pump, and degas for 10 minutes. During the degassing process, gently shake the suction filter bottle to ensure complete degassing. But be careful not to let the water be sucked back into the vacuum pump. 546
C1 Reagents and materials
GB/T 15454—95
Appendix C
Simultaneous determination of sodium, ammonium, potassium, magnesium and calcium ions (for use in units equipped with separation columns for simultaneous determination of Na+, NH+, K+, Mg2+ and Ca+) (reference)
C1.1 Standard stock solutions for ion chromatography Pipette 4.00 mL of sodium ion standard stock solution (5.1.1), 10.00 mL of ammonium ion standard stock solution (5.1.2), 10.00 mL of potassium ion standard stock solution (5.1.3), 5.00 mL of magnesium ion standard stock solution (5.2.1) and 10.00 mL of calcium ion standard stock solution (5.2.2) into a 100 mL volumetric flask, dilute to the mark with water and shake well. Store in a polyethylene bottle and place in a refrigerator (4°C). C1.2 Standard working solution for ion chromatography Pipette 10.00 mL of the standard stock solution for ion chromatography (C1.1) into a 100 mL volumetric flask, dilute to the mark with water, and shake well. The concentrations of Na+, NHt, K+, Mg2+, and Ca2+ in this solution are 4.00 mg/L, 10.00 mg/L, 10.00 mg/L, 5.00 mg/L, and 10.00 mg/L, respectively.
C1.3 Eluent, regeneration solution
Prepare according to the instructions for use of the separation column and suppression column. C2 Instruments and equipment
General laboratory instruments and
C2.1 Ion chromatograph (RSD<3%);
C2.2 Syringe: minimum capacity 1mL;
C2.3 Recorder: response time <2s, (or integrator, microcomputer); C2.4 High-efficiency cation separation column, suppression column and guard column for the one-time determination of Na+, NH+, K+, Mg2+ and Ca2+. C3 Selection of chromatographic conditions
According to the optimal conditions provided in the instrument and chromatographic column manual, adjust the eluent flow rate, conductivity detector output range, recorder paper feed speed and signal size millivolt range, and inject samples only after the baseline is stable. C4 Preparation of sample solution
Same as Chapter 8 of this standard.
C5 Simultaneous determination of sodium, ammonium, potassium, magnesium and calcium ions Turn on the machine, balance the separation column (C2.4) with the eluent (C1.3), wait for the baseline to stabilize, start to introduce the standard working solution (C1.2) to obtain the standard spectrum; then introduce the water sample (C4) to obtain the spectrum. If necessary, rinse the separation column and turn off the machine. C6 Expression of analysis results
Same as Chapter 10 of this standard.
Additional instructions:
GB/15454—95
This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Tianjin Chemical Research Institute of the Ministry of Chemical Industry. This standard was drafted by the Tianjin Chemical Research Institute of the Ministry of Chemical Industry and the Beijing Institute of Mineral Geology. The main drafters of this standard are Shao Weiren, Jiang Renyi, Zhang Yanli, Wang Kejuan and Zhu Chuanjun. This standard adopts the "Method 300.7 - Chemical Suppression Ion Chromatography for Determination of Sodium, Ammonium, Potassium, Magnesium and Calcium Dissolved in Precipitation" of the Development and Research Center and Environmental Monitoring Laboratory of the United States Environmental Protection Agency.5L.
B2 Deionized water degassing
Put deionized water into a clean suction filter bottle, then connect the vacuum pump, cover the suction filter bottle tightly, turn on the vacuum pump, and degas for 10 minutes. During the degassing process, gently shake the suction filter bottle to ensure complete degassing. But be careful not to let the water be sucked back into the vacuum pump. 546
C1 Reagents and materials
GB/T 15454—95
Appendix C
Simultaneous determination of sodium, ammonium, potassium, magnesium and calcium ions (for use in units equipped with separation columns for simultaneous determination of Na+, NH+, K+, Mg2+ and Ca+) (reference)
C1.1 Standard stock solutions for ion chromatography Pipette 4.00 mL of sodium ion standard stock solution (5.1.1), 10.00 mL of ammonium ion standard stock solution (5.1.2), 10.00 mL of potassium ion standard stock solution (5.1.3), 5.00 mL of magnesium ion standard stock solution (5.2.1) and 10.00 mL of calcium ion standard stock solution (5.2.2) into a 100 mL volumetric flask, dilute to the mark with water and shake well. Store in a polyethylene bottle and place in a refrigerator (4°C). C1.2 Standard working solution for ion chromatography Pipette 10.00 mL of the standard stock solution for ion chromatography (C1.1) into a 100 mL volumetric flask, dilute to the mark with water, and shake well. The concentrations of Na+, NHt, K+, Mg2+, and Ca2+ in this solution are 4.00 mg/L, 10.00 mg/L, 10.00 mg/L, 5.00 mg/L, and 10.00 mg/L, respectively.
C1.3 Eluent, regeneration solution
Prepare according to the instructions for use of the separation column and suppression column. C2 Instruments and equipment
General laboratory instruments and
C2.1 Ion chromatograph (RSD<3%);
C2.2 Syringe: minimum capacity 1mL;
C2.3 Recorder: response time <2s, (or integrator, microcomputer); C2.4 High-efficiency cation separation column, suppression column and guard column for the one-time determination of Na+, NH+, K+, Mg2+ and Ca2+. C3 Selection of chromatographic conditions
According to the optimal conditions provided in the instrument and chromatographic column manual, adjust the eluent flow rate, conductivity detector output range, recorder paper feed speed and signal size millivolt range, and inject samples only after the baseline is stable. C4 Preparation of sample solution
Same as Chapter 8 of this standard.
C5 Simultaneous determination of sodium, ammonium, potassium, magnesium and calcium ions Turn on the machine, balance the separation column (C2.4) with the eluent (C1.3), wait for the baseline to stabilize, start to introduce the standard working solution (C1.2) to obtain the standard spectrum; then introduce the water sample (C4) to obtain the spectrum. If necessary, rinse the separation column and turn off the machine. C6 Expression of analysis results
Same as Chapter 10 of this standard.
Additional instructions:
GB/15454—95
This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Tianjin Chemical Research Institute of the Ministry of Chemical Industry. This standard was drafted by the Tianjin Chemical Research Institute of the Ministry of Chemical Industry and the Beijing Institute of Mineral Geology. The main drafters of this standard are Shao Weiren, Jiang Renyi, Zhang Yanli, Wang Kejuan and Zhu Chuanjun. This standard adopts the "Method 300.7 - Chemical Suppression Ion Chromatography for Determination of Sodium, Ammonium, Potassium, Magnesium and Calcium Dissolved in Precipitation" of the Development and Research Center and Environmental Monitoring Laboratory of the United States Environmental Protection Agency.
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.