Hydride generator concise determination method Preparation and determination of simple methods for the determination of trace amounts of As, Se, Sb, Bi, Pb, Sn, Te, Ge and Hg by hydride atomic absorption spectrometry Develop the working order of the analytical method 1. First prepare a standard solution with a content of about 50-100 times sensitivity (the best absorbance 0.2-0.5Abs) and a blank solution to check or determine: a. Chemical conditions that occur 2. Prepare a series of standard solutions, taking arsenic as an example: with 0, 2, 4, 6, 8, ng/ml, draw a standard curve. The range of standard solution solutions: up to about 100-150 times the sensitivity, must have a blank solution. 3. Preparation of potassium borohydride. Potassium borohydride KBH4 (or sodium), most of the hydride elements used 1.5%. 1.5 g of potassium borohydride and 0.3 g of sodium hydroxide (stabilizer) were weighed into a plastic bottle (not available in a glass vessel), and dissolved in 100 ml of distilled water. One week at room temperature. Determination of mercury with 0.5% potassium borohydride, 0.1% sodium hydroxide. 4. Preparation of carrier liquid: 1% (v/v) hydrochloric acid. 5. Pretreatment of the sample: a. Dissolve the sample according to the relevant method. 6. Check for the presence of interfering elements in the sample: 7. Interference control 8. Determine the standard sample and verify the correctness of the method used. Note: If you have any difficulty in finding reference materials, please contact us to find it, and you can take the internship operation and standard liquid measurement in our company, and take care of yourself. Available measurement conditions . Common conditions for each element 2. Generator use conditions: see the instruction manual note: . Unique conditions for each element Arsenic As Selenium Se Lead Pb Tin Sn 铋Bi 碲Te 锑Sb Mercury Hg (1). Wavelength: 253.7 nm. Note: Note: The atomic absorption models are different, the performance is different, and the sensitivity is also different. Therefore, when making series standards, the standard series should be configured according to the specific conditions. In short, the maximum reading should not exceed 0.8A. Otherwise, the concentration will be too high and the curve will be bent. The reading should be greater than 0.02A (the reading after subtracting the blank) 8. Potassium borohydride configuration: Weigh 3g of potassium borohydride into a plastic bottle, add 0.6g of sodium hydroxide, and add distilled water to dissolve it to 200mL. (Save for 1 week) Lead test Note: The atomic absorption models are different, the performance is different, and the sensitivity is also different. Therefore, when making series standards, the standard series should be configured according to the specific conditions. In short, the maximum reading should not exceed 0.8A. Otherwise, the concentration will be too high and the curve will be bent. The reading should be greater than 0.02A (the reading after subtracting the blank). 7. The blank is configured and the remaining 0.5% hydrochloric acid lead solution is used. Mercury testing Selenium test 1. Prepare a clean 100mL volumetric flask of 6 or more, 500mL volumetric flasks, 200mL plastic bottles, 2mL and 5mL, 10mL pipettes, beakers, electric stoves. note: The method we give you can't be said to be the best, but the hydride element standard can be made according to the above method. You can further explore better methods of measurement when you have time and conditions, and we can help you. You can help you with publications in professional journals (including financial sponsorship). National standard method for hydride atomic absorption Cold atomic absorption spectrometry CJ/T 68-1999 Determination of mercury in municipal wastewater - Cold atomic absorption spectrophotometric method Hydride element national standard method GB/T 16415-1996 Determination of selenium in coal - Hydride atomic absorption Chinese Pharmacopoeia 2008, Appendix IX Determination of lead, cadmium, arsenic, mercury, copper "Water and Wastewater Analysis and Analysis Methods" Fourth Edition, Chapter IV Determination of Metals and Their Compounds Contact: Exhibition Rfid Card Cost,Rfid Ticket Card,Rfid Paper Cards,Printed Rfid Cards Guangdong Xinye RFID Label Application Co., Ltd , https://www.xinyerfid.com
b. Generator conditions
c. Host conditions
d. Stability of readings
e. Actual sensitivity achieved (minus blank reading calculation).
b. Whether a pre-reduction of the measured element is required.
c. Dilute to a certain multiple so that the reading does not exceed the maximum measurable concentration (corrected after actual measurement) and meet the requirements of chemical conditions.
a. Obtain the interference elements and interference quantities of the measured elements from the literature, and compare with the known coexisting elements of the test samples to determine whether interference needs to be controlled.
b. Check the presence or absence of interference with the recovery test: take 2 sample solutions, add one part of the measured element with a known amount, and add one part without adding. The content is measured and subtracted, and the recovery rate is calculated. The recovery rate is considered to be interference-free at 100 ± 2%. When 100±5%, if there is a higher requirement, it is considered to have interference and needs to be controlled.
a. Controlled by the methods provided in the literature and verified by recycling experiments.
b. For unclear interference, or interference that cannot be completely eliminated, and the recovery rate of different addition amounts are similar, that is, there is “multiplication interferenceâ€, multiplying a coefficient to get the correct value, and “standard addition method†can be used. Determination. When there is "additional interference", it cannot be eliminated by the standard addition method.
Host condition
a. Light source: Common hollow cathode lamps can be used. It is recommended to use high-performance hollow cathode lamps with high emission intensity and high sensitivity. Large passband width (up to 1-2nm, further increase strength) can be used. It can be powered by the host. Both lamps are used at the factory supplied operating current. (The company supplies high performance and ordinary hollow cathode lamps).
b. Measure the wavelength with the sensitive line of the measured element.
c. Reading method: Refer to the instruction manual of the generator and the host. It is recommended to use the peak height reading.
3. Carrier gas: pure nitrogen or pure argon. See “Effective Conditions for Each Element†for the flow rate.
1. There is a vent pipe on the rear panel of WHG-102A2. This tube can significantly increase the sensitivity of As. Se. Pb. Sn. Te. When measuring other elements, it should be closed (plugged or clamped), open or close. It is indicated in the “Special Conditions for Each Elementâ€.
2. The concentration of the standard solution used in the condition test is large, and the absorbance is also large. It may have reached the bending curve of the working curve. The “sensitivity†value calculated by this data is too large (the sensitivity is low). Sensitivity should be calculated using data from a lower concentration standard (absorbance of approximately 0.1-0.2).
(1). Wavelength: 193.7 nm.
(2). Carrier gas (nitrogen or argon) flow rate: 150-180 ml/min.
(3). Arsenic (V valence) should be reduced to arsenic (III valence): add potassium iodide to the concentration of 0.5-1% (V/V) before adding the sample or standard solution to be determined, and add ascorbic acid to the concentration of 0.2- After 0.5% constant volume, it is heated in a boiling water bath and the temperature is raised to about 80-90 ° C). After cooling, it can be measured.
(4). Acidity of sample and standard solution: The volume is adjusted with 10% hydrochloric acid (V/V,), and the acidity in the literature is 1-9M.
(5). Ventilation tube after generator: Open.
(1). Linear range 1-10ng/mL (also in the range of 1-20ng/mL)
(2). Sensitivity: Factory default 0.18 ng/mL/1% A. (Optimized to 0.08 ng/ml1%A), this sensitivity is measured by high-performance lamps and is related to the performance of the atomic absorption host. The sensitivity of the host is also different, and all subsequent sensitivity indicators are the same.
(1). Wavelength: 196.0 nm.
(2). Carrier gas flow rate: 150-180mL/min.
(3). Selenium (VI price) reduced to selenium (IV price): If the selenium in the standard solution is tetravalent, it may not be pre-reduced, and the hexavalent should be reduced. After the sample or standard is dissolved, add a few milliliters of hydrochloric acid (1:1), and use a common glass device to boil the solution. With polyethylene or polytetrafluoroethylene (PTFE) open-mouth flask, there was no loss when boiling. Allow to cool off after heating for a few minutes.
(4). Acidity: 20% (V/V) hydrochloric acid medium for sample and standard solution. The literature has an acidity of 2.5-5M.
(5). Linear range 10-80ng/mL
(6). Ventilation tube after generator: Open.
(7). Sensitivity: 0.32 ng/mL/1%.
(1). Wavelength: 217.0 nm for high performance lamps and 283.3 nm for normal lamps.
(2). Carrier gas flow rate: 150 ml/min.
(3). Acidity: 0.5% (V/V) hydrochloric acid medium is used for both the sample and the standard solution. The literature has an acidity of 0.1-0.2M.
(4). Oxidizer: Lead ion is usually 2 valence, lead in hydride is 4 valence, and oxidant should be added to the solution.
a. Use potassium ferricyanide oxidant (only for samples with low heavy metal content such as biological materials), the highest sensitivity. Add before constant volume, and make up to volume after dissolution. The concentration was 0.4% (0.8-1.0% in the literature).
b. The use of hydrogen peroxide, ammonium persulfate, potassium dichromate and other oxidants in the literature is less sensitive than potassium ferricyanide, but less interfering elements (see literature).
(5). Generator (rear) vent: Open.
(6). Linear range 1-10ng/mL
(7). Sensitivity: 0.18 ng / mL / 1%. (Optimized with potassium ferrocyanide oxidizing agent can reach 0. 08ng / mL / 1%).
(1). Wavelength: 286.3nm for ordinary lamps and 224.6 nm for high-performance lamps.
(2). Carrier gas flow rate: 300 mL/min.
(3). Acidity: 0.5% HCl (V/V) The acidity of the literature is 0.1-0.2M.
(4). Ventilation tube after generator: Open.
(5). Linear range 10-80ng/mL
(6) Sensitivity: 0.42 ng/mL/1% A.
(1). Wavelength: 223.0 nm.
(2). Carrier gas flow rate: 100 mL/min.
(3). Acidity: 20% (V/V) hydrochloric acid. Literature acidity 1-9M
(4). Ventilation tube after generator: Off.
(5). Linear range 10-80ng/mL
(6). Sensitivity: 0.42 ng/mL/1% A.
(1). Wavelength: 214.3 nm.
(2). Carrier gas flow rate: 150 ml/min.
(3). Reduce 碲(VI) to 碲(IV): Add concentrated hydrochloric acid to the sample or standard solution and boil for 1 minute (no loss).
(4). Acidity: 20% (V/V) hydrochloric acid medium. The literature acidity is 2.5-3.6M.
(5). Ventilation tube after generator: Open.
(6). Linear range 10-80ng/mL
(7). Sensitivity: 0.4 ng/ml/1% A.
(1). Wavelength: 217.6 nm.
(2). Carrier gas flow rate: 80-100ml/min.
(3). Reduction of 锑(V) to 锑(III) 锑(V) is about 2 times lower than 锑(III). The reduction method is the same as arsenic, but it can be completed instantaneously at normal temperature without heating.
(4). Acidity: 10% hydrochloric acid (V/V). The literature has an acidity of 1-9M.
(5). Generator (rear) vent: Close.
(6). Linear range 5-70ng/mL
(7). Sensitivity: 0.3 ng/ml/1% A.
(2). Carrier gas flow rate: 100ml/min.
(3) Potassium borohydride concentration: 0.5-1.5% (medium 0.1% HaOH).
(4). Acidity: 4% (V/V) sulfuric acid. The literature covers a wide range of acidity.
(5). Add appropriate amount of permanganate (micro-purple) to the sample.
(6). Ventilation tube after generator: Off.
(7). Linear range 10-80ng/mL
(8). Sensitivity: 0.5 ng/ml/1% A.
1. The electrothermal quartz absorber tube is not energized.
2. The ng-class mercury is far below the safe allowable amount, and it will not cause harmful pollution.
3. If a sample with a particularly high content (absorbance >1A) produces a memory effect in the pipeline, the carrier gas can be increased, the waste liquid pipe can be clamped, and the ventilation can be ventilated until the blank reading is normal (about several minutes to more than one hour); It is also possible to remove the transition tube between the generator and the electrothermal quartz tube and blow it to both sides with compressed air until the blank reading is normal.
Arsenic test
1. Prepare a clean 100mL volumetric flask of 6 or more, 500mL volumetric flasks, 200mL plastic bottles, 2mL and 5mL, 10mL pipettes, beakers, electric stoves.
2. Prepare hydrochloric acid, potassium borohydride, sodium hydroxide, distilled water or deionized water.
3. Prepare arsenic standard solution, potassium iodide, ascorbic acid.
4. Valence reduction: Put 1mL of 100μg/mL As standard solution into a 100mL volumetric flask, add 0.8g of potassium iodide, dissolve to 100mL with 10% hydrochloric acid solution, pour into a beaker, and heat it on the electric furnace. Microboil, let cool, add 0.5g ascorbic acid. This standard concentration (content) was 1 μg/mL of AsIII mother liquor. Place it in a brown bottle and keep it sealed from light for half a year. No need to do valence reduction when using it again.
5. 1% carrier liquid configuration: using a 500 mL volumetric flask, add 5 mL of hydrochloric acid, and dilute to 500 mL with distilled water.
6. Blank configuration: use a 500 mL volumetric flask, add 50 mL of hydrochloric acid, and dilute to 500 mL with distilled water. This is 10% hydrochloric acid.
7. Argon standard series configuration: Prepare four 100mL volumetric flasks, add 0.2mL, 0.4mL, 0.6mL, 0.8mL standard mother liquor, and dissolve to 100mL with 10% hydrochloric acid. This is a series of standard solutions of 2, 4, 6, and 8 ng/mL, respectively.
9. The blank is configured with the remaining 10% hydrochloric acid solution.
10. The valence treatment and dilution configuration of the sample, adjust the acidity of the dissolved sample to 10% hydrochloric acid, add 0.8% potassium iodide, pour into a beaker, place on an electric furnace and heat to a slight boiling, and add 0.5% ascorbic acid. This is the sample mother liquor and needs to be diluted to within the curve when measured.
11. Sample blank: The sample blank is the same as the standard blank.
1. Prepare more than 6 clean 100mL volumetric flasks; 2 500mL volumetric flasks; 2 200mL plastic bottles; 2mL, 5mL, 10mL pipettes; beakers; electric furnaces;
2. Prepare hydrochloric acid, potassium borohydride, sodium hydroxide, distilled water or deionized water, prepare lead liquid, iron potassium hydride.
3. Place 1 mL of 100 μg/mL Pb standard solution in a 100 mL volumetric flask and dissolve to 100 mL with a 0.5% hydrochloric acid solution. This standard concentration (content) was 1 μg/mL/Pb of mother liquor. Place it in a brown bottle and keep it sealed from light for half a year.
4. 1% carrier liquid configuration: using a 500 mL volumetric flask, add 5 mL of hydrochloric acid, and dilute to 500 mL with distilled water.
5. Blank configuration: use 500mL volumetric flask, add 2.5mL hydrochloric acid, add 4g iron hydride (oxidant, the color should be purple red, if it has turned yellow green or yellow blue, it has been deteriorated, can not be reused, shape As a solid), make up to 500 mL with distilled water, which is a lead blank solution of 0.5% hydrochloric acid.
6. Configuration of lead standard series: Prepare four 100mL volumetric flasks, add 0.25mL, 0.5mL, 0.75mL, 1.0mL of 1μg/mL lead standard mother liquor, and use the 0.5% hydrochloric acid lead blank solution. Set to 100 mL. This is a series of standard solutions of 2.5, 5, 7.5, and 10 ng/mL. This standard solution can be used for no more than 3 days.
8. Potassium borohydride configuration: Weigh 3g of potassium borohydride into a plastic bottle, add 0.6g of sodium hydroxide, and add distilled water to dissolve it to 200mL. (Save for 1 week)
9. In the sample dilution configuration, adjust the acidity of the dissolved sample to 0.5% hydrochloric acid solution, add 0.8% potassium ferricyanide, and dilute to the standard curve when measuring.
10. Sample blank: The sample blank is the same as the standard blank.
1. Prepare 6 clean 100mL volumetric flasks, 2 500mL volumetric flasks, 2 200mL plastic bottles, 2mL and 5mL, 10mL pipettes.
2. Prepare sulfuric acid, hydrochloric acid, potassium borohydride, sodium hydroxide, potassium permanganate, distilled water or deionized water.
3. 1% carrier liquid configuration: use a 500mL volumetric flask, add 5mL hydrochloric acid, and dilute to 500mL.
4. Blank configuration: use 500mL volumetric flask, add 20mL sulfuric acid, dilute to 500mL, add appropriate amount of potassium permanganate, which is based on color micro-purple, which is 4% sulfuric acid solution.
5. Configure 1μg/mL/Hg mother liquor: 1μg/mL standard solution Hg mother liquor is prepared according to the content of the standard solution.
6. Configuration of the standard series: Prepare four 100mL volumetric flasks, add 1mL, 2mL, 3mL, 4mL of Hg standard mother liquor, and dissolve to 100mL with 4% sulfuric acid. This is a series of standard solutions of 10, 20, 30, 40 ng / mL, respectively. Note: The atomic absorption models are different, the performance is different, and the sensitivity is also different. Therefore, when making series standards, the standard series should be configured according to the specific conditions. In short, the maximum reading should not exceed 0.8A. Otherwise, the concentration will be too high and the curve will be bent. The reading should be greater than 0.02A (the reading after subtracting the blank)
7. The blank is configured with the remaining 4% sulfuric acid solution.
8. Configuration of potassium borohydride: Weigh 2 g of potassium borohydride into a plastic bottle, add 0.2 g of sodium hydroxide, and add distilled water to dissolve to 200 mL. (Save for 1 week)
9. Dilution configuration of the sample: adjust the acidity to 4% sulfuric acid with the dissolved sample. Dilute to a linear range.
10. Sample blank: The sample blank is the same as the standard blank.
2. Prepare hydrochloric acid, potassium borohydride, sodium hydroxide, distilled water or deionized water.
3. 1% carrier liquid configuration: use a 500mL volumetric flask, add 5mL hydrochloric acid, and dilute to 500mL.
4. Blank configuration: use a 500mL volumetric flask, add 100mL hydrochloric acid, and dilute to 500mL, this is 20% hydrochloric acid.
5. Valence reduction: 10mL 100μg/mL Se standard solution and 10mL concentrated hydrochloric acid are placed in a beaker and placed on an electric furnace to heat to a slight boiling. (Note: there is a loss of using ordinary glass instruments to boil the solution.) Ethylene or polytetrafluoroethylene (PTFE) open-mouth flask, no loss when boiled). After cooling, the concentration (content) of the standard solution was 50 μg/mL.
6. Configure 1μg/mL/Se mother liquor: Take 2mL of the reduced standard solution into a 100mL volumetric flask, add the prepared 20% hydrochloric acid solution and dissolve to 100mL, which is 1μg/mL of the standard solution mother liquor.
7. Configuration of the standard series: Prepare four 100mL volumetric flasks, add 1mL, 2mL, 3mL, 4mL Se standard mother liquor, and dissolve to 100mL with the configured 20% hydrochloric acid. This is a series of standard solutions of 10, 20, 30, 40 ng / mL, respectively. Note: The atomic absorption models are different, the performance is different, and the sensitivity is also different. Therefore, when making series standards, the standard series should be configured according to the specific conditions. In short, the maximum reading should not exceed 0.8A. Otherwise, the concentration will be too high and the curve will be bent. The reading should be greater than 0.02A (the reading after subtracting the blank)
8. The blank is configured with the remaining 20% ​​hydrochloric acid solution.
9. Configuration of potassium borohydride: Weigh 3 g of potassium borohydride into a plastic bottle, add 0.6 g of sodium hydroxide, and add distilled water to dissolve to 200 mL. (Save for 1 week)
10. Valence treatment and dilution configuration of the sample: 10 mL of the dissolved sample is added with 10 mL of concentrated hydrochloric acid, and heated to a slight boiling, which is the sample mother liquor.
11. Sample blank: The sample blank is the same as the standard blank.
(1). Samples containing hydrofluoric acid should not be used (inhaled). If necessary, please contact the manufacturer to replace the generator of other models.
(2). Because the generator is used to determine trace elements by hydride atomic absorption method, because it is low or trace, special attention should be paid to the accuracy of pipetting and final volume determination. Even small error errors will give measurement data. It has a great impact, so in the preparation process of samples and standards, all the utensils must be carefully cleaned in strict accordance with the relevant operating procedures, and the preparation process is carefully and carefully. Please contact us if you have any problems during use.
DZ/T 0064.26-1993 Groundwater quality test method - Determination of mercury by cold atomic absorption spectrophotometry
GB 7468-1987 Determination of total mercury in water -- Cold atomic absorption spectrophotometric method
GB/T 8914-1988 Hygienic standard for mercury in the atmosphere of residential areas - Amalgam Mercury enrichment - Atomic absorption method
GB/T 16012-1995 Method for determination of mercury in air of workplace by cold atomic absorption spectrometry
Reduction gasification of mercury in the air of WS/T 128-99 workplace - Determination of atomic absorption spectrometry
CJ/T 98-1999 Determination of Mercury in Municipal Domestic Wastes - Cold Atomic Absorption Spectrophotometry
GB/T 15555.1-1995 Determination of total mercury in solid waste - Cold atomic absorption spectrophotometric method
WS/T 26-1996 Method for determination of mercury in urine by cold atomic absorption spectrometry
GB/T 8220.7-1998 é“‹ chemical analysis method ion exchange separation - hydride generation - flame atomic absorption spectrometry determination of arsenic
Hydride generation in the air of WS/T 129-99 workplace - Determination of arsenic absorption spectrometry
Hydride generation in the air of WS/T 130-99 workplace - Determination of atomic absorption spectrometry
GB/T 12687.3-1990 Determination of arsenic content by hydride flame atomic absorption spectrometry
Hydride generation-atomic absorption spectrometry for determination of selenium in serum of WS/T 109-99
WS/T 29-1996 Determination of arsenic in urine by flame atomic absorption spectrometry.
WS/T 47-1996 Determination of selenium in urine by hydride generation-atomic absorption spectrometry
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