Flame photometric analysis, is a kind of emission spectrometry, the solution to be measured by compressed air atomization in the combustible gas mixture after combustion into a flame, by the flame excitation, the elements can be emitted by the unique spectrum, due to the low excitation energy of the flame, so the elements are excited only in the alkali metals and alkaline earth metals. The spectrum of potassium is dark red, its wavelength is 765nm, the spectrum of Na is yellow, its wavelength is 589nm. the greater the concentration of the metal element in the solution, the stronger the emitted spectra, so in a certain excitation conditions, such as combustible gases and compressed air pressure and the flow rate of specimen liquid and other factors to maintain consistency, the concentration of the solution and the flame photometer to detect the flow of the meter's pointer readings are proportional to the known concentration of standard solution by comparing with their own. The concentration of potassium or sodium in the specimen can be found by comparing with the standard solution of known concentration. This experiment is derived from the laboratory instruction of 5-year undergraduate testing program of Mudanjiang Medical College.
Operation method
Direct method of serum potassium-sodium flame photometric analysis experiment
Principle
Flame photometric analysis, is a kind of emission spectrometry, the solution to be measured by compressed air atomization in the combustible gas mixture after combustion into a flame, by the flame excitation, the elements can be emitted by the unique spectrum, due to the low excitation energy of the flame, so the elements are excited only in the alkali metals and alkaline earth metals. The spectrum of potassium is dark red, its wavelength is 765nm, the spectrum of Na is yellow, its wavelength is 589nm. the greater the concentration of the metal element in the solution, the stronger the emitted spectra, so in a certain excitation conditions, such as combustible gases and compressed air pressure and the flow rate of specimen liquid and other factors to maintain consistency, the concentration of the solution and the flame photometer to detect the flow of the meter's pointer readings are proportional to the known concentration of standard solution by comparing with their own. The concentration of potassium or sodium in the specimen can be found by comparing it with a standard solution of known concentration.
Materials and Instruments
HG-Ⅲ Flame Photometer HG-5 Flame Photometer Move I. Experimental apparatus: HG-Ⅲ type flame photometer or HG-5 type flame photometer Caveat 1. the flame must be adjusted to the best state, the instrument should be preheated and stabilized before testing, otherwise it will affect the stability and repeatability of the readings. 2. pay attention to fire prevention when using the instrument, and shutdown steps to be clear, the correct shutdown method is to turn off the air compressor, so that the gas flame naturally extinguished, and then cut off the voltage, and then turn off the ignition of the needle valve and the sample switch. 3. Flame photometric measurement of potassium. Sodium linear range of about 20ppm, with the increase in concentration will produce self-absorption phenomenon (autocorrosion) and affect the accuracy of the results, so the sample should be diluted, clinically the serum is diluted 100 times, and also for the determination of potassium and sodium. Therefore, the sample should be diluted, and the serum should be diluted 100 times for both potassium and sodium determination. 4. The instrument should be kept at room temperature, no bright light, no vibration, no dust environment, because the flame by air pressure. Flow rate. Fuel. The flame is greatly affected by air pressure, flow rate, fuel and temperature. 5. When using gas or liquefied petroleum gas, the power supply should be turned off first, and then turn off the other switches. 6. Blood samples should not be hemolyzed. For more product details, please visit Aladdin Scientific website.
Host part: optical control system, spray combustion chamber, electronic detection system, optical and measurement system is divided into two sets of potassium and sodium, should be measured at the same time the results of both, supporting parts including air compressor, water filter, gas stabilizer, gasoline vaporization cylinder, can use gas, fossil oil and gasoline and other fuels.
Second, the experimental reagents:
1. potassium standard storage solution (10mol / L); take a few grams of sodium chloride (GR or AR), placed in a weighing bottle, dried in the oven at 120 ℃ until recovery, removed and placed in a glass desiccator cooled to room temperature, weighing 0.7456 grams, with a bath of deionized water to dissolve the 1000ml volumetric flask, and then diluted with deionized water to the scale, stored in a plastic bottle, placed in the refrigerator.
2. Sodium standard storage solution (l00mmol/L) Take several grams of sodium chloride (GR or AR), dry in 110-120 ℃ oven, take out and put it in a glass desiccator to cool at room temperature, accurately weigh 5.845g, dissolve in deionized water, transfer it into a 1000ml volumetric flask, dilute it to the scale with deionized water, mix it well, and then store it in plastic bottles for spare.
3. Mixed specimen application solution (potassium 0.04mmol/L; sodium 1.4mmol/L) accurately absorb the potassium standard solution of 4ml, sodium standard solution of 14ml, placed in 100ml volumetric flasks, diluted with deionized water to the scale, warmed, stored in plastic bottles for spare.
Third, the experimental operation;
l. Dilution of serum: take 0.1ml of serum and put it in a large test tube, add 9.9ml of deionized water, mix well, for potassium. For potassium and sodium determination.
2. Instrument preparation:
① Connect the optical circuit, start the air compressor and turn on the power.
② Turn on the ignition and adjust the flame to the best condition.
③ Instrument preheating, preheating time about twenty minutes or so.
④ Instrument calibration, adjust zero and fullness.
3. Serum sample determination:
Potassium and sodium can be measured at the same time. Repeat the zero adjustment with deionized water and the fullness adjustment with mixed standard solution several times. If there is no drift in the needle of both potassium and sodium flowmeters, the diluted serum sample can be placed at the lower end of the injection tube to start the injection. Take a reading and rinse the tube with deionized water before proceeding with the determination of a single serum sample. When testing multiple samples consecutively, a standard solution correction should be performed between every 3-5 samples, and the samples can be rinsed with deionized water for zeroing in order to eliminate sample interferences, and then the tubing can be rinsed with deionized water and the unit can be turned off after the measurement is completed.
IV. Calculation:
(potassium sample reading/potassium standard solution reading) × 4 = serum potassium mmol/L
(Sodium sample reading/sodium standard solution reading)×140=serum sodium mmol/L
Reference value: Serum sodium: 136-145 mmol/L
Serum potassium: 3.5-5.3 mmol/L