Glucosin oxidase method to measure blood sugar concentration.

the "Experimental Principles

(i) color analysis method

color analysis method is to compare the color of the colored substance solution color, to determine the concentration of the substance method. Some of the substance solutions tested had colors themselves, while others, although not colored, could be added to the sample a suitablereagents to produce a coloredcompound The depth of the solution color is directly related to the content of the chemical component in the sample. With the help of photoelectromeometers and hydrometometers, the unknown content of the colored solution and the known content of the colored solution can be compared, and the content of the unknown solution can be calculated.

based on Lambert's law and Beer's law, the calculation formula of color analysis is derived from this second law.

Lambert's Law: When a monochrome ray passes through a colored solution, the intensity of the light decreases because the solution absorbs a portion of the light. When the solution concentration (C) remains the same, the thicker the layer of liquid through which light passes, the greater the decrease in light.

₀ the intensity of light before it passes through the solution (incoming light intensity);

I - the intensity of light passing through the solution (through light intensity);

L

and I/I₀ indicate the degree to which light passes through the solution, called light transmission, T indicates. The T is I/I ₀.

Lambert's law proves that - lgI/I₀∝L, i.e. -lgT∝L

is written as an equivalent - lgI/I₀ K ₁1 L/gt;

-lgI/I₀ s lgI₀/I, so the upper version can be written lgI/I₀. The KL

lg I₀/I as absorbent (A), or E), or light Density ( OD or D), so

AK₁L/... (1)

is known by (1) type, when the concentration of the solution remains the same, the absorbance of the solution (A) is directly related to the thickness of the solution layer, which is Lambert's law.

K₁ in the upper model is constant, and its value is related to the wavelength of the incoming light, the concentration and properties of the solution.

Beer's Law: After a monochrome light passes through a colored solution, if the thickness of the solution remains the same, the intensity of the light through it is related to the concentration (C) of the solution, the greater the concentration of the solution, the weaker the intensity of the light, and their relationship is:

-lgI/I ₀∝C, -lgI/I₀ - lgT - lgI₀/I

A∝C, written as an

. A K ₂C/ C...... (2)

K₂ is also a constant, and its value varies with the wavelength of the incident light and the nature of the solution.

to merge the above (1) (2) two,

A-KCL...... (3)

this is Lambert-Beer's law, that is, the absorbance of the solution is directly related to the concentration of the solution and the product of the thickness of the liquid layer.

color analysis, two solutions of the same nature and different concentrations were measured under the same conditions, one for a standard solution with a known concentration and one for a solution with an unknown concentration.

: C₁ is the concentration of the standard solution,

C₂ is the concentration of the unknown solution,

A₁ is the concentration of the standard liquid measured,

A₂ is the concentration of the measured unknown solution.

press (3), then

A₁ KC₁L /; A₂KC₂L/

Transfer A₁/C₁KL₁A/gt ₂/C₂KL₂

In the use of photoelectrometers or hydrometry timing, the solution is placed in a fixed color cup for color, so L₁

A₁/C_{1 2} / C ₂

moved items to

C₂ a ₁ / A₂×C₁... (4)

(4) formula is an important formula commonly used in color analysis, as long as the dilution of the sample is multiplied by the multiplier, the content of the substance can be calculated. It should be kept in mind that it should be used frequently in future experiments.

(ii) 721-type ionometer

1. Before use, check that the components of the instrument are normal and that the knobs should be located at the starting position.

2. Check that the supply voltage is in line with the instrument requirements.

3. Power on, turn on the dark box of the color slot, adjust the 0-button button, so that the meter pointer is located at T at 0, warm up 10min.

4. Turn the wavelength selection button and select the appropriate wavelength. Use the sensitive selection button to select the corresponding amplification sensitivity (sensitive selection button first adjust 1 gear, if not 0, then gradually increase the high-grade).

5. Take 3 color cups, loaded with blank liquid, standard liquid and measurement liquid, and put the color tank in turn.

6. Cover the color slot, place the blank tube on the optical path, adjust the 100-button button, and point the pointer to 100 light transmission.

7. Open the color cover, return the pointer to 0, and then cover the color slot cover to see if the pointer is to 100. If adjusted, the 0-button button and the 100-button button can no longer be turned at will.

8. Pull the color cup lever, in turn, the standard liquid and the measuring liquid aimed at the light path, respectively, read out the absorbance degree.

9. After use, return the 0 and 100 buttons to the starting position and cut off the power supply. <