CN104297422A - Tear-off band-shaped three-layer filter membrane strip for determining content of metals in air, and making method thereof - Google Patents

Abstract

The invention discloses a tearable strip-shaped three-layer filter membrane strip for measuring metal content in the air and a manufacturing method, belonging to the field of laboratory consumables. Including the support shaft, etc., the metal sprayed filter membrane is located between the filter membrane protection paper and the filter membrane protection paper, which is an extended belt structure. The two edges of the extension belt are glued into one body, and the whole body is pressed by the adhesive bonding method. One body; the filter membrane protector paper, the metal sprayed filter membrane, and the filter membrane protector paper are wound into rolls with the support shaft as the axis. The invention pressurizes and sprays the metal salt solution on the side close to the metal sprayed filter membrane and the filter membrane protective paper, adopts a fixed-point pressurized uniform mist spraying process, and pressurizes the spray at a fixed point under the metal sprayed filter membrane and the filter membrane protective paper. The paper is evenly fed under the shaped nozzle at the same speed. After spraying, it is quickly air-dried, covered with filter membrane protection paper, and then pressurized and pressed. Use a laser cutting machine to punch out breakpoint lines at equal intervals, and pack them in rolls. The process of the invention is simple, effective, low in cost, and has very broad prospects for popularization and application.

Description

Determination of metal content in the air with a tearable strip-shaped three-layer filter membrane strip and manufacturing method

technical field

The invention belongs to the field of laboratory consumables, and in particular relates to a tearable band-shaped quantitative metal three-layer filter membrane for measuring the metal content in the air and a manufacturing method thereof.

Background technique

At this stage, at present, the method of collecting metals in the ambient atmosphere is mainly to filter a certain volume of air samples, and trap the particulate and aerosol metals in the air in the microporous filter membrane. Atomic absorption spectrophotometry is often used for sample determination, which requires digestion of the filter membrane in the experimental pretreatment stage and transfer of metals to the solution for determination.

In the detection of metal content in the filter membrane, the commonly used quantitative method is the standard curve method. The method uses directly prepared metal solutions of different concentrations as each point of the standard curve to draw a standard curve, and uses the standard curve to measure the concentration of the sample. Subtract the sample blank, experimental blank or reagent blank from the experimental value as the test result. This method is used in the detection methods of the existing GBZ/T160.1-2004 to GBZ/T160.26-2004 and other standards. Due to the low concentration of the sample, the effects of reagent masking effect, container wall adsorption effect, microporous membrane material, reagent composition, digestion speed, solvent residue, environmental conditions, and atomic absorption spectrophotometer conditions cannot be ignored. The degree of positive or negative effect on the sample measurement after impact superposition is very different due to the metal type and digestion situation, which will affect the slope and intercept of the standard curve. The standard curve method can only deduct the deviation of the standard curve in terms of intercept to a certain extent, and cannot deal with the influence of the above influence on the slope of the standard curve, which has limitations, resulting in the inability to obtain correct measurement results during actual measurement.

Therefore, there is an urgent need for a novel technical solution in the prior art to solve this problem.

Contents of the invention

The technical problem to be solved by the present invention is to provide laboratory testing personnel with a quantitative metal substance used for preparing a standard curve when measuring the metal content in the air. The quantitative metal substance carrier referred to in the present invention is a tearable double-layer filter membrane strip.

Detachable band-shaped three-layer filter strip for measuring metal content in the air is characterized in that it includes a support shaft, a filter membrane protection paper, a metal sprayed filter membrane, and a filter membrane protection paper. The metal sprayed filter membrane is located at Between the filter membrane protective paper and the filter membrane protective paper, the three are extended strip structures, and the two edges of the three extended strips are bonded together by glue, or the three extended strips are made of viscose The integral crimping method is pressed into one; the extension belt that integrates the upper filter membrane protection paper, the metal sprayed filter membrane and the lower filter membrane protection paper is wound into a roll with the supporting shaft as the axis.

The material of the support shaft is plastic or paper, and the shape of the support shaft is a hollow or solid cylindrical structure.

Two circular protective sheets are fixedly installed on both sides of the cylindrical structure of the support shaft. The circular protective sheet is located under the metal sprayed filter membrane to support the metal sprayed filter membrane. The material of the circular protective sheet is plastic or paper .

The materials of the filter membrane protective paper, the filter membrane protective paper and the metal sprayed filter membrane are all microporous filter membranes, and the distances between the breakpoint lines of the three are equal, and the breakpoint positions on the breakpoint lines are the same .

A method for manufacturing a tearable strip-shaped three-layer filter strip for measuring metal content in air is characterized in that:

Step 1. Spray the metal sprayed filter membrane and the side under the filter membrane protective paper by fixed-point pressure of the spraying head and uniform spraying of the metal salt solution, and the metal sprayed filter membrane and the filter membrane protective paper are under, The paper is evenly fed at the same speed under the fixed-point pressurized mist nozzle of the spraying head;

Step 2. Air-dry the metal sprayed filter membrane and the filter membrane protective paper after the spraying process within 3s to 5s;

Step 3, covering the filter membrane protective paper on the air-dried metal sprayed filter membrane and pressing and pressing;

Step 4. Use a laser cutting machine to cut breakpoint lines at equal intervals on the pressed filter membrane protection paper, the metal sprayed filter membrane, and the filter membrane protection paper;

Step 5. Combine the filter membrane protective paper, the metal sprayed filter membrane, the filter membrane protective paper under the filter membrane protective paper, the metal sprayed filter membrane, and the lower filter membrane protective paper after breaking the breakpoint line. The integrated extension band is wound into a roll with the supporting shaft as the axis.

In the first step, the spraying head controls the spraying width by controlling the distance from the metal spraying filter membrane and the spraying liquid pressure of the spraying head.

In the first step, the spraying head controls the metal content in the unit area of the metal spraying filter membrane according to the speed of paper passing under the metal spraying filter membrane and the metal concentration in the sprayed metal salt solution.

In the first step, the spraying pressure of the spraying head is 0.5MPa-5.0MPa, the metal spraying width is greater than 1/4 of the total width of the metal spraying material, and less than 3/4 of the total width of the metal spraying material, and the paper feeding speed is 0.005m/ s～0.2m/s, the metal content in the metal salt solution concentration is 0.1g/L～10g/L, the metal salt solution spraying speed is 0.1L/h～10L/h, and the metal salt solution pH value is 5.5～8.5.

In step 4, the distance between breakpoint lines is 0.3 cm to 3 cm, and the line width of break point lines is less than or equal to 0.2 nm.

In the step five, the band width of the extended belt which combines the filter membrane protective paper, the metal sprayed filter membrane and the filter membrane protective paper into one is 1cm-10cm.

Through the above-mentioned design scheme, the present invention can bring the following beneficial effects: the two edges or the whole of the upper and lower filter membrane protection papers of the present invention and the metal sprayed filter membrane are connected in a strip shape, and the adhesive crimping process is used as a whole to prevent the three between them. shift.

As shown in Fig. 1 and Fig. 2, for metal manganese and metal cadmium, the slope and intercept of the calibration curve prepared by standard solution and quantitative metal filter membrane digestion of the present invention are very different. Measure filter membrane lead, cadmium, manganese, zinc standard substance (cadmium 16.8 ± 1.0 μ g/ sheet, manganese 69.3 ± 1.0 μ g/ sheet) according to 4 standard curves shown in Table 1 and Fig. 1, Fig. 2, adopt quantitative method of the present invention The concentration of the filter membrane standard sample measured by the standard curve prepared by the metal filter membrane is closer to the true value. The experimental results showed that the slope of the standard curve and the recovery rate of samples showed opposite trends for cadmium and manganese, and the distortion was greater when the undigested standard curve was directly used for determination. When measuring different metal elements, using the quantitative metal filter membrane of the present invention to draw a standard curve after digestion can well eliminate the effects of drug masking, container wall adsorption, filter membrane material, pretreatment methods, environmental conditions, etc. Positive or negative effects, better experimental results are obtained.

Table 1

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and specific embodiment:

Fig. 1 is the manganese standard curve chart comparing prior art and the present invention.

Fig. 2 is the cadmium standard curve diagram comparing the prior art and the present invention.

Fig. 3 is a structural schematic diagram of a tearable strip-shaped three-layer membrane strip for measuring metal content in air according to the present invention.

Curve 1 in Fig. 1 is the standard curve prepared directly with manganese standard solution.

Curve 2 in Figure 1 is a standard curve configured with manganese quantitative filter strips.

Curve 1 in Fig. 2 is the standard curve prepared directly with cadmium standard solution.

Curve 2 in Figure 2 is a standard curve configured with cadmium quantitative filter strips.

Among Fig. 3 1-support shaft, 2-on the filter membrane protective paper, 3-breakpoint line, 4-metal sprayed filter membrane, 5-under the filter membrane protective paper.

Detailed ways

As shown in Figure 3, the metal content in the air of the present invention is measured with a tearable band-shaped quantitative metal double-layer filter strip consisting of a support shaft 1, a filter membrane protection paper 2, a metal sprayed filter membrane 4, a filter membrane 5 compositions under the protective paper.

The main body of the supporting shaft is made of plastic or paper material, and has a hollow or solid cylindrical structure. Two circular protective sheets are fixed on both sides of the cylindrical structure, made of plastic or paper, to provide support and protection for the filter membrane.

The upper and lower filter membranes are made of the same material as the metal sprayed filter membrane, both of which are microporous membranes, with equally spaced breakpoints and the same breakpoint position. The two edges of the upper and lower filter membrane protection paper and the metal sprayed filter membrane are connected in a strip shape or the whole adopts the adhesive crimping process to prevent the displacement between the three.

1 main process

The main process of the invention is to pressurize and spray the metal salt solution on the side close to the metal sprayed filter membrane and the filter membrane protective paper, adopt the fixed-point pressurized uniform spraying process, and the metal sprayed filter membrane and the filter membrane protective paper under the fixed point The paper is evenly fed under the pressurized mist nozzle at the same speed. After spraying, it is quickly air-dried, covered with filter membrane protection paper, and then pressurized and pressed. Use a laser cutting machine to cut out equal interval breakpoint lines and pack them into rolls.

The spraying width is controlled by controlling the pressure of the spraying liquid and the height of the spraying head from the filter membrane, and the metal content in the filter membrane per unit area is controlled by the speed of the paper and the metal concentration in the solution.

2 Specifications and parameters

Filter membrane protection paper and metal spraying filter membrane breakpoint line spacing 0.3cm-3cm, bandwidth 1cm-10cm, breakpoint line width less than or equal to 0.2nm, spraying pressure 0.5-5.0MPa, metal spraying width greater than the total width of metal spraying materials 1/4 is less than 3/4 of the total width of the metal spraying material, the paper feeding speed is 0.005-0.2m/s, the concentration of the spraying solution is 0.1-10g/L in terms of metal, the solution spraying speed is 0.1-10L/h, and the pH value of the solution is 5.5- 8.5.

3 control methods

pass

Example 1 Zinc three-layer filter membrane strip, solution; zinc chloride solution, distance between breakpoints 0.5cm, width 2cm, metal spraying width 1cm, spraying pressure 1.0MPa, paper speed 0.01m/s, concentration of spraying solution is expressed as zinc element The meter is 2g/L, and the solution spraying speed is 3.6L/h. Each 0.5cm wide three-layer filter strip contains 1 μg of sodium. The zinc content values of 20 filter membrane strips are determined in the following table by using the zinc filter membrane standard substance to prepare a standard curve:

Table 2

1 1.002μg 2 1.008μg 3 0.954μg 4 0.999μg 5 1.021μg 6 0.994μg 7 1.015μg 8 1.029μg 9 1.007μg 10 1.005μg 11 0.970μg 12 1.002μg 13 1.014μg 14 0.981μg 15 1.013μg 16 0.996μg 17 0.990μg 18 1.001μg 19 1.002μg 20 1.019μg

The arithmetic mean was 1.001, the standard deviation was 0.018, and there was no significant difference with the u test.

Example 2 Copper three-layer filter membrane strip, solution; copper sulfate solution, distance between breakpoints 1.0cm, width 4cm, width of metal pattern 2cm, spraying pressure 1.5MPa, paper speed 0.01m/s, concentration of spraying solution is measured as copper element The meter is 1g/L, and the solution spraying speed is 5.4L/h. Each 1.0cm width three-layer filter strip contains 1.5μg of copper. The copper content values of 20 filter membrane strips are shown in the following table by preparing a standard curve with the copper filter membrane standard substance:

table 3

1 1.507μg 2 1.505μg 3 1.518μg 4 1.489μg 5 1.519μg 6 1.489μg 7 1.513μg 8 1.495μg 9 1.497μg 10 1.483μg 11 1.502μg 12 1.513μg 13 1.533μg 14 1.497μg 15 1.532μg 16 1.521μg 17 1.482μg 18 1.522μg 19 1.501μg 20 1.482μg

The arithmetic mean was 1.505, the standard deviation was 0.016, and there was no significant difference with the u test.

Example 3 manganese three-layer filter membrane strip, solution; manganese nitrate solution, distance between breakpoints 1.5cm, width 4cm, metal pattern width 1.5cm, spraying pressure 1.0MPa, paper speed 0.01m/s, concentration of spraying solution expressed as manganese The elemental weight is 0.5g/L, and the solution spraying speed is 4.8L/h. Each 0.5cm wide three-layer filter strip contains 1 μg of manganese. The manganese content values of 20 filter membrane strips are determined in the following table by using the national standard filter membrane samples to prepare a standard curve:

Table 4

1 1.008μg 2 0.997μg 3 0.992μg 4 1.012μg 5 1.052μg 6 1.031μg 7 1.003μg 8 0.987μg 9 0.989μg 10 0.982μg 11 1.021μg 12 0.994μg 13 1.007μg 14 1.011 μg 15 0.992μg 16 1.005μg 17 1.003μg 18 0.979μg 19 1.011 μg 20 1.009μg

The arithmetic mean was 1.004, the standard deviation was 0.017, and there was no significant difference with the u test.

Claims (10)

1. measure the banded three metafiltration film bars of tenor tearing type in air, it is characterized in that: comprise bolster (1), filter membrane protect (2) on paper, metal spraying filter membrane (4), filter membrane protect paper under (5), described metal spraying filter membrane (4) is positioned at filter membrane and protects under (2) and filter membrane protect paper on paper between (5), three is prolongation banded structure, and two of the elongated strap of three edges are bonded as one by viscose glue, or the elongated strap of three adopts the pressing of viscose glue overall crimping mode to be integrated; Described filter membrane protects (2) on paper, metal spraying filter membrane (4), filter membrane protect paper under the elongated strap that is integrated of (5) three with bolster (1) for axle center is wound around rolling.

2. the banded three metafiltration film bars of tenor tearing type in mensuration air according to claim 1, it is characterized in that: the material of described bolster (1) is plastics or papery, the shape of bolster (1) is hollow or solid cylindrical structural.

3. the banded three metafiltration film bars of tenor tearing type in mensuration air according to claim 1 and 2; it is characterized in that: the both sides of described bolster (1) cylindrical structural are installed with the screening glass of two panels circle; this circular screening glass is positioned at metal spraying filter membrane (4) support metal spraying filter membrane (4) below, and the material of this circular screening glass is plastics or papery.

4. the banded three metafiltration film bars of tenor tearing type in mensuration air according to claim 1, it is characterized in that: described filter membrane protects (5) under (2), filter membrane protect paper on paper and is miillpore filter with the material of metal spraying filter membrane (4), and spacing distance between the breakpoint line (3) of three is equal, the breakpoint location on breakpoint line (3) is identical.

5. measure the manufacture method of the banded three metafiltration film bars of tenor tearing type in air, it is characterized in that:

Step one, metal spraying filter membrane (4) and filter membrane are protected paper under (5) side of being close to, the pressurization of employing spray head fixed point, even vaporific spray metal salt solusion technique spray, and metal spraying filter membrane (4) and filter membrane protect paper under (5), synchronized even paper feed below the vaporific spout of spray head fixed point pressurization;

Step 2, the metal spraying filter membrane (4) after spraying coating process and filter membrane are protected paper under (5) air-dry in 3s ~ 5s;

Step 3, filter membrane protected (2) on paper be covered in air-dry after metal spraying filter membrane (4) on to pressurize pressing;

Step 4, filter membrane pressing be integrated protect (2) on paper, metal spraying filter membrane (4), filter membrane protect paper under (5) get the breakpoint line (3) of equal intervals with laser breaking machine;

Step 5, by having beaten that filter membrane that breakpoint line (3) pressing is integrated protects (2) on paper, metal spraying filter membrane (4), filter membrane protect paper under the filter membrane of (5) protect (2) on paper, metal spraying filter membrane (4), filter membrane protect paper under the elongated strap that is integrated of (5) three with bolster (1) for axle center is wound around rolling.

6. the manufacture method of the banded three metafiltration film bars of tenor tearing type in mensuration air according to claim 5, it is characterized in that: in described step one, spray head is by controlling the distance with metal spraying filter membrane (4), and spray head spraying liquid pressure controls to spray width.

7. the manufacture method of the banded three metafiltration film bars of tenor tearing type in mensuration air according to claim 5, it is characterized in that: in described step one, spray head is according to metal spraying filter membrane (4) chart drive speed under it, and in the salt solusion of spray metal, metal concentration controls tenor in metal spraying filter membrane (4) unit area.

8. the manufacture method of the banded three metafiltration film bars of tenor tearing type in mensuration air according to claim 5, it is characterized in that: in described step one, spray head spray pressure is 0.5MPa ~ 5.0MPa, metal spraying width is greater than 1/4 of metal spraying material overall width, be less than 3/4 of metal spraying material overall width, chart drive speed is 0.005m/s ~ 0.2m/s, tenor in metal salt solution concentration is 0.1g/L ~ 10g/L, metal salt solution spraying rate is 0.1L/h ~ 10L/h, and metal salt solution pH value is 5.5 ~ 8.5.

9. the manufacture method of the banded three metafiltration film bars of tenor tearing type in mensuration air according to claim 5, it is characterized in that: it is 0.3cm ~ 3cm that described step 4 interrupts dotted line (3) spacing, and breakpoint line (3) live width is less than or equal to 0.2nm.

10. the manufacture method of the banded three metafiltration film bars of tenor tearing type in mensuration air according to claim 5, is characterized in that: in described step 5 filter membrane protect (2) on paper, metal spraying filter membrane (4), filter membrane protect paper under the bandwidth of elongated strap that is integrated of (5) three be 1cm ~ 10cm.