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A test method for formaldehyde content in concrete admixture

A technology for concrete admixtures and testing methods, which is applied in the direction of measuring devices, instruments, scientific instruments, etc., can solve problems such as inability to achieve rapid measurement, influence of measurement results, and operator inconvenience, so as to broaden testing methods, improve testing efficiency, and strengthen The effect of rinsing capacity

Active Publication Date: 2020-10-09
KZJ NEW MATERIALS GROUP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This test is not interfered by acetaldehyde, and has the advantages of simple method, good selectivity and reproducibility, and small error, but this test method also has certain shortcomings, such as distillation is required, and in order to prevent the distilled formaldehyde from volatilizing at high temperature, The distillate outlet needs to be cooled with ice cubes, which is tedious and time-consuming, and brings great inconvenience to the operator; the formation of the complex needs to be kept at a constant temperature of 60 ° C for 30 minutes. If it is at room temperature, it will take longer and cannot be realized. Its rapid determination and in the presence of SO 2 Testing in a different environment will also have a certain impact on the measurement results

Method used

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  • A test method for formaldehyde content in concrete admixture
  • A test method for formaldehyde content in concrete admixture

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Experimental program
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Effect test

Embodiment 1

[0029] 1.1 Instruments and reagents

[0030] Metrohm China Co., Ltd. Metrohm 883 ion chromatography system; IonPac AS18 anion analysis column; IonPac AG18 guard column; AERS500 4mm anion suppressor; Mettler Toledo Instruments (Shanghai) Co., Ltd. electronic analytical balance; formic acid (standard Substance); Tween20 (analytical pure); OP-10 (analytical pure); DMSS (analytical pure); MAPK (analytical pure); 1-hexyl-2,3-dimethylimidazolium hexafluorophosphate ionic liquid; Dodecyl-3-methylimidazolium hexafluorophosphate ionic liquid; 1-butyl-2,3-dimethylimidazolium tetrafluoroborate ionic liquid; 1-octyl-3-methylimidazolium bis(tri Fluoromethylalkanesulfonyl) imide salt ionic liquid; choline; guanidine; quaternary ammonium base; sodium methoxide; sodium ethoxide; potassium ethoxide; sodium tert-butoxide; hydrogen peroxide; sodium peroxide; potassium peroxide; laboratory The water used is ultrapure water; the samples used are concrete admixture samples 1#, 2#, 3#, purchased fr...

Embodiment 2

[0038] 1.2 Sample pretreatment

[0039] Accurately weigh 7.008g of sample 2# into a headspace vial, add 2mL of OP-10, seal and soak for 12min. Then use a 10 μL microsyringe to extract 3 μL of 1-dodecyl-3-methylimidazolium hexafluorophosphate ionic liquid, insert it into the space above the sample to be tested in the headspace vial, extract the headspace for 7 minutes, and draw the droplet back into the microsyringe. The operation is repeated until the extraction is completed, and the extracted sample solution is obtained. Then add 1.5 mL of 0.2% guanidine solution and 0.6 mL of 0.1% sodium peroxide solution, shake and extract for 35 minutes to obtain the working solution of the sample to be tested.

[0040] 1.4 Sample test

[0041] The chromatographic conditions are: IonPac AS18 anion analysis column, 4×250mm, IonPac AG18 guard column, 4×50mm, AERS5004mm anion suppressor, suppressor current is 50mA, conductivity detector, column temperature is 35℃, injection volume is 15μL ...

Embodiment 3

[0044] 1.2 Sample pretreatment

[0045] Accurately weigh 9.012g of sample 3# into a headspace vial, add 4mL of DMSS, seal and soak for 15min. Then use a 10 μL micro syringe to extract 3 μL of 1-butyl-2,3-dimethylimidazolium tetrafluoroborate ionic liquid, insert it into the space above the sample to be tested in the headspace bottle, extract the headspace for 8 minutes, and withdraw the droplet Micro-syringe, repeat the operation, the extraction is completed, and the extracted sample solution is obtained. Then add 2 mL of 0.2% quaternary ammonium alkali solution and 0.6 mL of 0.2% potassium peroxide solution, and extract in a constant temperature water bath at 50°C for 30 minutes to obtain the working solution of the sample to be tested.

[0046] 1.4 Sample test

[0047] The chromatographic conditions are: IonPac AS18 anion analysis column, 4×250mm, IonPac AG18 guard column, 4×50mm, AERS5004mm anion suppressor, suppressor current is 50mA, conductivity detector, column temper...

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Abstract

The invention discloses a method for testing formaldehyde content in concrete admixtures, which comprises the following steps: (1) pretreatment of concrete admixture samples; (2) drawing of standard working curves; (3) calculation of formaldehyde concentration. The present invention adopts the combined use method of ionic liquid headspace single-drop liquid-phase microextraction to pretreat the concrete admixture, so that the residual formaldehyde in the concrete admixture is separated without going through the step of distillation, so as to avoid the target substance in the distillation process. Overflow, reduce measurement error, simple operation steps, save time, easy to use the instrument, and strong operability.

Description

technical field [0001] The invention belongs to the technical field of building material detection, and in particular relates to a method for testing formaldehyde content in concrete admixtures. Background technique [0002] Formaldehyde is a colorless gas with a strong pungent odor at room temperature, and is easily soluble in water, alcohol and ether. Formaldehyde has high toxicity to human body and animals, has been identified as carcinogenic and teratogenic substances by the World Health Organization, and is also one of potential strong mutagenic substances. However, formaldehyde is widely used in the production of resins, plastics, rubber, interior wall coatings, concrete admixtures, plywood and adhesives due to its easy preparation, wide application and low price. In recent years, concrete admixtures have been widely used in construction projects to improve the working performance of concrete. With the widespread use of admixtures, some harmful substances in the admi...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01N30/96G01N30/06
CPCG01N30/06G01N30/96G01N2030/062
Inventor 李格丽方云辉钟丽娜郭元强林添兴
Owner KZJ NEW MATERIALS GROUP CO LTD