在池州酒店晚上怎么叫服务

 Beijing professional formaldehyde removal company_ Indoor air treatment experts_ [Jiemei space]

home page

Formaldehyde treatment project plan

Customer case

Testing and governance cases

Product equipment

Information on formaldehyde removal

Open up wasteland and keep clean

About us

contact us

Standard and method of professional CMA formaldehyde detection

Update Date: December 31, 2019 16:38 Views: 166
What is formaldehyde testing, how to do formaldehyde testing, formaldehyde testing has a door-to-door standard, these problems have been plagued by the decoration of new houses, advocate small editor today to help you solve the mystery of formaldehyde detection.

 Formaldehyde detection
 
Formaldehyde detection refers to the quantitative detection of formaldehyde in air, water, food, clothing, plate, leather, etc. By a specific method or tool. White or easy to wear clothes, especially some jeans, trousers or cotton shirts, have 100% wrinkle resistance and shrinkage. They are molded from glyoxal resin and contain formaldehyde. Formaldehyde has a strong stimulating effect on human skin, which can cause skin eczema and systemic allergy. Song Guangsheng, director of the national indoor environment and environmental product quality supervision and inspection center: the World Health Organization has determined that formaldehyde is a carcinogen.
 
Indoor air test standard:
 
Indoor air test is divided into two standards, one is indoor air quality standard (GB / t18883-2002), the other is code for indoor environmental pollution control of civil building engineering (GB 50325-2010) (2013 Edition).
 
Indoor air quality standard (GB / t18883-2002) was issued by the Ministry of health, and the code for indoor environmental pollution control of civil building engineering (GB 50325-2010) (2013 Edition) was issued by the Ministry of construction.
 
Indoor air quality standard (GB / t18883-2002) is the minimum standard for human settlements, and code for indoor environmental pollution control of civil building engineering (GB 50325-2001) (2006 Edition) is the control standard for environmental pollutants in construction projects.
 
"Indoor air quality standard" GB / t18883-2002 standard covers 19 indexes, while "code for indoor environmental pollution control of civil building engineering" GB 50325-2010 (2013 Edition) only covers 5 indexes.
 
GB / t18883-2002 indoor air quality standard jointly issued by the Ministry of health, the State Environmental Protection Administration and the General Administration of quality supervision, inspection and Quarantine of the people's Republic of China is basically the basic standard for healthy living environment and has no mandatory binding force on building developers, decorators and furniture suppliers. Code for indoor environmental pollution control of civil building engineering (GB 50325-2010) (2013 Edition) jointly issued by the Ministry of construction and the General Administration of quality supervision, inspection and Quarantine of the people's Republic of China is about indoor environmental pollution control of civil construction projects. The inspection conditions with mandatory acceptance criteria for builders and decorators are much more relaxed than those for builders. Although the pollutant concentration limit of the former is slightly lower than that of the latter, the condition of closing doors and windows before inspection is only 1 hour, while that of the latter is 12 hours. Therefore, the final users of a large number of houses, that is, the houses completed and accepted according to the standards of civil construction projects and interior decoration projects, are not equal to the sufficient conditions for the health of human settlements. If furniture is introduced into the interior, the indoor air quality of old and new houses may further decline. The purpose of the test is to measure whether the indoor air quality is in line with the basic standard of living.
 
The national code for design of residential buildings (GB 50096-2011) stipulates that:
 
7.5.3 the activity and concentration of indoor air pollutants in residential buildings shall meet the requirements of table 7.5.3.
 
Table 7.5.3 indoor air pollutant limits for residential buildings
 
Pollutant name, activity and concentration limits
 
Radon ≤ 200 (Bq / M)
 
Free formaldehyde ≤ 0.08 (mg / M)
 
Benzene ≤ 0.09 (m · g / M)
 
Ammonia ≤ 0.2 (mg / M)
 
    TVOC≤0.5(mg/m)
 
Formaldehyde detection method: formaldehyde content in indoor air environment can be divided into:
 
1. AHMT spectrophotometry
 
The main methods of spectrophotometry are acetylacetone method, chromic acid method, MBTH method, by-product red method, AHMT method and so on.
 
    2。 Acetylacetone method: the principle of acetylacetone method is to use formaldehyde, acetylacetone and ammonia to generate yellow compound diacetyldihydrin, and then determine it by spectrophotometry at 412 nm.
 
The main advantages of this method are simple operation, stable performance, small error, no interference from acetaldehyde, and the color solution is stable for 12 hours; the disadvantage is that the sensitivity is low, the minimum detection concentration is 0.25 mg / L, which is only suitable for the determination of high concentration formaldehyde. The disadvantage of this method is that the reaction is slow and takes about 60 minutes; so interferes with the determination (sodium bisulfite can be used as a protective agent to eliminate it). This method is very traditional and widely used.
 
    3。 CTA method was used
 
Chromogenic acid method is also called chromic acid method. Formaldehyde can react with Chromotropic Acid (1,8-dihydroxynaphthalene-3,6-disulfonic acid) in concentrated sulfuric acid solution to form purple compound. The maximum absorption wavelength of the compound is 580 nm, which can be analyzed and determined by spectrophotometry. Changing the concentration of chromotropic acid and adopting different sampling methods can meet the requirements of formaldehyde detection with different concentrations. Using 0.1% chromotropic acid-86% sulfuric acid solution as the absorption solution, the detection limit can reach 20 μ g / L; this method uses 1% sodium sulfite solution to absorb formaldehyde, and the concentration of chromotropic acid is changed to 5%, which is more stable and sensitive. The method is simple and rapid. The disadvantage is that it is difficult to control in the medium of concentrated sulfuric acid, and aldehydes, olefins and nitric oxide interfere with the determination.
 
    4。 Phenol reagent method: the principle of phenol reagent method is that formaldehyde reacts with phenol reagent to form triazine, which is oxidized by iron ion in acidic solution to form cyan compound. Color depth is proportional to formaldehyde content. The molar absorption coefficient of the compound at 630 nm is 7.0 × 104. The method is very sensitive to the determination of formaldehyde, and the detection limit is 0.015 mg / L. The disadvantage of this method is that the presence of acetaldehyde and propionaldehyde will interfere with the determination results. In the presence of sulfur dioxide, the determination results are low, the reaction is limited by temperature, the color development is incomplete when the room temperature is lower than 15, the color development is most complete in 20-35 minutes, and the absorption is stable after 4 hours.
 
5. PRA method:
 
The principle of the method is that sulfite ions and Parafuchsin form a purple complex in the presence of formaldehyde. The maximum absorption peak is 570nm and the detection limit is 50 μ g / L. The advantages of this method are simple and sensitive, and other aldehydes and phenols do not interfere with the determination. The disadvantages are fast fading, low sensitivity, and easy to be affected by temperature. When toxic mercury reagent is used, the chromogenic compound needs at least 60 minutes to achieve stable absorption. The disadvantages of slow color development, low sensitivity and poor stability of spectrophotometry can be eliminated by using flow injection technology.
 
    6。 AHMT method was used
 
The AHMT method is based on the principle that formaldehyde and 4-amino-3-hydrazine-5-mercapto-1,2,3-triazene (AHMT) are condensed in alkaline condition, and then oxidized by potassium periodate to form 6-yl-5-triazene [4,3-b] - s-tetraazaphenyl purplish red compound, which is quantified by color comparison. The method has strong anti-interference ability and has no interference with the determination of hexamethylene, but has serious interference with acetylacetone method, MBTH method and by-product red method. Therefore, this method is an effective method for the determination of formaldehyde released in the process of resin crosslinking. The detection limit is 0.01 mg / m, which is suitable for indoor air detection under normal conditions. The disadvantage of this is that the color of the solution must be uniform with time. The maximum absorption wavelength of the color system is 550 nm. Cobalt and copper interfere with the determination.
 
    7。 Potassium bromate methylene blue method: principle of potassium bromate methylene blue method
 
Inspection instructions:
 
    1。 Selection of environmental protection standards:
 
(1) code for indoor environmental pollution control of civil building engineering (GB 50325-2001) (2006 Edition) is a compulsory national standard and must be implemented. Indoor air quality standard (GB / t18883-2002) is the national recommended standard and non mandatory laws and regulations. This is mandatory only when both parties meet the standards agreed in the agreement.
 
(2) after the decoration is completed, the consumer should check according to the code for the control of indoor environmental pollution of civil building engineering (GB 50325-2001) (2006 Edition); after the furniture is in place or stays for a period of time, the indoor air quality should be tested according to the indoor air quality standard GB / t18883-2002.
 
    2。 Best time to test:
 
Civil works shall be carried out at least 7 days after the completion of decoration works and before the use of the works.
 
It is suggested that the furniture should be inspected one week after the completion of the home decoration project. During this period, adequate ventilation should be ensured to promote the distribution of hazardous substances and to bring the inspection results closer to the actual conditions of use.
 
    3。 The best closing time: for civil construction projects with natural ventilation, the detection and sampling shall be conducted after the outer door and window are closed for one hour; in case of dispute, the closing time of outer door and window shall be 1H (hour).
 
(2) according to the "indoor air quality standard" (GB / t18883-2002), doors and windows are closed for 12 hours (that is, when people sleep normally at night, the doors and windows are closed for more than 12 hours, but not more than 20 hours). Therefore, for air sampling, the detection results of doors and windows closed for 12-20 hours are closer to the facts.
 
    4。 Determination of sampling and testing points:
 
(1) when the usable area of the room is 50 square meters, the number of test points is 1; when the usable area of the room is more than or equal to 50 square meters and 100 square meters, the number of test points is 2; when the usable area of the room is greater than or equal to 100 square meters and 500 square meters, the number of inspection points shall not be less than 3.
 
According to the actual situation of Jiangsu, only one room is needed. When the living room area is less than 50 square meters, only one detection point is needed. If the living room area is more than 50 square meters, it should depend on the actual situation.
 
(3) for a house, there is no detection point in the kitchen and bathroom. It is only recommended to open kitchen and toilet doors during testing and to include their areas in the room or living room to which they are connected. Generally speaking, the house with two bedrooms and one living room has three detection points, that is, each of the two rooms and one hall has one detection point; the house with three bedrooms and one hall has four detection points, that is, each of the three rooms and one hall has one detection point; the apartments with three bedrooms and two halls and the intermediate buildings should be determined according to the actual situation.
 
    5。 Test items:
 
(1) according to the "code for indoor environmental pollution control of civil building engineering" (GB 50325-2001) (2006 Edition), combined with the actual situation in Jiangsu Province, it is suggested that only three items of formaldehyde, benzene and TVOC should be detected in individual residence.
 
(2) according to the indoor air quality standard (GB / t18883-2002), combined with the actual situation, it is suggested that only six items should be inspected for individual Residence: formaldehyde, benzene, TVOC, toluene, xylene and ammonia.
 
    6。 TVOC total volatile organic compounds include: benzene, toluene, p-xylene, m-xylene, o-toluene, styrene, ethylbenzene, butyl acetate, undecane, a total of 9 substances; the concentration of TVOC in CMA test report is the sum of the above nine substances.
share

contact us Contact us

Jiemei space (Beijing) Environmental Technology Co., Ltd
O2o service leading brand of air treatment

24-Hour Hour Hotline

400-826-6606

Company address

Wangjing SOHO, Chaoyang District, Beijing (near Wangjing East Railway Station)

Make an appointment for on-site inspection immediately