Indoor air TVOC (total volatile organic compounds) hazard and detection methods - Database & Sql Blog Articles

Indoor air

TVOC

(

Total volatile organic compounds

Hazard and detection method

TVOC

Harm to the human body

TVOC

It can be odorous, irritating, and some compounds are genotoxic. Currently believed that

TVOC

Can cause imbalance of immune level, affecting central nervous system function and digestive system function. Lighter skin irritation, sore throat, headache, dizziness, lethargy, chest tightness, fatigue, loss of appetite, nausea and other symptoms. In severe cases can cause bronchitis, allergic asthma, pneumonia, pulmonary edema. In severe cases, it can damage the function of the liver and hematopoietic system, and allergic reactions occur.

Generally considered to be a normal, non-industrial indoor environment

TVOC

The concentration level does not cause tumors and cancer in the human body. when

TVOC

Concentration is

3.0-25 mg/m3

When it occurs, it can cause irritation and discomfort. When combined with other factors, headache may occur.

;

when

VOC

Concentration is greater than

25 mg/m3

In addition to headache, other neurotoxic effects may occur.

TVOC

Detection method

Here we only introduce in detail

TVOC

Thermal desorption

/

Capillary gas chromatography.

TVOC

The detection principle is:

TenaxTA

As an adsorbent

TVOC

The sorbent tube collects a volume of air sample, and the volatile organic compounds in the air stream remain in the sorbent tube. After sampling, the adsorption tube is heated to absorb volatile organic compounds, and the sample to be tested enters the capillary gas chromatograph with an inert carrier gas. After capillary separation under certain conditions,

FID

Detection, workstation recording of spectra and data, qualitative time, peak height or peak area quantitation.

The specific analysis conditions and processes are as follows:

1

Using atmospheric samplers and

TVOC

Adsorption tube to the site sampling:

0

,

5L/min

Pick

20min

which is

10L

atmosphere. That is

10L

Atmosphere

0

,

5L/min

The flow rate passes through the adsorption tube, and the total volatile organic compounds in the air are adsorbed in the adsorption tube and brought into the laboratory for detection;

2

Start the gas chromatograph:

0

,

32mm

*

50mTVOC

Capillary column

FID

:

260

°C; vaporization:

260

°C; column room:

50

Constant °C

10min

Take

5

°C

/min

Cheng Shengzhi

250

°C;

250

°C to peak completion; sensitivity and attenuation:

103

*

1

; calibration: the content will be

100mg/mL

Standard sample

1

μ

L

Calibration with a scaler into the adsorption tube, with

100mL/minN2

blow

5min

This tube is the standard adsorption tube; thermal desorption temperature:

300

°C, pyrolysis

30

Second, injection

5min

After returning to the pyrolysis instrument, the split ratio

50

:

1

3

According to the above conditions, the standard adsorption tube is first prepared. After the drawing, the calibration curve (factor) is obtained by the external standard method, and then the sample is taken in the adsorption tube under the same chromatographic conditions.

TVOC

Chromatograms and qualitative quantification.

4

, calculation:

a

According to the above method, the integral result table can be directly obtained in the sampling tube.

TVOC

Content of each component

M

, the unit is μ

g

;

b

Find

TVOC

Total amount

M

Total =

M1+M2+M3+----Mi+M

(

g

). Set total volatile content

M

Real =

f(

Toluene

)

×∑

A

The amount of material that is not identified as qualitative is calculated as the correction factor for toluene.

c

Find the actual air

TVOC

Total amount

M

Real =

M

total

--M

Blank total

d

Find the measured indoor air

TVOC

concentration

C

total

==M

Real (μ

g

)

/V0

(

L

)

Mg/m3

)

V0

To correct the sample volume to the standard state,

V0==V

Mining ×

(T0/273+t)

×

(P/P0)(L)

5

, judgment and report: according to the calculation results

C

Always rely on

GB

The indicator is judged, the conclusion is drawn, and a report is issued.

Attached to Beijing Huasheng Spectrum Instrument Indoor Environment

(TVOC)

Test dedicated gas chromatograph configuration:

equipment name

Models and Specifications

unit

Quantity

Gas Chromatograph

Host

+FID+

Filling system

+

Capillary system

station

1

Host

+FID+

Filling system

Host

+FID+

Capillary system

station

2

Chromatography workstation

BF-2002TVOC

Special edition

Dual channel

station

1

Air generator

0

~

3000ml/min

station

1

Hydrogen generator

0

~

310ml/min99.999%

station

1

nitrogen bottle

High purity nitrogen

99.999%

Pressure reducing valve

set

1

ATDS-6000

Thermal analyzer

Analysis

-

activation

6

Branch pipe

-

Analog sampling

-

Backflushing machine

station

1

Spectrophotometer

Detection of formaldehyde and ammonia

station

1

Measuring instrument

FD216

station

1

Dual gas path sampler

QC

series

0.1

~

1.5L/min

Continuously adjustable timing:

1

~

99min

station

1

QC-6H

Constant current

Sampling flow:

0.4

~

0.6L/min

station

1

BS-H2

Constant current

Working flow range:

100

~

500ml/min

station

1

Empty box pressure gauge

DYM3

station

1

thermometer

TES1360

station

1

Digital blast drying oven

9030MBE

station

1

Quartz double distilled water meter

SZ-93

station

1

Electronic balance

Accuracy:

0.1mg

; weighing range:

200g

station

1

Sample box

Packing equipment such as absorption tube and sampling tube; equipped with aluminum alloy bracket

One

1

TVOC

Special column

United States

KB0.32mm*50m*1u

support

1

Benzene special column

3mm*2M

support

1

Tenax

Adsorption tube

200mg50

support

/

Box (number of options)

box

1

Activated carbon sampling tube

50

support

/

Package (quantity matching)

package

1

Bubble absorber

10ml

(quantity matching)

support

1

Glass plate absorber

10ml

(quantity matching)

support

1

TVOC

Standard solution

10

,

100

,

1000ug/ml

set

1

Benzene standard solution

2ml

support

1

Benzene standard gas

2L5

Component

bottle

1

Phenol reagent

5g

bottle

1

Formaldehyde solution

20ml100mg/L

or

2ml10.2mg/ml

support

1

Ammonia solution

20ml500mg/L

support

1

Beijing Huasheng Spectrum Instrument Co., Ltd.