Handbook of Solvents - George Wypych - ChemTech - Ventech!

1208 Margot Scheithauer
ρw density, in g/ml, of water at 23°C (ρw = 0.997537 g/ml at 23°C);
ρeci density, in g/ml, of the exempt compound i
1000 conversion factor × 1000 in g/l
Example 4:
Exempt compounds are propanol and ethanol
Solvent water stain 5% solid matter content
(density 0.9 cm 3 ) 20% propanol (density 0.8 g/cm 3 )
10% ethanol (density 0.79 g/cm 3 )
40% other solvent
25% water
VOClwe = [(100-5-25-(10))/{100-0.9(25/1.0)-0.9[(20/0.8)+(10/0.79)]}]× 0.9×1000=825 g/l
Calculated according to DIN ISO 11 890-1, for the same water stain applies (example 4)
after approach 1: 70%
after approach 2: 630 g/l
(propanol and ethanol are treated as VOC)
18.1.3.3.2 VOC content > 0.1 and < 15 %
For VOC content > 0,1 (by mass) and < 15 % the determination is made using gas chromatography
(ISO/DIS 11 890-2). 6 A hot or the cold injection is used depending on the sample
properties.
After assessing the peak areas, the quantitative assessment and evaluation of the VOC
content in the product in its ready-to-use condition, the calculation is made in the simplest
case according to:
i= n
VOC[ g / l] = ∑miρs1000 = 1
i
[18.1.6]
where:
VOC VOC content, in g/l, of the ready-to-use product;
mi mass, in g, of compound i in 1gofthesample
ρs density, in g/ml, of the sample at 23°C
1000 conversion factor × 1000 in g/l.
Table 18.1.2 shows how the application of the various formulae affects the result of
calculation. The VOC contents, calculated after ISO/DIS 11 890, are credible for Examples
2, 3, 4. Values calculated according to ASTM, using ratio solvent - water in Examples 2 and
4, are almost the same as VOC contents calculated according to ISO/DIS.
Only by increasing the solid matter content, the VOC content can be reduced in examples
calculated according to ASTM (cf. Examples 5 and 1), while an increase in the water
content, in spite of the same solvent share, leads to an increase of the ASTM value, because
a higher water content increases the sum of the denominator and consequently increases the
VOC content.
18.1.3.4 Determination of VOC-content in water-thinnable emulsion paints
(in-can VOC)
DIN 55 649 24 describes an approach, which, via the so-called total evaporation method, assesses
the content of volatile organic compounds in water-thinnable emulsion paints (in-can
VOC).