Volatile Organic Compounds Testing

VOCs are the leading cause of ground-level ozone (air pollution, main ingredient in "smog"). Ground level ozone is formed in the air through the photochemical reaction of sunlight and nitrogen oxides (NOx), facilitated by a variety of photochemical active VOCs. Common sources which may emit VOCs into the air include housekeeping and maintenance products; paints, coatings, inks; building and furnishing materials.

VOCs are emitted as gases from certain solids or liquids that may have short- and long-term adverse health effects. Concentrations of many VOCs are consistently higher indoors (up to ten times higher) than outdoors. VOCs can be emitted via a wide array of products, such as paints, lacquers,wax, cleaning supplies, pesticides, office equipment (printers, copy paper), graphics and craft materials(glues, adhesives), building/furnishing materials, etc. All of these products can release organic compounds while you are using them and, to some degree, when they are stored.

Fig. 1 Various volatile organic compounds (Uragami T, 2014)

Long-term exposure to volatile organic compounds can cause damage to the liver, kidneys, and central nervous system. Short-term exposure to volatile organic compounds can cause eye and respiratory tract irritation, headaches, dizziness, visual disorders, fatigue, loss of coordination, allergic skin reactions, nausea, and memory impairment. Other effects including:

Health Effect

Key signs or symptoms associated with exposure to VOCs

To protect your health, it is best to limit your exposure to these products and materials that emit VOCs.

There are many VOCs detection methods, the most widely adopted method is chromatographic analysis (that is, gas chromatography and high performance liquid chromatography). These methods can qualitatively and quantitatively detect the VOCs in the sample gas. In addition, some VOCs, such as formaldehyde, can be detected by a variety of spectrophotometric methods. Formaldehyde is commonly used in the manufacture of building materials and numerous household products. It is also a by-product of combustion processes. When natural gas, wood, gasoline, or tobacco is burned, formaldehyde is released. The most significant sources of formaldehyde in homes are pressed wood products like particleboard, foam insulation; carpets; drapery fabrics; resins; glues; cigarettes; and un-vented, fuel-burning appliances like gas stoves or kerosene heaters. At room temperature, formaldehyde vaporizes into the air, potentially causing serious health problems. There are also special VOCs detectors in the market, which can detect VOCs on line and reflect the VOCs content in the air more easily.

Fig. 2 Principle of GC-MS

VOC analysis can be customized to your individual needs and may include chemical analysis, content identification, protocol testing, safety analysis, and regulatory consulting services. At Alfa Chemistry , we offer GMW 8081 method for VOCs in automotive dashboard components, ASTM for paints and coating, EPA Method 24/18 for VOC content analysis, etc. We offer versatile detection instruments such as:

TGA

Thermal Gravity Analysis (TGA) is a method of thermal analysis in which the mass of a sample is measured over time as the temperature changes. This measurement provides information about physical phenomena, such as phase transitions, absorption and desorption; as well as chemical phenomena including chemisorptions, thermal decomposition, and solid-gas reactions.

GC-MS

The combination of gas chromatography, one of the most powerful separation techniques, with mass spectrometry, one of the most powerful and versatile detectors, has lead to the most powerful and versatile analytical technique, gas chromatography–mass spectrometry (GC–MS). The former to separate a complex mixture into its components and the latter to deduce the atomic weights of those components. It is particularly useful in identifying organic compounds.

HPLC

HPLC is an efficient method of liquid–solid column chromatography. Using a stationary phase composed of small (3–10 μm) beads increases separation efficiency but requires pumps to force the mobile phase through the column at pressures >300 bar. Unlike gas chromatography, the composition of the mobile phase is often varied with time while the column temperature is held constant. HPLC is suited for coupling with different detectors, particularly in so-called hyphenated techniques, such as HPLC coupled to mass spectrometry (LC-MS).

TOF-MS

Time-of-flight mass spectrometry is a method of mass spectrometry in which an ion's mass-to-charge ratio is determined via a time of flight measurement. The kinetic energy of an ion of mass mis given by mv2/2, so a measurement of its speed v by timing the flight of the ion over a given path determines the mass when the kinetic energy is known, or when the spectrometer has been suitably calibrated. In addition, interest has shifted to the measurement of compounds of larger mass, for which TOF methods are especially well suited.

We also use the advanced international standards and methods such as:

• ASTM Practice D3960-Standard Practice for Determining Volatile Organic Compound (VOC) Content of Paints and related coatings.

• ASTM D 1475-Standard Test Method for Density of Paint ,Varnish，Lacquer, and Related Products.

• ASTM D 2369-Standard Test Method for Volatile Content of Coatings.

• ASTM D 4457-Standard Test Method for Determination of Dichloromethane and 1,1,1-Trichloroethane in Paints and Coatings by Direct Injection into a Gas Chromatograph.

• ASTM D 5095-Standard Test Method for Volatile Content of Silanes, Siloxanes, and Silane-Siloxane blends.

• ASTM D 5200-Standard Test Method for Volatile Content of Solvent-Borne Aerosol Paints.

Alfa Chemistry is professional in environmental analytical testing and research services. We can provide accurate and reliable test results within the time constraint. We have conducted Benzene/Formaldehyde VOC monitoring, indoor air pollutant testing, mold/asbestos in air testing, VOC identification and quantification for different air quality studies. Please feel free to contact us if you have any concern or would like us to perform any air quality testing. Check our instruments list to see our capabilities.

Reference

• Uragami T. (2014) Volatile Organic Compounds. In: Drioli E., Giorno L. (eds) Encyclopedia of Membranes. Springer, Berlin, Heidelberg.