Recent Update: Limited time only! Get 30% off for samples that fail the test with bulk orders (≥ 4 samples)! Learn more.
The Shake Flask Method measures the dissolved organic carbon (DOC) removal during aerobic biodegradation in a shaking flask setup. The degradation percentage is calculated as the ratio of DOC removal to the initial DOC dosed into the test medium.
The carbon content of the test substance and its purity may be known to calculate the dosage. Information on the toxicity of the test substance is helpful in determining the appropriate dosage so that the material does not inhibit bacteria at the concentration tested.
This method is capable of testing samples that are highly soluble (> 50 mg DOC/L), non-volatile, and non-adsorbing.
Compared to the Closed Bottle Method, the Shake Flask Method has a few limitations such as much higher substance dosage (but the inoculum is the same), and incapable of handling volatile or adsorbing materials. Therefore, the Closed Bottle Method is usually our preferred method.
The Closed Bottle Method measures the dissolved oxygen (DO) consumption during aerobic biodegradation in a closed bottle setup without head space. The degradation percentage is calculated as the ratio of DO consumption to the theoretical oxygen demand (ThOD).
The formula of the test substance and its purity may be known to calculate the ThOD. If the ThOD cannot be obtained, the chemical oxygen demand (COD) may be experimentally determined and used as a less satisfactory alternative.
Information on the toxicity of the test substance is helpful in determining the appropriate dosage so that the material does not inhibit bacteria at the concentration tested.
This method is capable of testing samples that are highly soluble, volatile, and/or adsorbing.
Different testing methods are applicable for materials with different properties. Below is a summary of the applicability of OECD 306. Please check our Method Selection Guide to select the most appropriate method for your materials. You can also find the applicability for many other methods on Aropha Resource Center
|Test||Analytical method||Sample info required *||Poorly soluble||Volatile||Adsorbing|
|OECD 306 (I) (Shake Flask Method)
||Organic carbon content *
|OECD 306 (II) (Closed Bottle Method)
||ThOD or COD *
*"Sample info required" is the information needed to calculate the biodegradation percentages. This must be available for a selected method.
*"Organic carbon content" is the ratio of the organic carbon weight to the weight of the sample. It can be calculated by the sample formula (e.g., acetic acid C2H4O2, carbon content is 12*2/(12*2+1*4+16*2)=40%). Try our Online C% Calculator. If the formula is unknown, we can send the sample out to a third party lab for you for analysis (normally $110 per sample with a 10-day turnaround time).
*"ThOD" can be easily calculated based on the formula of the sample. Try our Online ThOD Calculator.
*"COD" can be used as an alternative to ThOD if the formula of the material is unknown. We provide COD analysis at Aropha.
To learn more about different types of biodegradation tests, their applicability, biodegradation mechanisms, and many other information such as case studies, publications, and blogs, please check our Aropha Resource Center