What is the concentration for the mixture of 150mg Glucose and 150mg Glutamic Acid in 1 L water? Is it 198 mg/L or 200 mg/L or else? Can you please show me the calculation? Thank you.

The concentration of the individual components is 150 mg/L. This is different from the BOD value of the standard which is 198 mg/L. This value has a typical acceptance range of ±30.5 mg/L.

how do i obtain the C.O.A. and S.D.S. for this product?

Those documents can be found at http://www.envexp.com/coa and http://www.envexp.com/sds.

What is the CBOD values for gga?

Standard Methods requires that the same acceptance range for GGA results,198±30.5, be applied to all BOD/CBOD analyses. The method advises adjusting the amount of seed used to bring results in that range.

Can I look up the expiration date of a specific lot?

We do not have a searchable database where you can search by expiration dates for products. The expiration date is listed on the Certificate of Analysis (COA) for the specific lot number. You can find the COAs on our website under BOD standard.\r\n\r\n \r\n

I just purchased GGA solution 24X6 mL lot #F029-02. What is the concentraction? 198?

Each vial contains 6mL of the APHA specified concentration of Glucose/Glutamic Acid (150mg/L of Glucose, 150mg/L of Glutamic Acid). When used properly, the standard should give you a result of 198 ± 30.5 mg/L BOD.

What is the pH of the GGA solution?

Standard Methods does not have a pH requirement for the GGA standard. Therefore, we do not specifiy it on our CofA. You would have to test for the pH of the solution. We offer pH meters and testing strips at Environmental Express.

is the desired answer for the glucose glutamic acid cbod5 standard 198+-30mgl

The desired BOD value for the GGA standard is 198 ± 30.5 mg/L BOD.

what is the concentration in PPM of BOD Standard? Is it 300 ppm?

The BOD standard is a mix of two different components, glucose and glutamic acid. The concentration of each of those in the standard is 150 mg/L. However, the concentration of the components is not the same as the BOD value of the standard. When used properly, the standard will give you a result of 198 ± 30.5 mg/L BOD.

The box states \"Refrigerate after opening.\" Does that mean after opening the box of sealed vials or after opening a sealed vial? In other words, do the sealed vials need to be refrigerated?

Those instructions refer only to the individual vial. The sealed vials can be stored on the bench top at ambient conditions.

certificate of analysis

Please see http://www.envexp.com/coa and select the link for your product. We try to keep this up to date but occasionally miss one. If you do not see the COA for your lot please email info@envexp.com with details or call our technical support line at 800-745-8218.

Do you have a certification document for the BOD standard? If so, where can I get a copy?

Please visit http://www.envexp.com/coa for a list of COA\'s for this, and many other, products. If you do not see the lot number that corresponds to your product please contact us directly and we will send you a copy.

Where are your MSDSs located for products?

Our MSDS files are located here - http://www.envexp.com/msds.

How do I get a copy of the certifcate of analysis for a GGA lot?

Most of our certificates of analysis are found at the following link - http://www.envexp.com/coa. If you do not find the lot number listed under the appropriate section please email info@envexp.com with the lot number and catalog number that you need and we will be happy to provide the information you need.

What is the acceptance range for the reference product GGA D1243 for cBOD?

Standard Methods 5210B (2001) section 5. e. deals with the nitrification inhibitor. It instructs that the amount of seed used should be sufficient to achieve GGA results in the range of 198 ± 30.5 mg/L. For that reason we do not list different true values and acceptance ranges for BOD vs. cBOD.

How much volume should be added in 300ml BOD bottle if GGA solution prepared as per APHA standard?

When using the GGA solution that has been prepared according the method, you should have 6 mL of this standard added into a 300 mL BOD bottle. You will add whatever volume of seed is needed from your seed source to achieve the proper oxygen depletion and the remainder of the volume will be done with dilution water.


The BOD value of any substance should never be greater than the COD value within the margin of error for each test. If you have results that seem to indicate otherwise you are probably experiencing some sort of negative interference with the COD analysis or a positive contaminant with the BOD analysis.

Do D1243-BOD: Glucose-Glutamic Acid, 24x6mL vials contain any preservatives? We are having periodic low GGAs.

This solution is made exactly as specified in Standard Methods. There is no preservative available for the GGA standard. The vials are sterilized via autoclave after being filled so that no bacterial activity will degrade the components in the vials.

Besides seed volume variation, what would cause out of range recoveries for GGA?

There are any number of things that could cause out of range G:GA values. Dilution water quality, strength of seed, incubation temperature and probe calibration are some of the more likely causes. I would be glad to discuss some scenarios and trouble shooting with you. Email me at DavidS@envexp.com or call 1-843-576-1133 and we can go over the process.

Does the pH of the check standard solution need adjusted or just set as is? The analysts have been pH adjusting the GGA they make in house; however, I do not recall doing that in my previous position

The pH of all samples for the BOD test should fall within a value of 6.5 - 7.5. Your blanks, GGA, and seed should be analyzed as-is as the method does not call for any pH adjustment of these solutions.

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