biocomma
As a vendor of IAC cartridges, we helped many customers for establishing and improving mycotoxin testing methods. Below are some experiences we like to share.
Customer 1: A food-test institute in Shenzhen
Problem Description:
Customer did not get any results by using the 2nd method of “GB 5009.22-2016 National Food Safety Standard Determination of Aflatoxin B and G in Food”.
Investigation:
The customer performed the sample preparation protocol exactly same as this standard method and used totally same chromatographic conditions.
Analysis:
Firstly, we suggested the customer ensuring to use enough deuterogenic reagents. Since the trifluoroacetic acid has high volatility, if without enough volume, the derivatization of aflatoxin B1 would be affected.
Secondly, the gradient settings of mobile phase in some instruments would possibly result in such problem.
Solution:
Adopting our suggestion, after excluding the cause of trifluoroacetic acid, the customer adjusted the gradient settings of mobile phases for elution procedure.
Customer 2: A 3rd Lab in Guangzhou
Problem Description:
The recoveries of Copure® Immunoaffinity cartridges for ochratoxin A were over 120%.
Investigation:
When doing the analysis, the customer have used different solvents for the mobile phase.
Analysis:
The matrix effect could highly possible be the cause for such problem.
Solution:
Suggested the customer using the initial mobile phase as the re-dissolved matrix for analysis.
Customer 3: A 3rd Analysis Lab in Shenzhen
Problem Description:
For the vomitoxin tests, the recoveries of control group did not have any results.
Investigation:
When configurated the internal standard solution, the customer used the methanol solution instead of the mobile phase solution.
Analysis:
The high concentration of methanol in solution would break the binding of the antibody to antigen.
Solution:
Customer changed to use the mobile phase solution as the matrix of the sample.
Additional tips for the concentration of sample matrix:
According to our experiences, generally, for vomitoxin tests, it is suggestive that the concentration of methanol shall not over 5%, and for the aflatoxin B1 and total aflatoxin tests, the concentration of methanol shall below 25%
Customer 4: A 3rd Lab in Dongguan
Customer Questions:
When performed the Total Aflatoxin test, why the recoveries of the procedure with drying and without drying were quite different after elution by 2% methanol in solution? And Why the drying procedure is barely necessary for SPE while inverse for immunoaffinity method?
Answers:
For the elution process of SPE method, generally, the volume of eluent solution is about 2-5 times of the volume of the sorbent, which could ensure quite full elution.
While, for the immunoaffinity, the volume of eluent solution is small, which could easily result in residuals into the sorbent bed if do not drying process and affect to the recoveries.
Additional tips:
For the elution of the immunoaffinity, it is suggestive to control the flow rate to be 1 drop/second.
Customer 5: A 3rd Institute in Guangdong Province
Questions:
(1) When using the immunoaffinity cartridges, whether the buffer solution should be removed?
(2) Why the flow rate of should be in controlling during the binding processing?
Answers:
(1) Removal of buffer solution would not make much difference for the final results. While, the buffer solution is not necessary to be removed and could be uploaded for binding directly.
(2) Too high flow rate during binding, elution would possibly result in low recoveries. For the immunoaffinity, it is suggestive to control the flow rate of binding to be 1 drop/second and the flow rate of elution to be 1~2 drops/second.
For more information about Copure® IAC cartridges for mycotoxin testing, please contact info@biocomma.com.
About Biocomma
Biocomma Limited, founded in 2006, is a leading manufacturer of filtration, sample preparation, oligo synthesis and nucleic acid purification products, based on its two technology platforms of porous plastic filters and separation materials. Biocomma is ISO9001:2015 certificated and a National High and New Tech Enterprise.
Biocomma owns one filter manufacturing facility, two assembly facility and one R & D center, supplying more than 1,500 products. For the past eleven years, we have served over 4,000 customers and provided OEM and customization services for dozens of well-known brands around the world.