SAFTRA photonics has completed the procedure for the standardisation process of the PickMolTM technology to verify it as an approved reference method for high-sensitive screening of Persistent Organic Pollutants (POPs) (pollutant molecules) in MILK SAMPLES in a mode of MULTIPLEXING ANALYSIS and DIRECT EXTRACTION-LESS DETECTION.

The validation tasks were performed according to the “Validation of environmental test methods CEN guide 2013”. The procedure has presented the reliability of particular measurement steps based on the comparative trials performed by validated HPLC-MS-MS technology.

Based on the previous validations [1],[2], the optimized nano-optical multiplexing chips (PickMolTM Sensing Chip), detection system PickMolTM RAMASCOPE, measurement and evaluation software PickMolTM sw/app, and database of pure forms of detected molecules[3] (PickMolTM database), three different molecules (Paraquat – PQ, Diquat – DQ and Thiram –TR) and six different – randomly selected – commercially available milks (with different milk fat content) were tested to be simultaneously detected in the solutions of the PQDQTR (milk) mixture at concentration level 10-6 M. These solutions were analysed at the same time by HPLC-MS-MS and PickMolTM technology.

By PickMolTM technology 3 measurements (with 3 different chips) for every milk, pesticide’ stock and final mixture’ solutions were carried out. The measurements were repeated for each “Parallel”. In total, the presence of PQ, DQ and TR in milk (10-6 M PQDQTR (milk)) on 54 different chips have been tested. The blank or background sample measurements were provided with the use of pure milk samples (without the pesticide molecules).

The technical report also represents a validation procedure performed by HPLC-MS-MS. The validation process by HPLC-MS-MS required laborious sample preparation and 2 different HPLC-MS-MS condition setups for 3 pesticide molecules (one for Paraquat and Diquat, one for Thiram) to confirm the presence of the pesticides in the tested milk samples.

Conclusions

The technical report demonstrates the standardisation process of PickMolTM technology applied for multiplexing chip based on the verification by HPLC-MS-MS as a standard validated method for POPs/pesticide molecules analyses in milk.

PickMolTM technology is shown as a powerful screening tool for ultrafast analyses for milk contamination. Complete measurement protocol from sampling to data processing is achieved within 10 min and real sample analysis time is ~ 2 minutes.

 

Validation report available upon request: roman.oros@saftra-photonics.org

[1] https://www.saftra-photonics.org/pickmol-technology-applied-for-multiplexing-chip-was-validated-according-to-environmental-test-methods-cen-guide-2013/

[2] https://www.saftra-photonics.org/pickmol-validated-according-to-environmental-test-methods-cen-guide-2013/

[3] http://db.pickmol.tech/#/database