Validation of Multi-residue Analytic Method for Detection of Some Biocides in Different Agricultural Commodities

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Hazarhun G., Gümül B., Maden B., Ayyıldız K., Ertaş Özkan S., Arabacı E. E., ...More

8th International Food Safety Congress, İstanbul, Turkey, 9 - 10 May 2024, vol.1, no.1, pp.51-52

  • Publication Type: Conference Paper / Summary Text
  • Volume: 1
  • City: İstanbul
  • Country: Turkey
  • Page Numbers: pp.51-52
  • Bursa Uludag University Affiliated: Yes


Hypothesis: Didecyldimethylammonium chloride (DBAC) and benzalkonium chloride (BAC) are multi-use biocides that are used for surface cleaning. Since these compounds show broad spectrum activity against bacteria and fungi, they are widely used in greenhouse disinfections. These chemicals may be environmentally persistent depending on local conditions. They are highly toxic to aquatic invertebrates and moderately toxic to fish and mammalian if ingested. Additionally they display adverse effects on reproduction, development and nervous systems of mammalians. They may contaminate fresh vegetables and fruits, and European Union (EU) authorities recommend monitoring their residues on various agriculture commodities. The aim of this study was to validate an analytical method for the detection of BAC and DBAC with their C10-C18 and C8- C12 homologues using LC-MS/MS and QuECHeRS extraction in 4 different matrices (raisin, lentil, chestnut and tomato). Methods: The raisin, lentil, chestnut and tomato samples without any chemicals were purchased by Perla Fruit Company. The extraction of the compounds on samples was performed by using a suitable kit for fresh fruit and vegetables according to AOAC 2007.01 QuEChERS method. Briefly, fifteen grams of sample were mixed vigorously for 1min with 15mL acetonitrile. Then, anhydrous magnesium sulphate (6g) and sodium acetate (1.5g) were added to the tube contents and shaken vigorously for a further 1min. The tubes were then centrifuged at 4000 rpm for 1min. The supernatants were carefully transferred into 15mL falcon tubes containing anhydrous magnesium sulphate (1.2 g) and PSA (400mg). The tubes were vortexed for 30 s and centrifuged at 4000 rpm for 1min. The supernatants were passed through 0.2mm membrane filters and transferred into auto-sampler vials for LC–MS/MS. The validation of each chemical was evaluated according to SANTE/11312/2021 Guidelines. Linearity was tested with six levels ranging from 2.5 to 250mg L−1. Recovery rates and precision values were calculated using the results from two analysts at five different times for two different levels (10 and 50mg L−1). 2.5 mg L−1 of the compounds was used for calculation of limit of quantitation (LOQ) values. Results: The linearities of DBAC and BAC and their homologues were quite confident (r2 = 0.997-0.999) for all matrices. The LOQ values of DBAC and BAC were 2.70-3.04 and 2.61-4.51 µg kg-1, respectively. The detection limits were under their Maximum Residue Limits (MRL: 50 and 100 µg kg-1) for DBAC and BAC and their homologues, respectively. The recovery rates of the compounds from all matrices for two spike levels (10 and 50 µg kg-1) were calculated between 93-97% and 95-100% for DBAC; 79-99% and 85-98% for BAC, respectively. The recovery percentages are found within the confidential interval (70-120%) mentioned in SANTE/11312/2021 Guidelines. The highest repeatability RDSr and reproducibility RDSR values for two spike levels (10 and 50 µg kg-1) were 11.04% and %12.91, respectively. All RSD values were lower than the SANTE’s limit (<20%). Discussion: The validation data of both compounds and homologues for different matrices represented four groups obtained in LC-MS/MS analysis was compatible with the SANTE/11312/2021 Guideline. The optimized method provided fast and reliable detection of these biocides on different agricultural commodities and can be used for residue monitoring programs.