Akademik Veri Yönetim Sistemi
8th International Food Safety Congress, İstanbul, Türkiye, 9 - 10 Mayıs 2024, cilt.1, sa.1, ss.51-52
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.