Analysis of Multiclass Antibiotics in Lettuce by Liquid Chromatography–Tandem Mass Spectrometry to Monitor Their Plant Uptake

Abstract

The main entry routes of antibiotics in the environment are the application of organic wastes to improve soil quality and the irrigation with recycled water. Once in the environment, antibiotics can be introduced in the food chain through their uptake by crops. This paper describes the development of an analytical method based on ultrasound-assisted extraction for the determination of seven antibiotics in lettuce. The developed method was applied to evaluate antibiotic uptake by lettuce grown in pots fertilized with composted poultry litter doped with a mixture of antibiotics to reach a final concentration of 2.5 µg/g in soil. Lettuce were harvested after 21, 36, and 55 days. Five of the seven studied antibiotics were found in all samples. The highest uptake was found for lincomycin (51 ng/g fresh weight) followed by sulfamethoxazole (44 ng/g fresh weight) and sulfamethazine (21 ng/g fresh weight) in lettuce harvested after 21 days. An important decrease of their levels was observed after 36 days, but these levels remained similar after 55 days. Although levels found in lettuce were low, the presence of antibiotics demonstrates the need for further assessing food safety risks related with the use of soil amendments or irrigation water contaminated with antibiotics.

Uptake of Pharmaceutical Pollutants and Their Metabolites from Soil Fertilized with Manure to Parsley Tissues

“…In the parsley leaf SLE-SPE procedure, the recoveries of the remaining 8 analytes (TC, OTC, DOX, CIP, ENF, LVF, VAN, CLD) were in the range of 67.3% (CIP)–97.1% (OTC) in HQL samples. The recoveries obtained were satisfactory and similar to those previously reported for plant matrices [ 36 , 41 ]. The selectivity of the method was obtained by comparing the chromatograms recorded in MRM mode for the analytes after extraction of the plant material and the blank.…”

“…Analyte recoveries for the single extraction were lower (13.0–45.9%) than for the two-step extraction (14.2–67.8%). Commonly, multiple solvent SLE is used for FCs’ extraction from real samples because, in multi-stage extraction, the distribution coefficient is established at each stage, which makes extraction more effective [ 36 , 37 ]. Additionally, the utilization of solvents of different composition at each step as in L2, allows the extraction of FCs with different polarities [ 6 , 9 , 34 ].…”

“…DOX is mobile in the environment and detectable in soil solutions [ 48 ]. It is the least studied pharmaceutical in the whole group of tetracyclines, where studies have shown that DOX was not detected in lettuce [ 36 ], while it was present in radish and pak choi [ 50 ] when grown in soil supplemented with DOX. The range of concentrations of pharmaceuticals determined in our study (1.0–29.3 ng g −1 ) was comparable to those reported, where 1.6–2.8 ng·g −1 ENF, 0.5–1.5 ng·g −1 , TYL and SMX 0.05–6.8 ng·g −1 were detected [ 10 ].…”

Green and Efficient Determination of Fluoroquinolone Residues in Edible Green Fruits and Leafy Vegetables by Ultrasound-Assisted Extraction Followed by HPLC-MS/MS

“…However, AMs are not completely metabolized and a fraction between 17% and 90% is excreted unchanged in urine and feces, leading to notably widespread contamination of water and soil resources. AMs may enter agricultural fields mainly via the use of recycled water for irrigation due to the incomplete removal of these pharmaceuticals in wastewater treatment processes, and land application of sewage sludge, biosolids and manure as soil amendments or fertilizers instead of chemical fertilizers, which are restricted for organic vegetables [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ].…”

“…Obviously, in the context of the circular economy the agricultural applications of the reclaimed wastewaters and manure is of growing interest and importance. On the other hand, there is a considerable possibility of the introduction—via plant uptake—of AMs into crops, with the non-negligible consequences of the spread of antimicrobial resistance and/or toxic potential effects to consumers because of prolonged low-level exposure to AMs [ 1 , 2 , 4 , 6 , 9 , 10 , 11 ]. Fluoroquinolones (FQs) are one of the most employed class of AMs, adopted both for human and veterinary medicine.…”