Simple detection of residual enrofloxacin in meat products using microparticles and biochips.

A simple and sensitive method for detecting enrofloxacin, a major veterinary fluoroquinolone, was developed. Monoclonal antibody specific for enrofloxacin was immobilised on a chip and fluorescent dye-labelled microparticles were covalently bound to the enrofloxacin molecules. Enrofloxacin in solution competes with the microparticle-immobilised enrofloxacin (enroMPs) to bind to the antibody on the chip. The presence of enrofloxacin was verified by detecting the fluorescence of enrofloxacin-bound microparticles. Under optimum conditions, a high dynamic range was achieved at enrofloxacin concentrations ranging from 1 to 1000 µg kg(-1). The limits of detection and quantification for standard solutions were 5 and 20 µg kg(-1) respectively, which are markedly lower than the maximum residue limit. Using simple extraction methods, recoveries from fortified beef, pork and chicken samples were 43.4-62.3%. This novel method also enabled approximate quantification of enrofloxacin concentration: the enroMP signal intensity decreased with increasing enrofloxacin concentration. Because of its sensitivity, specificity, simplicity and rapidity, the method described herein will facilitate the detection and approximate quantification of enrofloxacin residues in foods in a high-throughput manner.

Detection of enrofloxacin and its metabolite ciprofloxacin using gold nanoparticles and laser desorption/ionization time-of-flight mass spectrometry.

This paper describes a new, simple, and sensitive method for detecting two fluoroquinolones: enrofloxacin and its metabolite ciprofloxacin, which are widely used as drugs for humans and animals. We utilized gold nanoparticles (AuNPs) and laser desorption/ionization time-of-flight (LDI-TOF) mass spectrometry (MS) with a matrix-free format. An antibody for the drug was immobilized on a chip based on self-assembled monolayers (SAMs) on gold, and AuNPs were decorated with the drug along with a large excess of small molecules, called amplification tags (Am-tags). In this strategy, target drugs in solution bound to the antibody on the chip compete with the AuNP-immobilized drugs. The presence of targets was verified by the amplified LDI-TOF MS signals of Am-tags on AuNPs.

Assessment of Korean consumer exposure to sodium saccharin, aspartame and stevioside.

The dietary intakes of sodium saccharin, aspartame and stevioside were estimated on the basis of food consumption data of the Korean consumer and the concentration of sweeteners in processed foods. Results were compared with the acceptable daily intake (ADI) of sweeteners. Among the 28 food categories for which the application of sodium saccharin, aspartame and stevioside is permitted in Korea, they were detected in 5, 12 and 13 categories, respectively. The estimated daily intake (EDI) of sodium saccharin and aspartame were high in infants and children, whereas the EDI of stevioside was high in adolescents and adults. The most highly consumed sweetener was aspartame, and the highest EDI/ADI ratio was found for sodium saccharin. The main food categories contributing to sweetener consumption were beverages, including alcoholic beverages. For most Korean consumers, the EDIs were no greater than 20% of their corresponding ADI; however, the EDI of sodium saccharin for conservative consumers aged 1-2 years reached 60% of their ADI.

Assessment of exposure of Korean consumers to acesulfame K and sucralose using a stepwise approach.

Using a stepwise assessment of the exposure of Korean consumers to acesulfame K and sucralose, theoretical maximum daily intakes of the sweeteners were calculated using the Budget screening method, which resulted in values greater than the acceptable daily intakes (ADIs). Accordingly, the daily intakes of the sweeteners based on food consumption data and concentrations determined by instrumental analysis of 605 food samples were estimated for the more refined approach. The estimated daily intakes (EDIs) of all ordinary consumers were lower than the ADI, which was considered safe. However, for infants and 95th percentile high-level consumers (especially those who choose sucralose-containing foods), the EDIs of sucralose were very close to and higher than the ADI. Therefore, the sucralose concentration in sweetened beverages should be reduced; this would benefit the health of both high-level consumers and infants.