Simultaneous determination of ampicillin and tetracycline in milk by using a stopped-flow/T-format spectrofluorimeter

J of Applied Polymer Sci

Hua

et al. 2014

A novel molecularly imprinted electrochemical sensor was developed for the sensitive and selective determination of ampicillin (AMP). The sensor was prepared on a platinum electrode modified with multiwalled carbon nanotubes (MWCNTs), gold nanoparticles (AuNPs), and a thin film of molecularly imprinted polymers (MIPs). MWCNTs and AuNPs were introduced to enhance the sensor's electronic transmission and sensitivity. The molecularly imprinted polymer (MIP) was synthesized using AMP as the template molecule, methacrylic acid as functional monomer, and ethylene glycol maleic rosinate acrylate (EGMRA) as cross‐linker. The performance of the proposed imprinted sensor was investigated using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The results showed that the imprinted film displayed a fast and sensitive response to AMP. Under optimal conditions, response peak current had a linear relationship with the concentration of AMP in the range of 1.0 × 10−8 mol/L to 5.0 × 10−6 mol/L and a detection limit of 1.0 × 10−9 mol/L (S/N = 3). This imprinted sensor was used to detect AMP in food samples with recoveries of 91.4–105%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40613.

Section: Introductionmentioning

confidence: 99%

Molecularly imprinted electrochemical sensor for the determination of ampicillin based on a gold nanoparticle and multiwalled carbon nanotube‐coated pt electrode

Wei

J of Applied Polymer Sci

Hua

et al. 2014

“…Various methods, such as high-performance liquid chromatography (HPLC), 4,5 spectrophotometry, [6][7][8][9] fluorescence method, [10][11][12] chemiluminescence 13,14 and capillary electrophoresis 15 etc., have been reported for the determination of penicillin antibiotics. Among them, HPLC is very useful for the determination of trace penicillin antibiotics in some complicated samples such as human plasma, 4 human serum, 16 bovine milk 17 and feedstuff, 18 while it needs complex pretreatment.…”

Section: Introductionmentioning

confidence: 99%

A Highly Sensitive Resonance Rayleigh Scattering Method for the Determination of Penicillin Antibiotics with Potassium Ferricyanide

Duan

et al. 2008

Chin. J. Chem.

Heated in a boiling water bath, penicillin antibiotics such as amoxicillin, ampicillin, sodium cloxacillin, sodium carbenicillin and sodium benzylpenicillin could react with K 3 [Fe(CN) 6 ] to form combined products in a dilute HCl medium. As a result, resonance Rayleigh scattering (RRS) intensity was enhanced greatly and new RRS spectra appeared. The maximum scattering wavelengths of the five combined products are all located at 330 nm. The scattered intensity increments (∆I) of the combined products are directly proportional to the concentrations of the antibiotics in a certain range. The methods exhibit high sensitivity, and the detection limits for the five penicillin antibiotics are between 4.61 and 5.62 ng•mL -1 . The spectral characteristics of RRS and the optimum reaction conditions were investigated. The mechanism of reaction and the reasons for the enhancement of resonance light scattering were discussed. The effects of coexisting substances have been examined, and the results indicated that the method had a good selectivity. It can be applied to the determination of penicillin antibiotics in capsule, tablet, human serum and urine samples.

“…Consequently, thorough separation and cleanup might not be needed, leading to improved productivity. TRL methods have been successfully developed for analysis of TCs in a variety of biological matrices, for example, serum and urine (23,24), milk (25,26), chicken breast (27), and catfish fillet (28). With a small C18 layer that functioned first as an extraction/cleanup sorbent and then as a TRL substrate, we have simplified extraction, enrichment, and cleanup to two immersion steps using TC in milk as a model analyte.…”

Section: Introductionmentioning

confidence: 99%

Hyphenation of Sorbent Extraction and Solid-Matrix Time-Resolved Luminescence Using Tetracycline in Milk as a Model Analyte

Chen

2004

J. Agric. Food Chem.

Hyphenation of sorbent extraction and solid-matrix time-resolved luminescence (TRL) was demonstrated using tetracycline (TC) in milk as a model analyte. The performance of a C18-impregnated silica layer was evaluated as both an extraction sorbent and a TRL substrate. To extract TC, a 10 x 6 mm glass-backed C18 layer was dipped into a 10 mL milk sample for 10 min followed by a 3-min water immersion for cleanup. The sorbent was then spotted with a TRL reagent solution at pH 9 that contained 5 mM europium nitrate and 5 mM EDTA. After a brief desiccation period, TRL was measured directly on the sorbent surface with a commercial fluorescence spectrophotometer. By eliminating the need to elute the analyte from the sorbent, organic solvent was not needed and sample preparation was greatly simplified. The integrated signal showed a linear dependence (R(2) = 0.9938) on TC concentration in the 0-3000 microg/L range. The same protocol was applicable to screening TC in fat-free, 2% low-fat, and whole milk at 300 microg/L, the US. regulatory tolerance level set by the Food and Drug Administration (FDA). This easy, fast, and low-cost screening method is friendly to the environment and particularly suitable for liquid samples.