Screening and determination of sulphonamide residues in bovine milk samples using a flow injection system

Fernandes, Flávio Cesar Bedatty; Silva, Aline Santana; Rufino, José Luiz; Pezza, Helena Redigolo; Pezza, Leonardo

doi:10.1016/j.foodchem.2014.06.034

Cited by 16 publications

(5 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From the same bacterial culture, the Kovács assay detected 4.7 Ϯ 0.33 mM, compared to 3.3 Ϯ 0.22 mM using the HIA. The discrepancy in the amounts of indole detected between the two methods is consistent with the known observation that the Kovács assay, although very sensitive, will also detect 3-methylindole (skatole), a common indole analog in biological materials, including bacterial cultures (18)(19)(20)(21)(22)(23)(24)(25). These results suggest that 3-methylindole may be present in the culture medium and is probably responsible for increasing the estimation of indole by a significant percentage (30% in this experiment).…”

Section: Discussionsupporting

confidence: 83%

“…Currently, the Kovács assay (13)(14)(15)(16)(17) is the most widely used method for detecting indole-producing bacteria. However, the key component, para-dimethylaminobenzaldehyde, reacts with a wide variety of indolecontaining compounds (18)(19)(20)(21)(22)(23)(24)(25). As a result of this nonspecificity, the Kovács assay cannot be used to reliably quantitate indole in complex biological samples.…”

mentioning

confidence: 99%

See 1 more Smart Citation

A Rapid and Specific Method for the Detection of Indole in Complex Biological Samples

Darkoh

Chappell

Gonzales

et al. 2015

Appl Environ Microbiol

113

View full text Add to dashboard Cite

bIndole, a bacterial product of tryptophan degradation, has a variety of important applications in the pharmaceutical industry and is a biomarker in biological and clinical specimens. Yet, specific assays to quantitate indole are complex and require expensive equipment and a high level of training. Thus, indole in biological samples is often estimated using the simple and rapid Kovács assay, which nonspecifically detects a variety of commonly occurring indole analogs. We demonstrate here a sensitive, specific, and rapid method for measuring indole in complex biological samples using a specific reaction between unsubstituted indole and hydroxylamine. We compared the hydroxylamine-based indole assay (HIA) to the Kovács assay and confirmed that the two assays are capable of detecting microgram amounts of indole. However, the HIA is specific to indole and does not detect other naturally occurring indole analogs. We further demonstrated the utility of the HIA in measuring indole levels in clinically relevant biological materials, such as fecal samples and bacterial cultures. Mean and median fecal indole concentrations from 53 healthy adults were 2.59 mM and 2.73 mM, respectively, but varied widely (0.30 mM to 6.64 mM) among individuals. We also determined that enterotoxigenic Escherichia coli strain H10407 produces 3.3 ؎ 0.22 mM indole during a 24-h period in the presence of 5 mM tryptophan. The sensitive and specific HIA should be of value in a variety of settings, such as the evaluation of various clinical samples and the study of indole-producing bacterial species in the gut microbiota. Indole is widely distributed in the environment and is a component of diverse important compounds that occur in nature. In the pharmaceutical industry, synthesized indoles and their modified derivatives are popularly known for their medicinal properties. Indole analogs are significant components of a number of products, including vitamin supplements, dye, over-the-counter drugs, flavor enhancers, and perfumery. They are also used in the agricultural and plastics industries. Indole has been shown to play a role in regulating bacterial biofilm formation and virulence and influences diverse physiological processes, including host immune response (1-7).Indole is produced by about 85 bacterial species, including Gram-positive and Gram-negative bacteria, through the enzymatic degradation of tryptophan (8). Once produced, indole can be chemically modified within the same bacterial cell or taken up and modified by non-indole-producing bacteria. The most common naturally occurring indole analog is 3-methylindole (skatole), although other analogs, such as indoxyl sulfate and indole-3-propionic acid, can be found (9-11).Indole production by bacteria is an important phenotypic characteristic that has long been used to differentiate, identify, and diagnose enteric bacterial infections (12). Currently, the Kovács assay (13-17) is the most widely used method for detecting indole-producing bacteria. However, the key component, para-dimethylaminobe...

show abstract

Section: Discussionsupporting

confidence: 83%

mentioning

confidence: 99%

A Rapid and Specific Method for the Detection of Indole in Complex Biological Samples

Darkoh

Chappell

Gonzales

et al. 2015

Appl Environ Microbiol

113

View full text Add to dashboard Cite

show abstract

“…1). 18,19 Analytical measurements were based on the digital images captured by a smartphone application that converts these images into RGB values. Thus, the data were obtained through reectance measured on the G (green) channel because the iminium salt is a magenta-color compound, which is the complementary color to green.…”

Section: Resultsmentioning

confidence: 99%

Preconcentration of sulphonamides in bovine milk by the cloud point extraction method using smartphone-based digital images

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Thus, the analysis conditions were optimized based on studies available in the literature. 84,[87][88][89]…”

Section: Optimization Of the Experimental Parametersmentioning

confidence: 99%

Development of an Environmentally Friendly Extraction Method Using Smartphone-Based Digital Images for the Determination of Total Sulfonamides in Meat Samples

Maroubo¹,

Melchert²

2023

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Sulfonamides (SAs) are low-cost synthetic antimicrobials widely used in veterinary and human medicine to treat diseases and prevent infections. However, long periods of exposure to sulfonamides can cause adverse effects such as allergic reactions. This work aims to study dispersive solid-liquid microextraction as an alternative method for extracting total SAs in meat samples. The procedure uses a colorimetric reaction based on the formation of a pink compound (imine salt) to determine total sulfonamides (sulfamethazine, sulfadimethoxine, sulfathiazole) with digital measurements. A linear response was observed between 33-233 μg kg-1 for total sulfonamides, and the coefficient of variation (n = 11; 67 μg kg-1 of total SAs) and the limit of detection were estimated to be 0.63% and 10 μg kg-1, respectively. For a 750 mg meat sample, 0.11 mg of 4-dimethylaminocinnamaldehyde, 2.60 mg of sodium dodecyl sulfate, and 275 μL of 1-butanol were consumed per sample, and consequently, generating only 335 μL of residue. Besides this, addition-recovery tests were performed, resulting in a 71-100% recovery range, indicating the trueness of the proposed method.

show abstract

Screening and determination of sulphonamide residues in bovine milk samples using a flow injection system

Cited by 16 publications

References 21 publications

A Rapid and Specific Method for the Detection of Indole in Complex Biological Samples

A Rapid and Specific Method for the Detection of Indole in Complex Biological Samples

Preconcentration of sulphonamides in bovine milk by the cloud point extraction method using smartphone-based digital images

Development of an Environmentally Friendly Extraction Method Using Smartphone-Based Digital Images for the Determination of Total Sulfonamides in Meat Samples

Contact Info

Product

Resources

About