LC-MS/MS and centrifugal ultrafiltration method for the determination of novobiocin in chicken, fish tissues, milk and human serum

Simultaneous determination of the residues of anesthetics and sedatives in fish using LC-QLIT-MS/MS combined with DSPE

Liquid chromatography coupled with quadrupole linear ion trap tandem mass spectrometry (LC-QLIT-MS/MS) technology operated in electrospray ionization (ESI) was developed for tracing anesthetic (AETs) and sedatives (SDTs) in fish. Sampling procedure was achieved by using acetonitrile extraction followed by dispersive solid phase extraction (DSPE) clean-up. Under the optimized laboratory conditions, reliable qualitative confirmation was obtained through the multiple reaction monitoring-information dependent acquisition-enhanced product ion (MRM-IDA-EPI) mode. Results indicated a favorable linear in the concentration range of 1-100 μg∙kg^-1 (0.1-10 μg∙kg^-1 for MS-222), with regression coefficient not less than 0.9997. The detection limit ranges from 0.03 to 0.4 μg∙kg^-1 (S/N = 3). The validated method was applied to determine AETs and SDTs in fish with satidfied recoveries of 86.3 %-111.7 % and the relative standard deviations (RSD) of 1.9 %-8.9 % (n = 6). Practical samples analysis indicated that the proposed method is simple, rapid, sensitive and accurate for identification of AETs and SDTs.

A monoclonal antibody-based colloidal gold immunochromatographic strip for the analysis of novobiocin in beef and chicken

In this study, a monoclonal antibody (mAb) 1G5 against novobiocin with high sensitivity and specificity was prepared from a newly-designed hapten. According to the results of an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA), the 50%-inhibitory concentration of the anti-novobiocin mAb was 6.9 ng/mL and the cross-reactivity was less than 0.1% to its analogues. Furthermore, a rapid colloidal gold immunochromatographic assay (ICA) was successfully developed for the determination of novobiocin in spiked samples. Two calibration curves were established respectively, for beef and chicken samples. The ICA results showed a visual colorimetric value of 50 ng/mL and a cut-off value of 300 ng/mL in beef samples. The ICA results of chicken samples were almost the same as that of beef. When quantitative detection was performed using a strip reader, the detection ranges for quantitative analysis in beef and chicken were 23.7-287.5 and 19.7-263.8 µg/kg respectively. Recoveries were between 82.7 and 95.3% for beef samples with the coefficient of variation (CV) ranging from 2.5 to 5.1%. Recoveries were in the range of 89.6-105.5% with the CV ranging from 2.9% to 6.3% for chicken samples. Importantly, these results from the ICA were highly consistent with the results obtained by LC-MS/MS. Therefore, this ICA could be used as an alternative means for the rapid determination of NOV in a large number of beef and chicken samples.

Antibiotic residues in milk: Past, present, and future

Now-a-days, various types of antibiotics are being used worldwide in veterinary sector indiscriminately for promotion of growth and treatment of the livestock. Significant portions of antibiotics are released through milk of dairy animals unaltered and exert serious harmful effects on human health. This review evaluates and compare researches on antibiotic residues in milk in published literatures from Pubmed, CrossRef, CAB direct, DOAJ, JournalTOCs, AGRICOLA, ScientificGate, Electronic Journals Library, CAB abstracts, Global Health Databases, Global Impact Factor, Google Scholar, Park Directory of Open Access Journals, BanglaJOL and ISC E-Journals. Antibiotics residue in milk was first detected in 60s and then with an increasing trend with highest after 2,000 (188). The highest no. of works, 49 (21.87%) were accomplished in China, followed by Spain, 30 (13.39%); Germany, 11 (4.91%); and USA, 10 (4.46%). Continent-wise highest researches are published from Europe, 105 (46.88%), followed by Asia, 77 (34.38%); South America, 18 (8.04%); North America, 16 (7.14%); and Africa, 8 (3.57%). For detection, Bovine milk sample is mostly used, 193 (86.16%), followed by ovine, 19 (8.48%); and caprine, 14 (6.25%). Acetonitrile was used in maximum cases (77) for processing the samples. Chromatographic technique was the highest, 115 (51.34%) for detection. Residue of β-lactam group have been detected mostly 133 (36.54%), followed by tetracyclines, 51 (14.01%); fluoroquinolones, 49 (13.46%); sulfonamides, 46 (12.64%); and aminoglycosides, 38 (10.44%). This review observe that antibiotics residues are more common in milk samples that are being manifested in increasing researches on antibiotic detection and measures should adopt to cease this residue.

Determination of marbofloxacin in plasma and synovial fluid by ultrafiltration followed by HPLC-MS/MS

A rapid LC-MS/MS method for the determination of marbofloxacin in plasma and synovial fluid is presented in this study. The method uses a rapid sample preparation which only requires an ultrafiltration step with centrifugal filter devices. The optimized procedure allows a minimal need of sample (175 μL), particularly useful for synovial fluid samples which amount is rather limited; it is simple, rapid and easily applicable providing anyhow a satisfactory clean up, demonstrated by post-infusion experiments. On the other hand to maximize the speed of the analysis an ultrafast chromatographic separation has been obtained by selecting a column of 20 mm; the reduced run-time is suitable for processing numerous samples on a daily basis. Linearity was assessed in the range 5-2500 ng mL(-1); ofloxacin was used as internal standard. LOD and LOQ were respectively 1 and 5 ng/mL. The method was successfully applied to a set of samples generated during an experimental veterinary study.

Is isolation of comprehensive human plasma peptidomes an achievable quest?

The low molecular weight (LMW; <10kDa)* plasma peptidome has been considered a source of useful diagnostic biomarkers and potentially therapeutic molecules, as it contains many cytokines, peptide hormones, endogenous peptide products and potentially bioactive fragments derived from the parent proteome. The small size of the peptides allows them almost unrestricted vascular and interstitial access, and hence distribution across blood-brain barriers, tumour and other vascular permeability barriers. Therefore, the peptidome may carry specific signatures or fingerprints of an individual's health, wellbeing or disease status. This occurs primarily because of the advantage the peptidome has in being readily accessible in human blood and/or other biofluids. However, the co-expression of highly abundant proteins (>10kDa) and other factors present inherently in human plasma make direct analysis of the blood peptidome one of the most challenging tasks faced in contemporary analytical biochemistry. A comprehensive compendium of extraction and fractionation tools has been collected concerning the isolation and micromanipulation of peptides. However, the search for a reliable, accurate and reproducible single or combinatorial separation process for capturing and analysing the plasma peptidome remains a challenge. This review outlines current techniques used for the separation and detection of plasma peptides and suggests potential avenues for future investigation. This article is part of a Special Issue entitled: HUPO 2014.

99mTc-Novobiocin: a~novel radiotracer for infection imaging

The radiosynthesis of 99mTc-Novobiocin (99mTc-NBN) complex and its suitability as a radiotracer for infection imaging was assessed. The radiochemical purity (RCP) of the 99mTc-NBN complex was determined using radio-TLC and radioactive HPLC and biodistribution was studied in artificially infected (A.I.) rats and rabbit, using single well gamma counter (SWGRC) interface with scalar count rate meter (SCRM) and Gamma Camera (γ-CM). The maximum RCP observed for the preparation having 2 mg of NBN, 111 MBq of sodium pertechnetate (Na99mTcO4) and 125 μL of SnF2 (1 μg/μL in 0.01 N HCl) at a pH 5.6 was 98.97±0.40% and remained stable >90% up to 120 min. The activity of the 99mTc-NBN in the infected muscle (TI) was significantly increased from 6.50±0.15 to 19.00±0.17% and decreased in the inflamed muscle (TII), normal muscle (NT), blood, liver, spleen, stomach and intestine within 120 min. The TI/NT and TII/NT ratios were 7.60±1.08 and 1.60±1.14. The Whole Body Static (WBS) images of A.I. rabbit were obtained at 30, 40, 50 and 60 min after the I.V. administration of 111 MBq of 99mTc-NBN to the A.I. rabbit. The stability in saline and serum, higher TI/NT, lower TII/NT ratios and WBS images confirmed the feasibility of the 99mTc-NBN complex as an infection imaging agent.