Analytical quality assurance in veterinary drug residue analysis methods: Matrix effects determination and monitoring for sulfonamides analysis

© 2014 Elsevier Ltd. All rights reserved. In residue analysis of veterinary drugs in foodstuff, matrix effects are one of the most critical points. This work present a discuss considering approaches used to estimate, minimize and monitoring matrix effects in bioanalytical methods. Qualitative and quantitative methods for estimation of matrix effects such as post-column infusion, slopes ratios analysis, calibration curves (mathematical and statistical analysis) and control chart monitoring are discussed using real data. Matrix effects varying in a wide range depending of the analyte and the sample preparation method: pressurized liquid extraction for liver samples show matrix effects from 15.5 to 59.2% while a ultrasound-assisted extraction provide values from 21.7 to 64.3%. The matrix influence was also evaluated: for sulfamethazine analysis, losses of signal were varying from -37 to -96% for fish and eggs, respectively. Advantages and drawbacks are also discussed considering a workflow for matrix effects assessment proposed and applied to real data from sulfonamides residues analysis

Assessment of chronic pain in the different groups.

Evaluation of the components of CPGS (chronic pain grade scale), namely characteristic pain intensity (A) and chronic pain grade (B), for orthodontic, TMD, and DFD groups. Each column represents the mean, and the lines show the standard deviation (SD). The individual values are depicted as dot plots. **p 0.01 DFD vs. orthodontic; ##p < 0.01 DFD vs. TMD. One-way ANOVA followed by Tukey’s multi-comparison test. DFD, dentofacial deformity; TMD, temporomandibular disorder.</p

Raw data regarding the present manuscript.

Descriptive data and statistical analysis regarding the results presented in the manuscript. (PDF)</p

DEVELOPMENT OF EXTRACTION PROCEDURE FOR ANALYSIS OF SEDATIVES AND β-BLOCKERS IN SWINE KIDNEY

A procedure was developed for determination of 5 sedatives and 14 β-blockers in swine kidney and subsequent analysis by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Three different procedures for extraction were tested, evaluated through recovery studies. The procedure using acetonitrile for extraction and cleanup with freezing at low temperature and dispersive solid phase extraction using 500 mg celite® 545 before the concentration step presented the better results. The dried samples were redissolved with methanol and analyzed using a LC-MS/MS system with electrospray ionization (ESI) operating in positive MRM mode. The recovery values for this procedure were in the 75-88% range. The robustness of the method was tested against small variations. The method was used to analyze carazolol, azaperone and azaperol in collaborative assay, obtaining results close to designed value

Psychological parameters of DC/TMD Axis II.

Evaluation of PHQ-9 (A), GAD-7 (B), and PHQ-15 (C) in the orthodontic, TMD, and DFD groups. Each column represents the mean, and the lines show the standard deviation (SD). The individual values are depicted as dot plots. *p p 0.01 DFD vs. orthodontic; ##p < 0.01 DFD vs. TMD. One-way ANOVA followed by Tukey’s multi-comparison test. DFD, dentofacial deformity; TMD, temporomandibular disorder.</p

Evaluation by Axis I of DC/TMD.

Frequencies (%) of myofascial pain, cephalgia, and articular disorders, as evaluated by DC-TMD Axis I for the orthodontic, TMD (temporomandibular disorder), and DFD (dentofacial deformity) groups.</p

Salivary biochemical markers.

Evaluation of salivary levels of IL-1β (A), glutamate (B), and serotonin (C) in the orthodontic, TMD, and DFD groups. Each column represents the mean, and the lines show the standard deviation (SD). The individual values are depicted as dot plots. **p 0.01 DFD vs. orthodontic. One-way ANOVA followed by Tukey’s multi-comparison test. DFD, dentofacial deformity; IL-1β, interleukin-1β; TMD, temporomandibular disorder.</p