The present paper demonstrates that electrochemical detection (ECD) coupled to ion chromatography and electrospray ionization tandem mass spectrometry (IC-ECD-ESI/MS/MS) can be used to rapidly estimate some indications of the health status of organisms. The lactulose to mannitol ratio (L/M) is used as anon-invasive assay to investigate small intestinal absorption pathways and mucosal integrity. In the present study, an evaluation of the negative effects of nonsteroidal anti-inflammatory drug meloxicam perorally administrated to a group of dogs was carried out by determining the lactulose/mannitol index using the IC-ECD-ESI/MS/MS hyphenated technique. According to the results of the study, meloxicam altered gastrointestinal permeability. Coenzyme Q10 (CoQ10) was tested to determine if it could prevent meloxicam induced gastrointestinal damage and it was found that CoQ10 could be an effective preventive treatment. Furthermore, plasma glucose concentration level was determined to be an indirect indicator of the oxidative state in the blood. To find out the beneficial effects of a double antioxidant combination (alpha-lipoic acid (ALA) and CoQ10) on the total glucose level in chickens, ALA and CoQ10 were provided as food additives in factory farm raised chicken. The results of the pilot study indicate that the glucose level in the plasma of chickens group fed with CoQ10 and ALA was significantly decreased compared to the control group. Ion chromatography (IC) utilizing pulsed amperometric detection (PAD) was compared to ion chromatography coupled with tandem mass spectrometry (MS/MS) as an analytical tool for monitoring the carbohydrate level in biological fluids. In electrochemical detection, the newly developed two-pulse waveform successfully withstands matrix effects in biological samples. Continuous on-line desalting of the high salt concentrations used as the eluent for carbohydrate separation from the anion-exchange column allows coupling of IC and MS techniques. A make-up solution (0.5 mM LiCl) was delivered prior to MS detection for efficient ionization of eluted carbohydrates. Method validation showed that both used techniques are practically comparable and some advantages of each are presented.
COBISS.SI-ID: 4824346
The performed quantitative structure-mobility relationship (QSMR) study has investigated relative migration times of 11 guanidine/imidazoline derivatives, imidazoline receptor ligands, in CE system containing one of CDs, α-, β-, or γ-CD, using linear and nonlinear modeling methods. The analyzed ligands and their inclusion complexes with CDs were fully examined and optimized at semiempirical parametrized model 3 level. The density functional theory, such as B3LYP/6–31G+(d,p)/3–21G(d)/STO-3G(d,p)/STO-3G(d), and ab initio theory, such as HF/3–21G(d)/STO-3G(d), were applied for molecular descriptors computation of the optimized ligands and their complexes. Predictive performances of the developed QSMR models were tested by use of the cross-validation and external test set prediction. Obtained results for Q2 values (0.869, 0.911, and 0.966 for CE system containing α-, β-, and γ-CD, respectively) and root mean squared error of prediction (0.239, 0.242, and 0.288 for α-, β-, and γ-CD, respectively) were proved high predictive power of the proposed models. Finally, multitarget QSMR model, using the ligands descriptors (X) and the relative migration time in presence of α-CD (Y1), β-CD (Y2), and γ-CD (Y3), has been created. The multitarget QSMR model can be used as initial screening predictive tool for CE migration behavior of other related guanidine/imidazoline derivatives in presence of α-, β-, and γ-CD.
COBISS.SI-ID: 5194266
The development of some sensitive assays for quantitative nutritional analysis with an emphasis on selected hyphenated analytical techniques is reviewed in the present paper. The majority of work is dedicated to reviewing the development of analytical tools for routine analysis of carbohydrates and lipids in biological samples, many of them introduced in our laboratory. Handling biological matrices, where endogenous compounds can mask the analyte of interest or where the occurrence of the coelution effect of several compounds present in different amounts hinders the analyte's peak integration, is a major challenge. To overcome this challenge, hyphenated techniques have become widespread in laboratory practice. Some of these techniques are reviewed, with special attention given to an effective on-line interface for thin-layer chromatography-mass spectrometry and on-line coupling thin-layer chromatography-gas chromatography. Recently introduced an on-line coupling of ion chromatograph and hybrid RF/DC quadrupole-linear ion trap mass spectrometer represent an analytical tool for the solution of bioanalytical problems. Developed methods using ion chromatography- pulsed amperometric detection and ion chromatography-mass spectrometry techniques for the quantitative evaluation of sugars are presented. This paper represents basic contributions of our research work connected with some of modern hyphenated techniques. However, this review is restricted to the published papers to be significant developments or improvements during the last three decades.
COBISS.SI-ID: 4786202
Antioxidants in the body are in balance, and form a network that protects living organisms against oxida- tive stress. To prove this hypothesis, we developed suitable methods for assessing the amount of antioxi- dants and their antioxidant activity in the chickens’ plasma, which enable us to explain the overall anti- oxidant status of the animals during the controlled industrial raise. The effects of exogenous coenzyme Q10, and α-lipoic acid on the reduction of oxidative stress in the animal body were assessed. The physical and the health conditions of chickens during the raising period of 40 days were followed. The benefits of additives were estimated through the measured con- centrations of selected low molecular weight antioxidants (coenzyme Q10, α-lipoic acid, α-tocopherol, lu- tein and zeaxathin) and antioxidant enzymes (superoxide dismutase, glutathione reductase), cholesterol and glucose in plasma and measurements of total antioxidant capacity. Quantitative analyses of selected substances were done with different chromatographic, spectroscopic and electrometric methods. The addition of antioxidants has positive effects on the activity of antioxidant network.
COBISS.SI-ID: 5157402