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Determination of Organophosphorus Pesticide Residues in Milk

Abstract

A method for simultaneous determination of 13 organophosphorus pesticide residues in milk samples has been developed and validated. The method is based on the extraction of the sample with acetone and petroleum ether, cleanup by gel permeation chromatography, and solid phase extraction, and determination by gas chromatography with flame photometric detection. The recovery, investigated by analysing blank milk samples spiked with azinphos, chlorfenvinphos, chlorpyrifos, chlorpyrifos-methyl, diazinon, fenitrothion, methacrifos, methidathion, parathion-methyl, pyrazophos, and triazophos at concentrations of 10, 20, and 30 μg/kg, and with parathion and pirimiphos-methyl at concentrations of 25, 50, and 75 μg/kg, ranged from 73.1% to 106.2%. Performance characteristics, such as repeatability and within-laboratory reproducibility expressed as coefficient of variation were less than 20%. Measurement uncertainty was lower than 22% for all validated organophosphorus pesticides. The limits of quantification were 10 μg/kg for all compounds and allowed determination of residues at, or even below, the maximum residue limits set by the European Union. The satisfactory z-score results of international proficiency tests confirm good accuracy, reproducibility, and reliability of the developed method.

Open access
Assessing of landscape potential for water management regarding its surface water (using the example of the micro-region Minčol)

Abstract

The presence of water is one of the decisive factors of landscape’s natural potential. Water affects landscape’s predisposition for agricultural production, water supply available to the wide population and industry (the most important is the yield of water resources). Ponds, lakes and other water areas are zones of recreation and relaxation. Near sources mineral water, several world-famous spas were build. Waterways are also used to generate electricity. Geothermal underground water represents a very significant landscape potential. Determining hydrological potential of the area is important for the regional development. This paper assesses the landscape potential for water management regarding its surface waters in the micro-region Minčol. The micro-region was divided by a square grid, and for each square, we determined the appropriateness of this potential based on score points. The determining evaluation criteria were static reserves of surface water, waterway ranking and annual average discharge. First, we determined the significance (value) of individual criteria (classification characteristics), and then we calculated the values of individual classifiers, which were then multiplied by the value of the individual classifier intervals. The summary of points in each square belongs to a particular degree of suitability for water management based on surface waters. The potential was divided into five degrees (intervals): very unfavourable potential, unfavourable potential, moderately favourable potential, favourable potential and very favourable potential.

Open access
Small terrestrial mammals living along streams acting as natural landscape barriers

Abstract

Riparian stands along streams are important landscape elements – biocorridors, allowing the dispersal of many small terrestrial mammals. Streams are, however, also barriers limiting dispersal, which leads to isolation and population-genetic changes. Communities of small terrestrial mammals (Eulipotyphla, Rodentia) were studied in 2004 to 2006 on five watercourses of varying widths in Central European cultural landscape situated in South Bohemia (Czech Republic). In total, 547 individuals from 10 species were captured by the Capture-Mark-Recapture method (CMR). Yellow-necked mouse (Apodemus flavicollis) and bank voles (Myodes glareolus) were eu-dominant species at all locations. Species diversity and equitability rose with the degree of the barrier – proportional to the width of the stream.

The terrestrial mobility of selected species was also assessed. Apodemus flavicollis indicated overall highest values of mobility, and Myodes glareolus males also scored higher values, however, the width of the stream did not correlate with mobility in these species. The animals crossed water-courses on the order of tens of meters wide in the period of 3 months. The frequency of crossing of Apodemus flavicollis decreased exponentially with the width of the stream and was dependent on population density.

Open access
Evaluation of Genetic Damage in Oreochromis mossambicus Exposed to Selected Nanoparticles by Using Micronucleus and Comet Bioassays

Abstract

The purpose of the present study is to extend knowledge on the adverse effects of nanoparticles by evaluating genotoxicity as environmental risk assessment in Oreochromis mossambicus. Fish were exposed to sublethal concentrations of the selected nanoparticles, namely silicon dioxide (SiO2NPs-12mg/L), aluminium oxide (Al2O3NPs-4mg/L), titanium dioxide (TiO2NPs-16.4mg/L) and iron oxide (Fe3O4NPs-15mg/L) for short-term (24, 72 and 96 h) and long-term durations (15, 30 and 60 days). Genetic damages such as cytoplasmic, nuclear and DNA damage were measured in the erythrocytes of fish by using standard genotoxicity tests such as micronucleus test and comet assay. The frequencies of micronuclei along with nuclear and cytoplasmic abnormalities were scored and compared with the control group. The intensity of micronuclei along with other nuclear and cytoplasmic anomalies are found to be increased significantly (p<0.05) in time-dependent manner in all exposure groups when compared to the control group, thereby indicating chromosomal damage as a result of contact with nanoparticles. The tail length and percent of tail DNA within the comet significantly (p<0.05) increased in time-dependant manner after exposure to all nanoparticles, demonstrating an increase in DNA damage. Taken together, by using micronucleus test and comet assay, it is evident that the selected nanoparticles at sublethal concentrations induced genetic damage in Oreochromis mossambicus.

Open access
The Dynamics of Biochemical Parameters in Blood of Clinically Healthy Holstein Cows from Day 5 before to Day 60 after Calving

Abstract

The peripartal period in Holstein dairy cows is critical, due to the transition from pregnancy to lactation. We have studied the dynamics of biochemical parameters from day 5 before to day 60 after calving. The study included 10 multiparous Holstein cows, examined at days -5, 5, 10, 30 and 60 relative to calving. Blood samples were taken from vena jugularis. Analyzed biochemical parameters were glucose, triglycerides, total cholesterol, total bilirubin, albumin, total protein, urea, NEFA and BHBA. Milk production and body condition score were also estimated. Obtained results showed that cows were exposed to mild to marked metabolic distress. Energy status was changed due to increased values of NEFA and BHBA and decreased value of glucose after calving. Protein concentrations were increased at day 10 after calving, despite the decrease of the level of albumin. Urea concentrations before and after calving were within physiological range indicating an optimal protein diet. Increased values of total bilirubin at day 5 after calving indicated liver increased activity. Lipid status presented by triglycerides and total cholesterol revealed no differences in blood concentrations. Milk production was highest at day 30 after calving. BCS were highest in dry cows, thereafter they declined and recovered at day 60 after calving.

In conclusion, biochemical parameters can be used as relevant indicators of metabolic distress in cows around calving with milk and BCS recording as aside parameters. Changes in some biochemical parameters indicate liver increased activity and metabolic stress, that could lead to decreased milk production, impaired reproductive performance and, finally, to illness.

Open access
Quality Potential Of Some New Pear Cultivars – How To Obtain Fruit Of The Best Sensory Characteristics?

Abstract

The eating quality of nine new pear cultivars grown in Poland was investigated in 2008-2011. Fruits of two summer cultivars: ‘Alfa’ and ‘Radana’, as well as late season varieties: ‘Hortensia’, ‘Dicolor’, ‘Concorde’, ‘Uta’, ‘Xenia’, ‘Erika’ and ‘Verdi’ were compared to fruits of ‘Clapp’s Favorite’ and ‘Conference’, which were taken as cultivars of reference. Fruits of all cultivars were harvested from the Experimental Orchard of the Research Institute of Horticulture at the commercial maturity stage and stored at +2.5 °C or -0.5 °C in a normal atmosphere (NA) or at -0.5 °C in a controlled atmosphere (CA) (0.7% CO2 : 2% O2) for 6 to 16 weeks. At the end of storage, the fruits of each cultivar were subjected to an individual ripening schedule at 18 °C (up to 14 days), which generated samples of diversified quality attributes. Based on instrumental analyses and descriptive sensory assessment the quality attributes of each cultivar were examined. The gathered data on the dynamics of quality attribute changes during the ripening stage confirm that each new cultivar needs an individual strategy during storage and ripening in order to maximise their specific sensory attributes to increase potential market value. The obtained data leads to the conclusion that ‘Xenia’ and ‘Concorde’ fruits have the biggest chance to fulfil consumer expectations, as they were appreciated more than the reference ‘Conference’ cultivar. Among the others also ‘Hortensia’, ‘Verdi’ and ‘Dicolor’ were scored higher than ‘Conference’, but their advantages were not so evident.

Open access
Genomic Profiling of F1 Hybrids of Durian (Durio zibethinus ) Revealed by RAPD-PCR

Abstract

The molecular analysis of 32 durian F1 hybrids, resulted from crossing of the Arp 8990 (female parent) and ‘Otong’ (male parent), was conducted in order to determine the genetic characteristics of hybrids and parents, as it would be followed/evidenced by the variability of traits produced from the cross breeding. The RAPD analyses of 14 primers resulted in 114 scoring bands, 112 (98.2%) of them were polymorphic, with 4 to 11 bands amplified per primer. The electrophoresis gel of the PCR results revealed that some hybrids produced different band patterns compared to the parents; this indicated the crossing between parents’ alleles and trait combinations from both the parents. The Dice-Sorensen similarity coefficient demonstrated that most of the hybrids had distant genetic similarities with both parents, which were ranged from 0.141 [71B(4) and 72B(15)] to 0.776 [71B(15) and 48B(1)]. The UPGMA method was used to construct the dendrogram, which grouped the hybrids in five clusters with distinct genetic relationships and was confirmed with the PCA analysis. This result implied that above crossing produced hybrids having characters different from the parents.

Open access
Pattern Recognition of Tobacco Headspace GC Profiles: A Potential New Analytical Tool for the Classification of Raw Tobaccos

Abstract

The first part of the paper describes a new method of obtaining reproducible and meaningful headspace profiles of tobacco lamina by using a modified closed loop stripping apparatus. The complex chromatograms are obtained by high-resolution glass capillary gas chromatography. The second part summarizes the results of a chemometric approach to interpret the chromatograms obtained from a series of nine Virginia flue-cured tobaccos from different origins and belonging to different quality groups, each one analysed three times by the method described above. After the elimination of peaks containing redundant information, the resulting data set, consisting of 27 × 17 data points, was analysed to detect natural groupings by using an in-house program (in Basic) for principal component analysis. A subsequent discriminant analysis yielded two discriminant functions capable of separating the nine Virginia tobaccos into three quality groups as defined by a conventional organoleptic analysis carried out by a smoking panel. All the tobaccos could be classified correctly (100 %). A first attempt to classify, by the procedure described above, a group of six Virginia tobaccos whose organoleptic scores were not known, did not yield clearly interpretable results, possibly because the performance of the capillary column used for analysis had slightly deteriorated during the experiment with resultant changes in retention characteristics, which led to wrong identifications of certain peaks.

Open access
Influence Of Iron Sources In The Nutrient Medium On In Vitro Shoot Multiplication And Rooting Of Magnolia And Cherry Plum

Abstract

In this study, the effects of compounds providing Fe in chelated (NaFeEDTA and Fe(III)AC) and non-chelated (FeSO4·7H2O) forms as components of culture media, on in vitro shoot multiplication and rooting of Magnolia soulangeana ‘Alexandrina’, Magnolia grandiflora and Prunus cerasifera ‘Nigra’ were comparatively evaluated. Each of the tested chemicals was used as a single Fe source in the basal salt medium. In the stages of shoot multiplication and rooting plant response was scored by biometrical indices (number of shoots, leaves and roots, shoot and root length, percent of rooted plants and root hairs). The occurrence of physiological disorders was estimated by visual observations. In presence of FeSO4, symptoms of chlorosis, hyperhy-dricity, early senescence and specific morphology of roots, suggesting Fe deficiency, were observed. These deteriorations were entirely prevented at the application of Fe chelates of which, in this experimental systems, Fe(III)AC was tested for the first time. The addition of Fe(III)AC positively affected the plant quality to extent comparable to that of NaFeEDTA. The obtained data suggest that both applied Fe chelates are more appropriate than non-chelated Fe form and can be alternatively used in the optimization of nutrient media for micropropagation of Magnolia and Prunus cerasifera genotypes.

Open access
Control of Residues of Five Macrocyclic Lactones in Cow Milk By Liquid Chromatography with Fluorescence Detection

Abstract

A sensitive and reliable method has been developed and validated to determine residues of abamectin, doramectin, eprinomectin, ivermectin, and moxidectin in bovine milk. Isolation of the analytes from milk was performed with the use of liquidliquid extraction with acetonitrile in the presence of sodium chloride. The extract was defatted with hexane and cleaned up using solid phase extraction (C8 cartridge) after forming ion pairs with triethylamine. The analytes were derivatized with N, Ndimethylformamide, acetic acid anhydride, and N-methylimidazole (100°C, 90 min). The derivatives were determined by reverse phase liquid chromatography with fluorescence detection (excitation and emission wavelength 365 nm and 475 nm, respectively). Recoveries of the lactones from milk samples fortified at 10-30 μg kg-1 ranged from 52% to 80% with intra-laboratory reproducibility (CV) of 12.7%-22.8%. The critical concentrations (decision limit, CCα and detection capability, CCβ) were in accordance with target limits. The method has been verified in the proficiency studies by EURL/CVL Berlin (all z-scores in the range of ±2). The method was transferred to routine laboratories, verified in inter-laboratory comparison and successfully applied in the National Residue Control Plan.

Open access