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1

Characteristics of acid phosphatase from rainbow trout (Oncorhynchus mykiss) spermatozoa

100%
Sarosiek B., Wysocka J., Wysocki P., Glogowski J.
Archives of Polish Fisheries
|
2005
|
tom 13
|
nr 2
Acid phosphatase (AcP) is a commonly observed enzyme in animal semen. In this study, AcP in rainbow trout (Oncorhynchus mykiss) spermatozoa was partly purified and characterized. Extraction in 0.85% NaCl with 0.1% Triton X-100 enabled obtaining 95% of total AcP activity observed in sperm supernatant. Kinetic characteristics were described for the enzyme from sperm extract and for the partly purified enzyme following gel filtration. The optimum pH was 5.8 for unpurified and 5.6 for partly purified enzyme. The affinity of the substrates measured in the sperm extract for p-nitrophenylphosphate dissodium salt and b-glycerophosphate was Km = 1.5 × 10-3M and Km = 1.9 × 10-3M, respectively. The Km for partly purified enzyme was similar at 1.67 × 10-3M measured with p-nitrophenylphosphate dissodium salt. L-tartaric acid and ammonium molybdate were the inhibitors of AcP for unpurified and partly purified enzyme. SDS-PAGE electrophoresis revealed that AcP from rainbow trout had a molecular weight of about 41 kDa.
2

Analytical pocedure for the determination of lincomycin in honey by liquid chromatography-mass spectrometry

100%
Bladek T., Gajda A., Gbylik M., Posyniak A., Zmudzki J.
Bulletin of the Veterinary Institute in Puławy
|
2010
|
tom 54
|
nr 2
205-209
A reliable and sensitive liquid chromatography-electrospray ionisation tandem mass spectrometry analytical method has been developed for the determination of lincomycin in honey samples. After extraction with phosphate buffer by ultrasound, the extracted solution was subjected to the polymeric solid-phase extraction cartridge to remove endogenous compounds. The analysis was carried out on a triple-quadropule tandem mass spectrometer in the multiple reaction monitoring (MRM) mode via electrospray interface operated in positive ionisation modes. The procedure was validated in accordance with the European Commission Decision 2002/657/EC. The mean recovery of the analyte was 80%, with the corresponding intra- and inter-day variation less than 10% and 15%, respectively. Decision limits (CCα) and detection capability (CCß) were 5.60 and 6.11 µg kg⁻¹, respectively.
3

ICP-OES determination of select metals in surface water - a metrological study

100%
Chochorek A., Bobrowski A., Kiralyova Z., Mocak J.
Polish Journal of Environmental Studies
|
2010
|
tom 19
|
nr 1
59-64
Ten selected metals, namely Zn, Cr, Cd, Cu, Ni, Pb, Fe, Mn, Mg and Ca, commonly present in surface waters were determined by inductively coupled plasma atomic emission spectroscopy (ICP-OES). For all quantitative analyses, basic metrological characteristics were obtained, including estimation of combined and expanded uncertainties. Special attention was given to ascertaining which component of uncertainty plays a dominant role in the overall determination process (from sampling to final results), and particularly, in ICPOES calibration and measurement. The largest contribution to the combined uncertainty of the final analytical determination of the element concentrations was due to sampling and calibration, as well as general imprecision of the whole analytical procedure.
4

Validation of an analytical procedure for selected polychlorinated biphenyls determination in sediment samples

100%
Szyrwinska K., Lulek J.
Polish Journal of Environmental Studies
|
2006
|
tom 15
|
nr 4
This paper describes the method for determining 15 individual polychlorinated biphenyls in sediments, using fexIKA extraction. The analytical procedure included extraction and clean-up of extracts with con­centrated sulfuric acid and solid phase extraction (SPE) on Florisil. The identification and quantification of analytes were carried out by capillary gas chromatography (GC) with electron capture detector (ECD) and/or low resolution mass spectrometry (LRMS). The method detection and quantification limits varied from 0.06 to 0.12 and from 0.2 to 0.4 ng/g dry weight, respectively. The relative standard deviations in repeatability and intra-laboratory reproducibility studies varied from 3.2 to 11.2%. Recoveries of analytes from spiked sediment samples were between 74.0% and 108.8%. The method was linear and characterized by good correlation coefficients (>0.99) for all compounds studied. The quality of the method under valida­tion was verified by the analysis of certified reference material and by participation in an interlaboratory exercise.
5

Determination of thiamine in premixture and compound feed by liquid chromatography method

100%
Rubaj J., Korol W., Bielecka G., Kwiatek K.
Bulletin of the Veterinary Institute in Puławy
|
2008
|
tom 52
|
nr 3
The analytical procedure of thiamine quantification in premixtures and compound feedingstuffs by HPLC method is presented. Thiamine was extracted from feed samples with 0.1M hydrochloric acid at 100°C for 30 min. In the case of compound feedingstuffs, 10% Taka-diastase solution was added to the samples, and then the samples were incubated at 37°C for 17 h. Afterwards, thiamine was oxidised to thiochrom, using 1% alkaline potassium ferricyanide (III). The filtrated solution was analysed by HPLC with isocratic flow of eluent chloroform-methanol 90:10 (v/v). The measurement was done by a fluorescence detector. This method has been applied for the quantification of the total content of thiamine in compound feedingstuffs, as well as added thiamine in the form of hydrochloride or nitrate salt. The limit of the quantification of this method was determined on the level of 1 mg/kg. The coefficient variation of thiamine quantification results in premixţures samples was 3.7%, and in compound feedingstuffs was 5.56%. The Horrat value for premixture samples reached a value of 0.60, whereas in the case of compound feedingstuffs it was 0.63, thus confirming acceptable precision of the procedure. The recovery rate for thiamine added in the form of hydrochloride was 102.3% in premixes and 98.9% in compound feedingstuffs. The recovery rate for thiamine added in the form of nitrate salt to compound feedingstuffs was similar and reached a value equal to 98.7%.
6

Analytical procedure for the determination of doxycycline residues in animal tissues by liquid chromatography

100%
Gajda A., Posyniak A., Pietruszka K.
Bulletin of the Veterinary Institute in Puławy
|
2008
|
tom 52
|
nr 3
A sensitive liquid chromatographic method for the determination of doxycycline in animal tissues has been prepared and validated. The extraction of the analyte from biological matrix was performed with the solution of oxalic acid and ethyl acetate. The samples were cleaned up by solid phase extraction (SPE) procedure using a carboxylic acid cartridge. Chromatographic separation was carried out on the C8 analytical column and the mobile phase consisting of acetonitryle-methanol-0.02 M oxalic acid (20:15:65, v/v/v), with the detection by UV detector at λ = 355 nm. This method has been successfully validated and used for the quantitative determination of doxycycline in animal tissues samples. Recoveries from spiked samples were from 65% to 90%. The decision limits (CCα) were 110 µg/kg and 610 µg/kg for muscles and kidneys, respectively.
7

Evaluation of some immunoregulatory cytokines in serum of rats exposed to cadmium and ethanol

84%
Moniuszko-Jakoniuk J., Jurczuk M., Galazyn-Sidorczuk M.
Polish Journal of Environmental Studies
|
2009
|
tom 18
|
nr 4
673-680
The aim of the present study was to investigate the effects of cadmium (Cd) (5 and 50 mg Cd/l in drinking water) and ethyl alcohol (ethanol, EtOH) (5 g EtOH/kg b.wt., intragastrically), administered alone or simultaneously, on the concentrations of pro-inflammatory (interleukin-1, IL-1?; interleukin-6, IL-6; tumor necrosis factor-?, TNF? and interferon ?, INF?) and anti-inflammatory (interleukin-4, IL-4) cytokines in the serum of rats. In order to estimate the involvement of Cd- or/and EtOH-induced oxidative stress in damage to cytokines, the concentration of protein carbonyl groups (PC), as a marker of oxidative protein damage, was also determined. Exposure to 5 and 50 mg Cd/l, alone or in combination with EtOH, led to an increase in the serum concentrations of IL-1?, TNF? and INF? with a simultaneous decrease in IL-4 concentration, compared to the control. The concentration of IL-6 was elevated only after administration of 50 mg Cd/l, both alone and in combination with EtOH. The exposure to EtOH alone resulted in increased concentrations of TNF? and INF?, as well as in decreased concentrations of IL-4. In rats co-exposed to Cd and EtOH, the changes observed in the concentrations of the cytokines, except in IL-6, were more advanced, compared to the animals treated with these xenobiotics alone. Exposure to Cd and EtOH, both alone and in combination, caused an increase in the serum PC concentration. The concentration of PC positively correlated with the concentrations of IL-1?, IL- 6, TNF? and INF? and negatively with IL-4 concentration. The results suggest that changes in the cytokines examined are more enhanced after combined exposure to Cd and EtOH, especially at higher Cd dosage. Moreover, it can be hypothesized that oxidative stress may be involved in the mechanism leading to changes in the concentration of cytokines after exposure to Cd and EtOH alone and in combination.
8
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Optimisation and validation of the analytical procedure for the determination of acrylamide in coffee by LC-MS/MS with SPE clean up

84%
Gielecinska I., Mojska H.
Roczniki Państwowego Zakładu Higieny
|
2013
|
tom 64
|
nr 2
Background. Numerous studies have demonstrated acrylamide to be both neurotoxic and carcinogenic. At present it is widely recognised that acrylamide is mainly formed through the Maillard reaction from free asparagine and reducing sugars. The major sources of dietary acrylamide are potato products, processed cereals and coffee. Objective. To optimise and validate an analytical method for determining acrylamide in coffee by liquid chromatography and tandem mass spectrometry analysis (LC/MS/MS) using SPE clean-up. Material and methods. Analytical separation of acrylamide from roasted coffee was performed by liquid chromatography using a Hypercarb column followed by LC/MS/MS analysis, with 2,3,3–d3 acrylamide as an internal standard. The method was based on two purification steps: the first with hexane and Carrez solutions in order to remove of fat and to precipitate proteins, respectively; and the second with a solid-phase extraction (SPE) column which proved to be efficient in the elimination of the main chromatographic interferences. Results. Limit of quantification (LOQ) for measuring acrylamide in coffee was 50 μg/kg. The described method demonstrates satisfactory precision (RSD = 2.5%), repeatability (RSD = 9.2%) and accuracy (mean recovery – 97.4%). Conclusions. Our results confirm that LC-MS/MS with SPE clean-up is selective and suitable for determination of acrylamide in coffee. Indeed, this method meets the criteria of EU Commission Recommendations (No. 2007/331/EC and No. 2010/307/EU), on the monitoring of acrylamide levels in food.
9

Analytical procedure for the determination of fluoroquinolones in animal muscle

84%
Posyniak A., Mitrowska K.
Bulletin of the Veterinary Institute in Puławy
|
2008
|
tom 52
|
nr 3
A liquid chromatography-fluorescence detection method for the determination of five fluoroquinolones in muscle tissue was proposed. The method is selective and robust enough for the required purposes. The whole procedure was validated in accordance with the Commission Decision 657/2002/EC. Detection capabilities were from 132.8 to 421.0 µg/kg, and recoveries ranged from 51.7% to 80.91%, depending on the analyte.
10

Improved analytical procedure for the determination of sulfonamides in honey

84%
Posyniak A., Jazdzewski K., Pietruszka K., Mitrowska K., Gajda A.
Bulletin of the Veterinary Institute in Puławy
|
2008
|
tom 52
|
nr 1
An improved liquid chromatography-fluorescence detection method for the determination of seven sulfonamides in bee honey was proposed. The method is selective and robust enough for the required purposes. The whole procedure was validated in accordance with the Commission Decision 657/2002/EC. Detection capabilities were from 26.15 to 49.50 µg/kg, and recoveries ranged from 32.8% to 116.1%, depending on the analyte.
11

Relationship between citric acid production and accumulation of phytate-degrading enzymes in Aspergillus niger mycelia

67%
Kujawski M., Zyla K.
Acta Microbiologica Polonica
|
1992
|
tom 41
|
nr 3-4
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