Corn, wheat and other different types of cereal crops, are one of the basic nutritional products in general, which have essential and vast application in the daily diet of people around the world. ...Cereal crops are the most important food sources, and cereal-based food is the main source of energy, protein, B vitamins and minerals for the world population. Therefore, the goal of this research is to analyze the production of wheat on arable land in the Republic of North Macedonia, as an agricultural country, which will indirectly help to draw conclusions about the impact on the economic structure of the population, their standard of living, the investment and economic fluctuations in market prices, taken as a sui generis element, set as an assumption ceteris paribus against the other determinants and factors that affect the national economy in the Republic of North Macedonia.
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β-lactamases are a diverse class of enzymes produced by bacteria that present a major cause for resistance to β-lactams. In this study we analysed 159 fecal samples from dairy cows, for the presence ...of presumptive ESBL, AmpC, and carbapenemase-producing
. Phylotyping was done using Clermont phylo-typing method, targeting arpA, ChuA, and YjaA genes, along with the DNA fragment TspE4.C2. Convetional PCR method was used to confirm the presence of
genes among 39 phenotypically confirmed ESBL producing
The results showed presence of CTX-M, SHV, TEM and OXA1
genes in 28 (71.79%), 1 (2.56%), 29 (74.35%), 2 (5.12%) of isolates, respectively Twenty (51.28%) isolates showed presence of both
CTX-M and TEM genes. The strain that carried the
SHV gene was found to carry
TEM gene as well, while one of the strains that carried
OXA1 gene was also carrying
CTX-M and TEM gene. The ration between isolates and phylo-groups was as follows: 9 (23.07%) strains were assigned to phyllo-group D; 14 (35.89%) to phyllo-group B; 16 (41.02%) to phyllo-group A. Out of the 39 strains where
genes were identified, 29 (74.35%) were categorized as multi drug resistant.
Wheat is one of the world’s most commonly consumed cereal grains. It originates from a type of grass (Triticum) that is grown in countless varieties worldwide. Bread wheat or common wheat is a ...primary species. Several other closely related species include durum, spelt, emmer, einkorn, and Khorasan wheat. In addition to being a major source of starch and energy, wheat also provides substantial amounts of a number of components which are essential or beneficial for health, notably proteins, vitamins (notably B vitamins), dietary fibres, and phytochemicals. Wheat is a basic food product of Macedonian population. This study is mainly focused on measuring the concentration of radioactivity due to natural radioactive nuclides (226Ra, 232Th, 40K) in wheat grain samples, as well as on determining the quality of wheat used in daily diet. In addition, in this study we calculated radiation hazard indices (radium equivalent activity and internal hazard index) in the wheat sample. Average activity concentrations of 226Ra, 232Th, and 40K in the wheat samples were 0.57±0.14; 0.39±0.11; 96.55±0.86 (Bq·kg-1), respectively. The radiation hazard indices were calculated for all samples in this study where mean values did not exceed safety limits, pointing out to negligible radiation hazard arising from terrestrial radionuclides that are naturally present in wheat. In terms of quality, we confirmed that all tested samples meet the requirements regarding quality in accordance with the laws in our country.
Abstract
Background
Veterinary drugs are widely used in animals to prevent diseases and are a complex set of drugs with very different chemical properties. Multiclass and multi-residue methods for ...simultaneous detection of residues from veterinary drugs and contaminants in urine are very rare or non-existent. Therefore, the aim of this study was to develop and validate a sensitive and reliable quantitative LC-MS/MS method for simultaneous determination of a wide range of veterinary drug and pesticide residues and mycotoxins in bovine urine. This involved 42 veterinary drug residues (4 thyreostats, 6 anabolic hormones, 2 lactones, 10 beta agonists, 15 antibiotics, 5 sulphonamides), 28 pesticides and 2 mycotoxins. Stable isotopically labelled internal standards were used to facilitate effective quantification of the analytes. Analysis was performed in both positive and negative ionization modes with multiple reaction monitoring transitions over a period of 12 min.
Results
The parameters validated included linearity, limit of detection (LOD), limit of quantification (LOQ), detection capability (CCβ), decision limit (CCα), stability, accuracy and precision. The process followed guidelines of the regulation 2021/808/EC. The calibration curves were linear with coefficient of correlation (R
2
) from 0.991 to 0.999. The LODs were from 0.01 to 2.71 µg/L, while the LOQs were from 0.05 to 7.52 µg/L. The CCα and CCβ were in range 0.05–12.11 µg/L and 0.08–15.16 µg/L. In addition, the average recoveries of the spiked urine samples were from 71.0 to 117.0% and coefficient of variation (CV) < 21.38% (intraday and interday).
Conclusion
A new isotopic LC-MS/MS method has been developed, validated and applied for identification and quantification of 72 residues of veterinary drugs and pesticides and other contaminants such as mycotoxins in bovine urine. The most appropriated sample preparation procedures involved sodium acetate buffer, enzymatic hydrolysis using β-glucuronidase and cleanup solid phase extraction with OASIS SPE cartridges. The parameters were satisfactorily validated fulfilling requirements under Regulation 2021/808/EC. Consequently, the method could be used in routine analysis of bovine urine samples for simultaneous detection of veterinary drug and pesticide residues as well as contaminants such as mycotoxins.
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Analytical methods based on immunoaffinity column clean-up and quantitative determination with liquid chromatography-fluorescence detection were used to determine aflatoxins and ochratoxin A in liver ...samples. The validation of the procedures was performed. The linearity of the methods was checked, and a good coefficient of correlation was found for all aflatoxins and OTA as well. The LOD and LOQ were acceptable: 0.003 µg/kg and 0.009 µg/kg for AFB
; 0.001 µg/kg and 0.005 µg/kg for AFB
; 0.006 µg/kg and 0.020 µg/kg for AFG
; 0.007 µg/kg and 0.022 µg/kg for AFG
; 0.08 µg/kg and 0.27 µg/kg for OTA. The results for the repeatability estimated by the relative standard deviation (RSD
) were satisfactory and the obtained values were in the acceptable range (1.97–14.41% for all aflatoxins and 3.76-8.31% for OTA) at three proposed concentration levels. RSD
values showed acceptable correlation between two analysts for all four aflatoxins and OTA. The RSD
values were as followed: 2.37% and 5.60% for AFB1, 6.71% and 8.78% for AFB
, 4.40% and 7.00% for AFG
and 10.30% and 13.91% for AFG
(for the first and second analyst, respectively). The RSDR values for OTA were 4.91% and 3.15% (1 µg/kg); 3.76% and 4.12% (5 µg/kg) and 8.31% and 8.21% (10 µg/kg). The mean recovery for total aflatoxins and OTA were 78.10% and 93.34%, respectively. All validation parameters were in accordance to European legislation. They indicate that the proposed analytical procedures are suitable and they could be methods of choice for the determination of aflatoxins and OTA in liver samples.
Screening and confirmatory methods for Aflatoxin M1 (AFM1) analysis were optimized and studied regarding the European Decision 2002/657/EC requirements. The recoveries of AFM1 from the spiked samples ...at levels between 0.025 and 0.075 µg kg-1 were 99.6-110.3 % with obtained precision 10.5-13.4 %, confirming the immunochemical method precision and reliability for intensive surveillance studies. According to the regulatory requirements, for confirmation of the obtained positives from the screening, the reference high-performance liquid chromatographic method was evaluated in reference to the performance criteria. The obtained between-day recovery was in the range 67.2-72.8 %, and the precision range 5.4-9.1 %. 205 positives from the screening were subjected to confirmatory analysis. The comparison of the data obtained from the immunoassay and chromatographic method (R2=0.764) revealed a slight overestimation of the screening method, but no cases of false-negative determinations occurred.
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A different, reliable, and cost-effective strategy for the analysis of aflatoxins, ochratoxin A, and zearalenone in corn-based foods was proposed, including one multi-toxin immunoaffinity column ...(IAC) sample preparation and three different high-performance liquid chromatography fluorescence detection methods. The analytical procedures were tested and verified, keeping in mind their occurrence at trace levels in corn-based foods. With the validation of the proposed multi-toxin IAC methodology and comparison of the performance characteristics with methods using a single-toxin IAC, we confirmed the reliability of the multi-toxin IAC procedure versus the single-toxin IAC. The methods were validated by revealing satisfactory performance characteristics; for example, the obtained values of limit of detection were significantly lower than the maximum limits for all mycotoxins of concern. In addition, the recovery values were between 70.9 % and 106.1 % for all mycotoxins of interest, with precision values lower than 10.5 %.
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The use of β-agonists in livestock production is prohibited in many countries because the residues of β-agonists in food pose a potential risk to human health. The present work describes the ...development and validation of the LC-MS/MS method for detection of ten β-agonists in bovine urine according to Commission Decision 2002/657/EC requirements. Linearity of the method resulted with coefficient of correlation >0.990. The decision limits (CCα) ranged from 0.127 ng/mL to 0.646 ng/mL, and the detection capability (CCβ) resulted in the range 0.140 ng/mL to 0.739 ng/mL. The observed recoveries in the fortified bovine urine samples were satisfactory at every fortification level with values from 73.67% to 118.80%. The coefficient of variation (CV, %) at three fortification levels for each β-agonist was in complete agreement with the requirements from Commission Decision 2002/657/EC. The CV for intraday precision varied from 1.619% to 15.472% and the CV for interday precision varied from 2.695% to 10.441%. From the obtained validation results the proposed method is an appropriate method for determination of β-agonists in bovine urine.
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Anabolic androgenic steroids are synthetic derivatives of testosterone, which is the primary male sex hormone. These anabolic agents are used to increase the weight gain, to improve the food ...efficiency, storing proteins and to decrease fatness. However, depending on the use of anabolic agent in animal feed, anabolic residues that may occur in meat and meat products present risks to human health. The aim of this study was the validation of screening ELISA method for determination of methyltestoterone anabolic steroid in fish. The validation process was carried out according to Commission Decision 2002/657/EC criteria. The detection limit for methyltestosterone was 140.95 ng/kg and the detection capability was 564.43 ng/kg. The overall recoveries and the coefficients of variation (CV) were in the range of 82.4%-97.4% and 1.5%-6.9%, respectively, a working range between 50 to 4050 ng/kg, and the regression equation of the final inhibition curve was: y= -0,1741x + 1,5082, R2 = 0.9927. Because of the good recovery and precision, and satisfactory detection capability, this method is applicable in official control laboratories as a rapid screening method for determination of methyltestosterone in fish.
A different, reliable, and cost-effective strategy for the analysis of aflatoxins, ochratoxin A, and zearalenone in corn-based foods was proposed, including one multi-toxin immunoaffinity column ...(IAC) sample preparation and three different high-performance liquid chromatography fluorescence detection methods. The analytical procedures were tested and verified, keeping in mind their occurrence at trace levels in corn-based foods. With the validation of the proposed multi-toxin IAC methodology and comparison of the performance characteristics with methods using a single-toxin IAC, we confirmed the reliability of the multi-toxin IAC procedure versus the single-toxin IAC. The methods were validated by revealing satisfactory performance characteristics; for example, the obtained values of limit of detection were significantly lower than the maximum limits for all mycotoxins of concern. In addition, the recovery values were between 70.9 % and 106.1 % for all mycotoxins of interest, with precision values lower than 10.5 %.
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