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Open access

Ewelina Patyra, Ewelina Kowalczyk and Krzysztof Kwiatek

Abstract

A chromatographic procedure for determination of oxytetracycline (OXT), tetracycline (TC), chlorotetracycline (CTC), and doxycycline (DC) in water samples was developed and was applied for the analysis of water samples collected from poultry and pig farms and environmental water samples. Samples were acidified with trifluoroacetetic acid to pH 3 and further purified by solid phase extraction using Oasis HLB cartridges. The samples were dried up and redissolved in the mixture of oxalic acid and methanol. Separation was performed on reserved phase column (Phenomenex column C18 , 250 mm × 4.6 mm, 5 μm) by multistep gradient elution, and detection was carried out at 360 nm for OTC and TC, 370 nm for CTC, and 350 nm for DC. The tetracyclines were eluted with the mobile phase of 0.05 M oxalic acid (pH 2.5), acetonitrile, and methanol. This method provided average recoveries of 83.53% to 108.59%, with coefficient of variations (CVs) of 2.41% to 8.64% in the range of 10 to 1000 μg/L OTC, TC, CTC, and DC in water. The linearity for the tetracyclines was determined by HPLC-DAD in the range 10 to 1000 μg/L, with the correlation coefficient (R) > 0.99. The LOD and LOQ for the tetracyclines in water samples ranged from 1.51 to 4.00 and 2.51 to 5.93 μg/L, respectively.

Open access

Marzena Pawul-Gruba, Mirosław Michalski and Jacek Osek

Abstract

The high performance liquid chromatography with diode array detection was used for the study. The histamine was detected in 14.6% and 17.8% of the samples of fresh and smoked fish respectively. The highest concentrations of the compound were found in smoked herring and smoked sprat (17.7 mg/kg and 24.1 mg/kg respectively). Histamine concentration in fresh and smoked fish did not exceed the allowable limit, indicating that they are safe for consumers.

Open access

Agnieszka Kosińska, Anna Urbalewicz, Kamila Penkacik, Magdalena Karamać and Ryszard Amarowicz

SE-HPLC-DAD Analysis of Flaxseed Lignan Macromolecule and its Hydrolysates

A lignan macromolecule (LM) was extracted from defatted flaxseeds using an ethanol-dioxan system (1:1, v/v) and purified using Amberlite column chromatography with water and methanol as mobile phases. The LM was subjected to chemical hydrolysis (base, acid, base & acid), as well as to enzymatic processing using pepsin, pancreatin, cellulase, and β-glucuronidase.

The study revealed that lignan macromolecule in flaxseed was not homogenous. The chemical hydrolysis as well as enzymatic treatment using β-glucuronidase and cellulase released low molecular phenolic compounds from the lignan macromolecule. The liberation of secoisolariciresinol (SECO) and free phenolic acids (p-coumaric and ferulic acids) from flaxseed lignan macromolecule as a result of the base and acid hydrolyses was noted. The application of pepsin and pancreatin did not change the composition of the lignan macromolecule.

Open access

Bisera Janeska, Marina Stefova and Kalina Alipieva

Assay of flavonoid aglycones from the species of genus Sideritis (Lamiaceae) from Macedonia with HPLC-UV DAD

Flavonoids obtained from Sideritis species (Lamiaceae), S. raeseri and S. scardica, grown in Macedonia were studied. Qualitative and quantitative analyses of the flavonoid aglycones were performed using high-performance liquid chromatography (HPLC) with a UV diode array detector. Extracts were prepared by acid hydrolysis in acetone, re-extraction in ethyl acetate and evaporation to dryness; the residue dissolved in methanol was subjected to HPLC analysis.

Isoscutellarein, chryseriol and apigenin were identified in the extracts. Also, a 4'-methyl ether derivative of isoscutellarein was found, together with hypolaetin and its methyl ether derivative, which were identified according to previously isolated glycosides and literature data. Quantitation was performed using calibration with apigenin.

According to this screening analysis, the samples of the genus Sideritis from Macedonia are rich in polyhydroxy flavones and analogous with the previously studied Mediterranean Sideritis species from the Ibero-North African and Greek Sideritis species with respect to the presence of 8-OH flavones and their derivatives.

Open access

R.V. Filimon, D. Beceanu, M. Niculaua2 and Cristina Arion

ABSTRACT -

The purpose of this study is to evaluate the anthocyanin (AC) and phenolic compounds (TPC) content, and the description of anthocyanin profile obtained by HPLC-DAD technique (High- Performance Liquid Chromatography - Diode Array Detector), from hydroalcoholic extracts of four varieties of sour cherry (Prunus cerasus L.) grown in experimental field of Research-Development Station for Fruit growing Iași, Miroslava area. Were also examined some physical-chemical properties of fruits, variety Mocăneşti 16 showing the highest moisture content (87.98%), titratable acidity (1.32 g malic/100g acid) and ascorbic acid (12 mg / 100g). AC, determined by pH differential method, had the highest value at Engleze timpurii variety (176.2 ± 0.97 mg/100g) and TPC, determined by the Folin-Ciocâlteu colorimetric method, had the maximum value at Mocăneşti 16 variety (446.89 ± 0.70 mg GAE/100g). Based on the chromatograms obtained, were identified four anthocyanins: cyanidin (cy)-3- glucoside, cy-3-rutinoside, cy-3- sophoroside, cy-3-glucosylrutinoside, expressed as a percentage of anthocyanins area. Anthocyanin profile obtained was not similar in varieties examined, and the ratio between anthocyanins differed from one variety to another. The data obtained confirm previous results on the sour cherries anthocyanin profile and can be used in food and pharmaceutical industry (functional foods) and as a basis of comparison for future studies.

Open access

Anneli Salonen, Sanna Saarnio and Riitta Julkunen-Tiitto

Phenolic Compounds of Propolis from the Boreal Coniferous Zone

The profile of phenolic compounds in 19 propolis samples from different provinces in Finland were analysed for the first time using HPLC-DAD. Nine individual flavonoids (comprising 26% of the identified phenolics), eleven cinnamic acid derivatives (36%), two caffeic acid derivatives (14%), three chlorogenic acid derivatives (14%), and three other phenolic acids (10%) were found in the propolis samples. The compounds found in the largest quantities were methyl-naringenin and caffeic acid phenethyl ester (CAPE). The phenolic profiles of Finnish propolis show marked differences when compared with P. nigra and P. tremuloides propolis of Central European and Canadian origins. The phenolic compounds found in propolis samples are commonly found in the tree species growing in Finland. Non-metric multidimensional scaling showed that samples were scattered and they did not form clear groups according to the geographical origin or age of the sample.

Open access

Anna Madejska, Mirosław Michalski, Marzena Pawul-Gruba and Jacek Osek

Abstract

Introduction: In recent years, there has been a great interest in biogenic amines such histamine, as they are associated with the quality and safety of some kinds of fermented foods. The aim of this study was to evaluate the effect of temperature and storage time on the content of histamine in cheeses.

Material and Methods: Samples of mould and hard cheeses were examined with RP-HPLC with an organic-aqueous mobile phase containing acidic buffer and chaotropic salt. The samples were stored either at 22 ± 2°C for 42 days (mould and hard cheeses) or at 4 ± 2°C for 112 days (mould cheeses) and 133 days (hard cheeses).

Results: The mean total histamine content in cheeses stored at 22°C was higher than the content in those stored at 4°C, with the highest concentrations found in Gorgonzola Piccante cheese (730.47 mg/kg). Histamine concentration in some types of cheeses exceeded the toxic threshold dose, indicating that after long or inadequately cool storage they may not be safe for consumers.

Conclusion: To protect cheeses from contamination with histamine-producing bacteria and to safeguard consumers from poisoning, factors conducive to this amine’s formation should be minimised during cheese processing. Suitable temperature and time during storage of cheeses are recommended to avoid the intoxication. Monitoring of this toxin in food is necessary to ensure safety of consumers.

Open access

Jianping Chen, Zhonggui Li, Ken Y. Z. Zheng, Ava J. Y. Guo, Kevin Y. Zhu, Wendy L. Zhang, Janis Y. X. Zhan, Tina T. X. Dong, Ziren Su and Karl W. K. Tsim

Abstract

Gleditsiae Fructus Abnormalis and Gleditsiae Sinensis Fructus are obtained from different developmental stages of fruits from Gleditsia sinensis Lam. (Leguminosae). The possible interchangeable usage of the two fruits, however, has long been very controversial. Here, high performance liquid chromatography coupled with diode array detection was developed to explore their chemical fingerprinting profiles. Besides, the amounts of aglycones of saponin compounds, echinocystic acid and oleanolic acid in both fruits were quantified. The results indicated that there was no significant difference in the content of aglycones from the two types of fruits. However, their chromatographic fingerprints showed distinct characteristics. Therefore, the interchangeable application of these fruits has to be taken with a specific precaution.

Open access

F. Malhat, H. Watanabe and A. Youssef

Summary

A high performance liquid chromatography with the photodiode array detector (HPLCDAD) analytical method was developed to determine the residue levels and investigate the dissipation pattern and safety use of methomyl in tomato and soil. Methomyl residues were extracted from tomato and soil samples with ethyl acetate. The extract was cleaned up with the QuEChERS method. The results showed that the average recoveries were in the range of 87.1-94.5%, with RSD of 6.9-11.2%. Limits of detection (LOD) and quantification (LOQ) were 0.005 and 0.007 mg/kg, respectively. The residue levels of methomyl were best described to first order rate kinetics and half-lives ranged from 1.34 to 1.8 days in tomato and soil, respectively. The theoretical maximum residue contributions for methomyl on tomato were found to be less than the maximum permissible intake values even on zero days, therefore consumer health risks are minimal at the recommended dose on tomato.

Open access

Ewa Waś, Teresa Szczęsna, Helena Rybak-Chmielewska, Dariusz Teper and Katarzyna Jaśkiewicz

Abstract

A method was elaborated to determine phenolic compounds (vanillin, caffeic, p-coumaric and salicylic acids, and flavonoids: rutin, hesperetin, quercetin, pinocembrin, apigenin, kaempferol, isorhamnetin, chrysin, and acacetin) in bee pollen loads using highperformance liquid chromatography with a diode array detector (HPLC-DAD). Phenolic compounds from bee pollen were isolated on Cleanert C18-SPE columns (500 mg/6 mL, Agela Technologies). Polyphenols were identified by comparing the retention times and spectra of compounds found in pollen load samples with the ones of the standard mixture. Quantitative analysis was conducted using the external standard method. In addition, basic validation parameters for the method were determined. For the identified compounds (except for the salicylic acid), satisfactory (≥0.997) linear correlations were obtained. The elaborated method showed high repeatability and inter-laboratory reproducibility. Variability coeffcients of the majority of phenolic compounds did not exceed 10% in conditions of repeatability and inter-laboratory reproducibility, and for the total polyphenolic content they were 1.7 and 5.1%, respectively. The pollen load samples (n = 15) differed in qualitative and quantitative composition of the phenolic compounds. In all the samples, we identified the p-coumaric and salicylic acids and flavonoids rutin, hesperetin, and apigenin nevertheless, these compounds’ contents significantly differed among individual samples. The total phenolic content in the tested samples of pollen loads ranged from 0.653 to 5.966 mg/100 g (on average 2.737 mg/100 g).