Amines In Samples Research Articles

Evaluation of Nitrite, Ethyl Carbamate, and Biogenic Amines in Four Types of Fermented Vegetables.

Nitrite, ethyl carbamate, and biogenic amines in fermented vegetables are considered harmful compounds. In this study, the concentration of the nitrite, ethyl carbamate, and biogenic amines in four different varieties of fermented vegetables in China was determined. The results show that the nitrite concentration in the fermented cabbage was the highest, followed by fermented mustard, fermented bamboo, and fermented radish. Additionally, nitrite concentration in two fermented cabbage samples and one fermented mustard sample exceeded the maximum allowed residue limit (20 mg/kg) suggested by China’s National Food Safety Standards. However, only one fermented cabbage sample had a very low level of ethyl carbamate (<10 μg/kg). Otherwise, higher biogenic amines were found in the samples of fermented cabbage, fermented bamboo, and fermented mustard. Additionally, the concentration of biogenic amines in some samples exceeded the recommended limit. On the contrary, biogenic amines in fermented radish samples were relatively low. Therefore, the concentration of nitrite and biogenic amine should be closely monitored and controlled during the vegetable fermentation processes, especially for the fermentation processes of bamboo, cabbage, and mustard.

Development of a SALLE-HPLC-FLD Analytical Method for the Simultaneous Determination of Ten Biogenic Amines in Cheese

In this work, a new methodology for the determination of biogenic amines in cheese is presented, which includes an innovative sample preparation approach based on salting-out assisted liquid-liquid extraction (SALLE). The method features a pre-extraction of the soluble biogenic amines with hydrochloric acid, a derivatization with dansyl chloride, the use of the salting-out effect, and the analysis of the derivatized biogenic amines using high-performance liquid chromatography with fluorescence detection. Several extraction parameters were studied and optimized, such as the HCl extraction time, concentration of the derivatization reagent and influence of the medium’s pH, among others. For the considered biogenic amines, the developed method exhibits adequate limits of detection (0.015 to 1.77 mg L−1) and quantification (0.050 to 5.91 mg L−1) and average recoveries between 94 and 110%, with the highest determined amounts found for putrescine, dimethylamine and histamine. Furthermore, mass spectrometry studies identified and confirmed the presence of several biogenic amines in the samples. SALLE stands as a good alternative to existing methods, since it simplifies the sample preparation step, while improving the overall selectivity of the process. It may also be adopted for the determination of biogenic amines in different solid samples besides cheese, such as meat, fish or other food products.

Biological amine (histamine and tyramine) content and its relationship with physical-chemical characteristics of chicha de jora samples prepared in the province of Abancay, Apurímac

Chicha de jora, being a spontaneous fermentation drink, does not offer information about the metabolites produced by the microorganisms responsible for fermentation, thus its innocuousness for consumers is unknown. Given this situation, the aim of this study was to determine the content of biogenic amines in samples from the province of Abancay (districts of Abancay and Tamburco) using HPLC, compare these values with the permissible limits and evaluate the biogenic amine content and physicochemical characteristics of “chicha de jora”. Of the 83 samples analyzed, concentrations of up to 37.53 mg/L of histamine and 77.95 mg/L of tyramine were reported. 7% and 12% of the samples from Abancay and Tamburco respectively reported concentrations above the permissible limit of histamine (8 mg/L); and 16% of the samples from both districts reported concentrations above the permissible limit of tyramine (25 mg/L). For the relationship with its physicochemical characteristics, only a significant relationship was found between acidity percentage and histamine content (r = 0.502).

Multicore Magnetic Nanoparticles Coated with Oligomeric Micelles: Characterization and Potential for the Extraction of Contaminants over a Wide Polarity Range.

Oligomeric micelles from sodium undecylenate (oSUD) were chemisorbed to magnetic iron oxide nanoparticles (MNPs) through a single-step synthetic route involving the simultaneous nanoparticle formation and functionalization in an aqueous medium. The resulting spherical nanoparticles (MNPs-oSUD) consisted of a concatenation of iron oxide cores, with an average size of 7.7 nm, bound by oSUD micelles (particle average diameter of ca. 200 nm). Micellar coverage was ∼50% of the MNP-oSUD (by weight) and offered multiple retention mechanisms (e.g., dispersion, hydrogen bonding, polar, and ionic) for solute solubilization while keeping it intact during analyte elution. The high density of micelles and variety of interactions provided by this sorbent rendered it highly efficient for the extraction of aromatic amines in a wide polarity range (log Kow values from -0.80 to 4.05) from textiles, urine, and wastewater. Extraction took 5 min, no cleanup or evaporation of the extracts was needed and the method, based on LC-MS/MS quantitation, proved matrix-independent. Recoveries for 17 aromatic amines in samples were in the range of 93%-123% while those with negative log Kow values were in the range of 69%-87%. Detection limits for aromatic amines in textiles (0.007-2 mg kg-1) were well below the limits legislated by the European Union (EU) (30 mg kg-1) and those in urine and wastewater (0.004-1.5 μg L-1) were at the level usually found in real-world applications. All the analyzed samples were positive in aromatic amines. The easy synthesis and excellent extraction properties of MNPs-oSUD anticipate their high potential not only for multiresidue analysis but also in other fields such as water remediation.

Ultra-sensitive HPLC-photochemical reaction-luminol chemiluminescence method for the measurement of secondary amines after nitrosation

A novel method for the determination of secondary amines at the nanomolar level was developed. The method is based on the nitrosation reaction of secondary amines, with the generated N-nitrosamines being measured using an HPLC separation, photochemical reaction, and chemiluminescence detection system. The efficient nitrosation of secondary amines was performed using sodium nitrite (200 mM) and acetic acid (0.8 M) at 80 °C over 60 min. Although compounds bearing OH and SH functional groups also underwent the nitrosation reaction, the sensitivity of these compounds was 1000 times lower than that of the secondary amines. Our method was applied to the determination of low molecular weight secondary amines, including dimethylamine, morpholine, pyrrolidine, diethylamine, and piperidine, giving method detection limits of 0.7 nM, 0.2 nM, 0.4 nM, 0.7 nM, and 1.5 nM, respectively. The calibration curves were linear in the range of 5–100 nM. We then applied this method for the detection and quantification of these secondary amines in samples of tap water, river water, treated wastewater, and sea water. Dimethylamine was detected at concentrations up to 15.4 nM, <0.7 nM, and 48.5 nM in tap water, river water, and treated wastewater samples, respectively, with recoveries ranging from 94 to 103%. Other amines were also detected at nanomolar levels. These results indicate that our proposed method can be applied to the analysis of secondary amines in various environmental water samples. To the best of our knowledge, the proposed method is one of the most sensitive and selective methods for the determination of secondary amines without pre-concentration steps.

Survivability and reactivity of glycine and alanine in early oceans: effects of meteorite impacts.

Prebiotic oceans might have contained abundant amino acids, and were subjected to meteorite impacts, especially during the late heavy bombardment. It is so far unknown how meteorite impacts affected amino acids in the early oceans. Impact experiments were performed under the conditions where glycine was synthesized from carbon, ammonia, and water, using aqueous solutions containing (13)C-labeled glycine and alanine. Selected amino acids and amines in samples were analyzed with liquid chromatography-mass spectrometry (LC/MS). In particular, the (13)C-labeled reaction products were analyzed to distinguish between run products and contaminants. The results revealed that both amino acids survived partially in the early ocean through meteorite impacts, that part of glycine changed into alanine, and that large amounts of methylamine and ethylamine were formed. Fast decarboxylation was confirmed to occur during such impact processes. Furthermore, the formation of n-butylamine, detected only in the samples recovered from the solutions with additional nitrogen and carbon sources of ammonia and benzene, suggests that chemical reactions to form new biomolecules can proceed through marine impacts. Methylamine and ethylamine from glycine and alanine increased considerably in the presence of hematite rather than olivine under similar impact conditions. These results also suggest that amino acids present in early oceans can contribute further to impact-induced reactions, implying that impact energy plays a potential role in the prebiotic formation of various biomolecules, although the reactions are complicated and depend upon the chemical environments as well.

Evolution of Volatile Compounds and Biogenic Amines throughout the Shelf Life of Marinated and Salted Anchovies (Engraulis encrasicolus)

Producers of processed anchovies have developed hazard analysis and critical control points (HACCP) to guarantee the quality of their products. Nonetheless there is a lack of objective data to determine products' shelf life. The quality of a product is usually established on the basis of its safety and organoleptic properties. These parameters were assessed by monitoring the profiles of volatile compounds and quantitating six biogenic amines in samples of two types of processed anchovies during their shelf life. With regard to biogenic amines, quantities were below the regulatory limits throughout shelf life, except when a temperature abuse was applied for marinated samples. Moreover, this work highlights an optimum volatile profile at 5 and 6 months of storage for salted and marinated anchovies, respectively. This is the result of a higher content of six aldehyde and nine ketone compounds, mainly from lipid oxidation.

Simultaneous determination of 33 primary aromatic amines of free state in fine pigments by ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry

A comprehensive analytical method based on ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-MS/MS) has been developed for the simultaneous determination of 33 primary aromatic amines (PAAs) in fine pigments such as gouache paint, oil painting pigment and acrylic paint. The primary aromatic amines in samples were extracted with acetonitrile. Then the extract was concentrated by centrifugation and nitrogen blow, finally diluted to 2 mL with methanol-water (1:9, v/v) and filtered through 0. 22 im membrane before UPLC-MS/MS analysis. The analytes were separated on a BEH Phenyl column (100 mm x 2. 1 mm, 1. 7 1µm) with 0. 07% (v/v) formic acid in methanol-water as mobile phases in gradient elution. The PAAs were detected by UPLC-MS/MS under multiple reaction monitoring (MRM) mode and quantified by the internal standard method. The separation conditions, fragment voltages and collision energies were optimized. The impacts of extraction times, extraction solvents and concentration methods on recoveries were studied. The limits of detection and limits of quantitation for the 33 primary aromatic amines were 5-50 µg/kg and 15-150 µg/kg respectively. The mean recoveries of three different dye products at three spiked levels were 70. 1% - 115. 8%. The relative standard deviations were 2. 1% - 15%. The expenmental results indicated that the method is simple, rapid, sensitive, accurate and can meet the requirements for the determination.

Effect of storage temperature on the quality of dry fermented sausage Poličan

The influence of different storage temperatures (5&amp;deg;C and 15&amp;deg;C) on the quality of vacuum-packed dry fermented sausage Poličan was determined. The salami mixture, finished salamis (the maturing period of 30 days), and salamis stored for 30, 60, 90, and 120 days were analysed. The analyses performed (physical/chemical, sensory, microbiological) found no differences in sensory properties or basic physical/chemical and microbiological parameters in the products after storage under different temperature conditions for 120 days. When stored at 15&amp;deg;C, the total content of biogenic amines in samples was higher than that for samples stored at 5&amp;deg;C with statistical differences P &amp;le; 0.05. If the principles of good manufacturing practice are observed at all phases of the technological process, the storage temperature of 15&amp;deg;C does not represent a risk as the consequent concentration of biogenic amines and polyamines remains extremely low. &amp;nbsp;

Development of single‐drop microextraction and simultaneous derivatization followed by GC‐MS for the determination of aliphatic amines in tobacco

In this work, for the first time, headspace (HS) single-drop microextraction and simultaneous derivatization followed by GC-MS was developed to determine the aliphatic amines in tobacco samples. In the HS extraction procedure, the mixture of derivatization reagent and organic solvent was employed as the extraction solvent for HS single-drop microextraction and in situ derivatization of aliphatic amine in the samples. Fast extraction and simultaneous derivatization of the analytes were performed in a single step, and the obtained derivatives in the microdrop extraction solvent were analyzed by GC-MS. The optimized experiment conditions were: sample preparation temperature of 80 degrees C and time of 30 min, HS extraction solvent (the mixture of benzyl alcohol and 2,3,4,5,6-pentafluorobenzaldehyde) volume of 2.0 microL, extraction time of 90 s. With the optimal conditions, the method validations were also studied. The method has good linearity (R(2) more than 0.99), accepted precision (RSD less than 13%), good recovery (98-104%) and low limit of detection (0.11-0.97 microg/g). Finally, the proposed technique was successfully applied to the analyses of aliphatic amines in tobacco samples of seven different brands. It was further demonstrated that the proposed method offered a simple, low-cost and reliable approach to determine aliphatic amines in tobacco samples.

Formation of Biogenic Amines in Chicken Meat Stored under Modified Atmosphere

The aim of the study was to investigate the effects of two modified atmospheres with a different combination of gases on selected groups of microorganisms and on concentrations of biogenic amines (BAs) in samples of poultry breast muscle. The samples were packaged under modified atmosphere A (75% O2 a 25% CO2) or B (75% N2 and 25% CO2) and stored at temperatures from +2 to +4 °C for 14 days. During the storage period, O2 concentrations in modified atmosphere A (MA A) decreased from the initial 74.8 ± 0.3% to 55.9 ± 6.6% at the end of the storage period. In all samples, counts of psychrotrophic bacteria counts, Brochothrix thermosphacta, lactic acid bacteria and coliform microorganism were determined. The tests were made on the packaging day, and then after three, nine and fourteen days of storage. At the end of the storage period, higher numbers of psychrotrophic bacteria (6.5 ± 0.7 log10 cfu g-1), Brochothrix thermosphacta (4.8 ± 0.3 log10 cfu g-1) and lactic acid bacteria (1.7 ± 0.4 log10 cfu g-1) were found on samples packaged under MA A. Samples packaged under modified atmosphere B on the other hand contained higher numbers of coliform bacteria (4.1 ± 0.6 log10 cfu g-1) at the end of the storage period. In addition to microbiological indicators, concentrations of biogenic amines (putrescine, cadaverine, histamine, tyramine, spermine, spermidine and β-phenylethylamine) were also determined. In fresh samples and after three days of storage, only spermine and spermidine were found. After 9 and 14 days, also other BAs were detected. The biogenic amine totals at the end of the storage period was 60.0 ± 13.2 mg kg-1 in samples packaged under MA A and 129.0 ± 41.3 mg kg-1 in samples packaged under MA B. The most abundantly represented biogenic amines in samples packaged under MA A were putrescine and spermine (49.7 and 24.8%, respectively, at the end of the storage period), and putrescine and cadaverine in samples packaged under MA B (47.0 and 32.9 %, respectively, at the end of the storage period).

Detection of cometary amines in samples returned by Stardust

Abstract— The abundances of amino acids and amines, as well as their enantiomeric compositions, were measured in samples of Stardust comet‐exposed aerogel and foil using liquid chromatography with UV fluorescence detection and time of flight mass spectrometry (LC‐FD/ToF‐MS). A suite of amino acids and amines including glycine, L‐alanine, β‐alanine (BALA), γ‐amino‐n‐butyric acid (GABA), ɛ‐amino‐n‐caproic acid (EACA), ethanolamine (MEA), methylamine (MA), and ethylamine (EA) were identified in acid‐hydrolyzed, hot‐water extracts of these Stardust materials above background levels. With the exception of MA and EA, all other primary amines detected in comet‐exposed aerogel fragments C2054,4 and C2086,1 were also present in the flight aerogel witness tile that was not exposed to the comet, indicating that most amines are terrestrial in origin. The enhanced relative abundances of MA and EA in comet‐exposed aerogel compared to controls, coupled with MA to EA ratios (C2054,4: 1.0 ± 0.2; C2086,1: 1.8 ± 0.2) that are distinct from preflight aerogels (E243–13C and E243–13F: 7 ± 3), suggest that these volatile amines were captured from comet Wild 2. MA and EA were present predominantly in an acid‐hydrolyzable bound form in the aerogel, rather than as free primary amines, which is consistent with laboratory analyses of cometary ice analog materials. It is possible that Wild 2 MA and EA were formed on energetically processed icy grains containing ammonia and approximately equal abundances of methane and ethane. The presence of cometary amines in Stardust material supports the hypothesis that comets were an important source of prebiotic organic carbon and nitrogen on the early Earth.

Biogenic amines in Turkish type pickled cabbage: Effects of salt and citric acid concentration

Pickled cabbage in brine is one of the traditional fermented products in Turkey. The effects of salt content (6, 8, 10 or 12%) and citric acid concentration (0 or 1%) on the production of biogenic amines in Turkish type pickled cabbage were investigated. Concentrations of putrescine, cadaverine, tryptamine, spermidine, spermine, tyramine and histamine were determined in 8 pickled cabbage samples, 4 of them contained citric acid and the remaining 4 samples contained no citric acid. Numbers of LAB (lactic acid bacteria), enterobactericeae and halophilic microorganisms of samples were determined during fermentation. Amounts of biogenic amines in samples containing 6, 8 or 10% salt and 1% citric acid were found lower than those in samples without citric acid. On the other hand, the highest concentrations of biogenic amines were observed in the sample containing 10% salt and no citric acid (P<0.05). There was a correlation between amounts of biogenic amines and numbers of LAB. Pickled cabbages supplied from the markets had small amounts of biogenic amines.

A survey of biogenic amines in Chinese rice wines

Fourteen Chinese rice wines from four rice wine-making regions of China were analyzed for the first time, using HPLC with diode array detection after pre-column derivatization with dansyl chloride. The results showed that Chinese rice wines contained the five biogenic amines histamine, tyramine, cadaverine, spermine and spermidine. Histamine was detected in all samples (100%), followed by spermine (93%), cadaverine (87%), tyramine (79%) and spermidine (79%). The mean total level of biogenic amines in samples was 107 mg/l with a range from 39.30 to 241 mg/l. These levels are below the level that may elicit direct adverse reactions for most consumers. However, patients being treated with monoamine oxidase inhibitors should be aware of the presence of amines in rice wines and limit their consumption.

Determination of isocyanates, aminoisocyanates and amines in air formed during the thermal degradation of polyurethane.

An air sampling method for the determination of isocyanates, aminoisocyanates and amines formed during the thermal degradation of polyurethane (PUR) is presented. The method is based on the collection of air samples using impinger flasks containing di-n-butylamine (DBA) in toluene with a glass fibre filter in series. Isocyanates are derivatized with DBA to urea derivatives, and amines are derivatized in a subsequent work-up procedure with ethyl chloroformate (ET) to carbamate esters. Amine, aminoisocyanate and isocyanate derivatives were characterized using liquid chromatography-time of flight mass spectrometry (LC-TOFMS) and liquid chromatography-chemiluminescent nitrogen detection (LC-CLND). Quantification was performed by LC-MS, monitoring molecular ions [MH]+ in the electrospray mode. The instrumental detection limits for amines, aminoisocyanates and isocyanates were in the ranges 30-40, 2-3 and 3-70 fmol, respectively. Thermal degradation products of PUR were observed in high concentrations during welding in district heating pipes and PUR-coated metal sheets. Eleven isocyanates, three amines and five aminoisocyanates were identified. The concentrations of isocyanates, aminoisocyanates and amines in samples collected in the smoke close to the welding spot were in the ranges 150-650, 4-290 and 1-70 ppb, respectively. In samples collected in the breathing zone, isocyanates and aminoisocyanates were observed in the ranges 9-120 and 4-19 ppb, respectively. The compounds were present in both gas and particle phases. Volatile compounds dominated in the gas phase, whereas less volatile compounds dominated in the particle phase. The method presented makes it possible to sample and determine amines and aminoisocyanates, in addition to isocyanates. The need to monitor these compounds is clearly illustrated by the high concentrations found during the thermal degradation of PUR.

The evaluation of interdigitated array electrodes for measurement of catecholamines and indoleamines

The use of Interdigitated Array (IDA) Microelectrodes for detection of low levels of biogenic amines has been demonstrated in stationary solutions and flow systems [M. Morita, et al., Electrochemica Acta 42 (20--21) (1997) 3177--3183]. This technique is highly sensitive. We have evaluated this technology as applied to High Pressure Liquid Chromatography with Electrochemical Detection (HPLC-EC) for analysis of microdialysate and tissue samples. With this new technology we demonstrated a x 10 fold increase in sensitivity in comparison to our existing technology. We are now able to detect dopamine at a level of 53 x 10(-18) moles on column and serotonin at 26 x 10(-18) moles on column. This technology now permits analysis of biogenic amines in samples from brain areas not previously amenable to this type of experiment.

Spectrofluorimetric Evaluation of Total Aliphatic and Aromatic Amines in Well Waters and Wastewaters

A simple and rapid spectrofluorimetric method is described for the determination of aliphatic and aromatic amines on the basis of ammonia and aniline, respectively. Aromatic amines in samples were reacted at pH 5.5 with fluram immoblised on an Octadecylsilane Solid Phase Extraction (ODS-SPE) cartridge. The produced pyrrolinones were adsorbed on SPE and separated from the aliphatic amines. Analysis of these compounds was carried out by elution of SPE with 1 ml Tetrahydrofuran (THF) and determination of fluorescence intensity at excitation wavelength 400 nm and emission wavelength 475 nm. Aliphatic amines after passing from SPE were collected and reacted with fluram at pH 9.2, and extracted into dichloromethane at pH 3 and quantitated fluorimetrically. Linear dynamic ranges and detection limits (LOD) were 1–20, 0.43 mg 1−1 and 1-200, 0.39 μg 1−1 for ammonia and aniline, respectively. The proposed method was successfuly applied for the evaluation of these compounds in local well waters and municipality wastewaters.

Determination and Contents of Non-Volatile Amines in Soybean Paste and Soy Sauce.

A liquid chromatographic (LC) analysis for the determination of seven amines, tyramine (Tym), histamine (Him), phenethylamine (Phm), putrescine (Put), cadaverine (Cad), spermidine (Spd) and spermine (Spm) in soybean paste (Miso), soy sauce (Shoyu) and its products was studied. The amines in the sample were extracted with 0.1N HCl and applied to a column of Amberlite CG-50 and derivatized with dansyl chloride for the application to the liquid chromatography. The LC separations were performed on a Finepak SIL C18S column with an acetonitrile-water elution gradient. The amines were confirmed by TLC for Him and by GC-MS for others with ethyloxycarbonyl derivatives. In the survey of commercial samples by this method, most of Miso samples and ann of Shoyu samples were found to contain these 7 amines. Tym and Him were determined in the range of nd-194, nd-177 μg/g in every kind of Miso, and 95.8-356, 62.8-232 μg/g in Shoyu and its products as average which were higher than the other amines. Shoyu, in general, had higher Him and Tym contents than Miso samples. However the contents of the other amines in both Shoyu and Miso samples were the same levels. It was considered that Tym, Him and Phm were produced by microorganism in a manufacturing process because these amines were not detected from such raw materials as koji (malted rice) and soy beans of Miso and Shoyu. Put, Cad, Spd and Spm were originated from the raw materials, because the contents of these amines in the samples were nearly the same as those of raw materials.

Direct analysis of free amines in salt solutions at sub-ppm levels by gas-liquid chromatography

A method is described for trace analysis of amines in salt solutions after an alkali treatment followed by direct sample injection. Different parameters that may influence the analysis have been investigated, including sample handling and storing, injector temperature, injector impregnation, pH of the solution, type of salt matrix and detector response where concentration or sample volume is varied. The determination limit is of the order of 10 ppb★ for most amines where the decrease in sensitivity for high-boiling amines caused by increased peak broadening can be compensated for by the use of large sample volumes (up to 25 μl). The average precision is ca. 2% at an amine concentration of 4 ppm, which is roughly the same as when the amines occur in pure water or in an organic solvent. The method is now routinely used in our laboratory for analysis of amines in samples obtained from workplace atmosphere measurements, where the amines are usually collected in a dilute acidified aqueous absorbing solution.

Separation and identification of aliphatic amine derivatives with a new fluorescent reagent using high-performance liquid chromatography and thin-layer chromatography

The use of 1,2-naphthoylenebenzimidazole-6-sulphochloride has been proposed as the reagent for derivatization of aliphatic amines prior to their separation, identification and quantitation both in HPLC and in TLC. The reaction of amines with this compound is quantitative and highly fluorescent derivatives are formed that provide favourable detection limits and sensitivity as compared to Dansyl derivatives of aliphatic amines. Actual detection limits achieved correspond to ca. 10−10 mol of the amine in a spot after elution from the thin-layer plate and to ca. 5·10−14 mol of the amine in a sample volume of 10 μl injected into the liquid chromatograph. The use of this derivatization reagent offers good potential for the analysis of trace amounts of amines in environmental samples and in biological material.