Determination of 6 biogenic amines in food using high-performance liquid chromatography-tandem mass spectrometry without derivatization.

A rapid and simple method for the determination of 6 biogenic amines (BAs) in food was established on HPLC-MS /MS without derivatization. Samples were extracted with 5% perchloric acid and cleaned with n-hexane for lipid removal. The analytes were separated on Waters XBridge® HILIC (150 mm × 2.1 mm, 3.5 µm) and analyzed with multiple-reaction monitoring (MRM) mode after positive electrospray ionization on HPLC-MS/MS. Good linearity with high correlation coefficient was obtained between 10-1000 µg/L for cadaverine (CAD), putrescine (PUT), tyramine (TYR) and 2-phenylethylamine (2-PHE) and between 1-100 µg/L for histamine (HIS) and tryptamine (TRY), with the detection limits of the method ranging from 0.1 mg/kg for HIS and TRY, and 1.0 mg/kg for CAD, PUT, TYR and 2-PHE, which are under the residue limit of Chinese regulation. Spiking experiments demonstrated good recoveries between 70.2-114.6%, with relative standard deviations (RSDs) between 0.44-13.01%. This method was validated for BAs determination in liquor, fermented meat products, vegetable products, soybean products, dairy products, seafood and its derived products. These results promise high feasibility for BAs monitoring in various food with easy-to-operate and fast sample preparation process, stable analysis on HPLC-MS/MS without derivatization.

Unmodified cellulose filter paper, a sustainable and affordable sorbent for the isolation of biogenic amines from beer samples.

While current trends in Green Analytical Chemistry aim at reducing or simplifying sample treatment, food usually comprises complex matrices where direct analysis is not possible in most cases. In this context, sample treatment plays a pivotal role. Biogenic amines are naturally formed in many foodstuffs due to the action of microorganisms, while their presence has been associated with adverse health effects. In this work, the extraction of seven biogenic amines (cadaverine, histamine, phenylethylamine, putrescine, spermidine, spermine, and tyramine) from beer samples has been simplified using laboratory filter paper as sorbent without any further modification. The analysis of the eluates by direct infusion mass spectrometry reduces the time of analysis, increasing the sample throughput. This simple but effective method enabled the determination of the analytes with limits of detection as low as 0.06 mg L-1 and relative standard deviations better than 11.9%. The suitability of the method has been assessed by analyzing eight different types of beers by the standard addition method.

Simultaneous determination of eight biogenic amines in the traditional Chinese condiment Pixian Douban using UHPLC-MS/MS.

A UHPLC-MS/MS method was developed to simultaneously determine eight biogenic amines (BAs) in Pixian Douban. Under optimal conditions, the linear ranges of determination were 5-1000 µg/L (that of spermine was 8-1000 µg/L). Correlation coefficients ranged from 0.9955 to 0.9987. The limits of detection were 0.11-5.5 µg/L. The matrix effect and analytical performance of the present method were evaluated, and the eight BAs were analyzed by this method in 19 samples, indicating the potential pollution of BAs in chili oil Pixian Douban.

Ultrasound-assisted dispersive solid-phase extraction combined with reversed-phase high-performance liquid chromatography-photodiode array detection for the determination of nine biogenic amines in canned seafood.

This work describes an ultrasound-assisted dispersive solid-phase extraction method combined with reversed-phase high-performance liquid chromatography-photodiode array detection (UADSPE-RPLC-PDA) for the determination of nine common biogenic amines (BAs) in canned seafood. The pretreatment extraction solvent, ultrasonic treatment duration, and derivatization conditions were optimized. The method was validated on the basis of the limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy and successfully applied to analyze four canned fish, two canned shrimp and four canned shellfish samples. LODs of 0.08-0.25 mg kg-1 were achieved, and the correlation coefficient of determination was 0.9994-0.9997. The method had high precision and accuracy, with relative standard deviations (RSDs) and recoveries of 0.44 to 6.83% and 72.57 to 99.74%, respectively, suggesting the effectiveness of ultrasound-assisted extraction at increasing the solubility of the target analytes in the solvent system and the feasibility of UADSPE-RPLC-PDA for determining trace BAs in canned seafood.

Strong cation- and zwitterion-exchange-type mixed-mode stationary phases for separation of pharmaceuticals and biogenic amines in different chromatographic modes.

A set of new mixed-mode ion-exchange stationary phases is presented. The backbone of organic selectors is formed by a linear hydrocarbon chain, which is divided into two parts of various lengths by a heteroatom (oxygen or nitrogen). In all studied cases, there is a sulfonic acid moiety as the terminal group. Therefore, selectors bearing oxygen gave rise to strong cation ion-exchange stationary phases, while selectors with an embedded nitrogen atom (inducing a weak anion exchange capacity) were used to create zwitterion ion-exchange stationary phases. The new mixed-mode stationary phases were chromatographically evaluated in high performance liquid chromatography (HPLC) and supercritical fluid chromatography (SFC) using isocratic elution conditions to disclose their chromatographic potential. In HPLC mode, aqueous-rich reversed phase chromatography, acetonitrile-rich hydrophilic interaction liquid chromatography and methanolic ion-exchange chromatography mobile phases were employed. In these chromatographic modes, retention factors and selectivity values for a test set of basic and zwitterionic analytes were determined. The results were compared and principal component analysis for each chromatographic mode was performed. For all chromatographic modes, the component 1 in the principal component analysis reflected the elution order. The application of different mobile phases on a particular column resulted not only in variation in retention, but also in modified selectivity, and different elution order of the analytes. The orthogonality of the elution order depending on the employed mobile phase conditions was especially reflected for structurally closely related analytes, such as melatonin and N-acetyl-serotonin, tryptamine and serotonin or noradrenalin and octopamine. However, ion-exchange interactions remain the main driving force for retention. From all investigated stationary phases, the SCX 2 (C5-linker and C4-spacer) seems to be the best choice for the separation of basic analytes using different mobile phase conditions.

Two-dimensional separation by sequential injection chromatography.

Sequential injection chromatography (SIC) is an alternative for fast chromatographic separations with low consumption of organic solvents. However, its separation capacity is restricted by the use of short chromatographic columns and the limitations for gradient elution. The present work aimed to expand the analytical capacity of SIC by exploiting a multidimensional approach with two chromatographic columns, different in their separation mechanisms, which increased the selectivity and peak resolution. The viability of the proposal was demonstrated by separation of aromatic biogenic amines (histamine, tyramine, phenylethylamine, and tryptamine), whose unidimensional separation was not achieved either by using cyanopropyl or C18 chromatographic columns. In the two-dimensional approach, the fraction of the eluate unresolved in the first dimension (containing tyramine and phenylethylamine) was collected in a sampling loop and, subsequently, inserted in the second chromatographic dimension (heart-cutting mode). Under the optimized conditions, the first chromatographic dimension was based on a cyanopropyl monolithic column and an aqueous mobile phase composed of phosphoric acid solution, pH 2.5, while the second dimension employed a C18 superficially porous particle column and a mobile phase composed of acetonitrile and phosphoric acid aqueous solution, pH 2.5 (7:93, v/v). The total analysis time was 8 min, and a resolution of 1.72 was achieved between the nearest peaks (tyramine and phenylethylamine). Linear responses were obtained within 10 and 50 mg L-1 (r > 0.997), with detection limits estimated at 2.7, 7.7, 1.9, and 0.3 mg L-1, for histamine, tyramine, phenylethylamine, and tryptamine, respectively, and a coefficient of variation of 3.0% (n = 12).

Designed multifunctional visual observation of magnetic ionic liquid coupling with microwave-assisted derivatization for determination of biogenic amines.

A multifunctional visual observation of magnetic ionic liquid (MIL) benzyltrioctylammonium thiocyanatecobalt (II) [N8,8,8,B+]2[Co(SCN)42-] with the long-chain alkyl and benzyl group structures was designed and synthesized as microextraction phase. Designed new structural MIL displays good hydrophobicity, high extraction capacity for both aromatic and aliphatic compounds, and has obvious color markers (blue color) which is easy visual separation from aqueous solution through a magnet. In the present work, a green, efficient and rapid samples pretreatment method based on simultaneous derivatization and extraction of aromatic (tyramine, histamine, phenylethylamine, tryptamine) and aliphatic (spermidine and spermine) biogenic amines (BAs) were performed. Microwave-assisted derivatization coupled with MIL-dispersive liquid-liquid microextraction (DLLME) was established for the determination of six BAs in different food samples via HPLC. The method was successfully applied for the analysis of beer and milk samples, and the recoveries of analytes were 93.0-110.3% and 91.2-111.6%, respectively. The limits of detection (LODs) were 0.51-1.49 µg L-1 for six BAs. These results have demonstrated that the proposed method has offered an effective, accurate, and sensitive methodology for BAs residue detection in food sample, and this method has great potential for the routine analysis of large numbers of samples on measuring different kinds of compounds.

Recent advances in Baijiu analysis by chromatography based technology-A review.

Baijiu, a conventional fermented beverage with thousands history, plays a crucial part in physical health of people and social culture in China. The application of high-throughput screening and confirmation of flavor components in the field of authenticity identification and potential function has attracted more and more attention and interest of researchers. With more attention to health, pesticides residues, phthalates, biogenic amines and other hazardous substances remained in Baijiu have also become the quality parameters concerned by consumers. This review aims to present updated and critical overview on the substances analysis of Baijiu by means of hyphenated chromatographic techniques based on various pretreatment approaches in recent years. Subsequently, the advance and main direction of Baijiu composition analysis were evaluated and prospected.

Solid phase "on-situ" quadraplex isotope dimethyl labeling for the analysis of biogenic amines in beers by liquid chromatography-high resolution mass spectrometry.

A simple magnetization method was developed for the preparation of magnetic materials from conventional solid phase packing though coprecipitation and solvothermal approaches. And the prepared magnetic materials were used for magnetic solid phase extraction (MSPE) of biogenic amines (BAs) from beers. Furthermore, to improve the analytical throughput, a solid phase "on-situ" quadraplex isotope dimethyl labeling method was developed for the quantification of BAs by liquid chromatography-high resolution mass spectrometry (LCHRMS). Compared to conventional in-solution labeling, the "on-situ" labeling could simplify the sample preparation procedure and efficiently remove the residuals such as inorganic salts and excessive labeling reagents. The quadraplex labeling, which enabled three real samples and one internal standard sample to be analyzed simultaneously in a single LCHRMS run. For the tested 8 BAs (cadaverine, phenethylamine, spermine, spermidine, tyramine, histamine, putrescine and tryptamine), LODs of 0.02-0.05 µg/L and LOQs of 0.05-0.1 µg/L were achieved at good reproducibility (RSD of 0.5-4.6% and 2.2-7.0% for intra- and inter-day reproducibility, respectively). With this method, six beer samples were analyzed, and these 8 BAs were all detected in the range of low µg/L to 2.9 mg/L, which were lower than maximal residual level (MRL) required in the regulations of China and EU.

Application of SPME supported by ionic liquids for the determination of biogenic amines by MEKC in clinical practice.

The analysis of biogenic amines (BAs) and their metabolites is helpful for the diagnosis of central nervous system disorders and other neuroendocrine and cancer disturbances. In the study, a developed micellar electrokinetic chromatography method, coupled with diode array detection (MEKC-DAD), was validated to monitor levels of adrenaline (A), noradrenaline (NA), dopamine (DA), L-Tryptophan (L-Tryp) and L-Tyrosine (L-Tyr) in real human urine samples. These neurotransmitters were isolated from urine samples using solid-phase microextraction (SPME) and methanol containing 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid as the desorption phase. The method was linear for DA, A and L-Tyr in the range of 0.5-20 µg/mL and for NA and L-Tryp in the range of 0.25-20 µg/mL. The good linearity for BAs was confirmed by the correlation coefficient (R2) from 0.9989 for A to 0.9997 for NA and L-Tryp, respectively. The validation assays for accuracy, precision, limit of detection, limit of quantification, absolute recovery, and stability of the analytes were consistent with the requirements recommended by the FDA and ICH guidelines. Next, the validated SPME-MEKC method was successfully used for the quantification of A, NA, DA, L-Tryp and L-Tyr in real human urine samples collected from pediatric patients suffering from neuroblastoma, ganglioneuroblastoma, Wilms' tumor, rhabdoid tumor and lipoblastomatosis, as well as from healthy volunteers. Finally, the levels of BAs in cancer patients were evaluated as to whether they can be used as biomarkers of various health disturbances.

Perylene Bisimide Aggregates as Probes for Subnanomolar Discrimination of Aromatic Biogenic Amines.

Perylene bisimide derivatives show peculiar physical chemical features, such as a highly conjugated system, high extinction coefficients and elevated fluorescence quantum yields, making them suitable for the development of optical sensors of compounds of interest. In particular, they are characterized by the tendency to aggregate into π-π stacked supramolecular structures. In this contribution, the behavior of the PBI derivative N, N'-bis(2-(trimethylammonium)ethylene)perylene bisimide dichloride was investigated both in aqueous solution and on solid support. The electronic communication between PBI aggregates and biogenic amines was exploited in order to discriminate aromatic amines down to subnanomolar concentrations by observing PBI fluorescence variations in the presence of various amines and at different concentrations. The experimental findings were corroborated by density functional theory calculations. In particular, phenylethylamine and tyramine were demonstrated to be selectively detected down to 10-10 M concentration. Then, in order to develop a surface plasmon resonance (SPR) device, PBI was deposited onto a SPR support by means of the layer-by-layer method. PBI was deposited in the aggregated form and was demonstrated to preserve the capability to discriminate, selectively and with an outstanding analytical sensitivity, tyramine in the vapor phase and even if mixed with other aromatic amines.

Prediction of the Biogenic Amines Index of Poultry Meat Using an Electronic Nose.

The biogenic amines index of fresh chicken meat samples during refrigerated storage was predicted based on the headspace analysis using an electronic nose equipped with an array of electrochemical sensors. The reference biogenic amines index values were obtained using dispersive liquid⁻liquid microextraction⁻gas chromatography⁻mass spectrometry. A prototype electronic nose with modular construction and a dedicated sample chamber was used to rapidly analyze the volatile fraction of chicken meat samples, with a single measurement time of five minutes. Back-propagation artificial neural network was used to estimate the biogenic amines index of the samples with a determination coefficient of 0.954 based on ten-fold stratified cross-validation. The results indicate that the determination of the biogenic amines index is a good reference method for studies in which the freshness of meat products is assessed based on headspace analysis and fingerprinting, and that the described electronic device can be used to assess poultry meat freshness based on this value with high accuracy.

Indicator Layers Based on Ethylene-Vinyl Acetate Copolymer (EVA) and Dicyanovinyl Azobenzene Dyes for Fast and Selective Evaluation of Vaporous Biogenic Amines.

The article presents naked-eye methods for fast, sensitive, and selective detection of isopentylamine and cadaverine vapours based on 4-N,N-dioctylamino-4'-dicyanovinylazobenzene (CR-528) and 4-N,N-dioctylamino-2'-nitro-4'-dicyanovinylazobenzene (CR-555) dyes immobilized in ethylene-vinyl acetate copolymer (EVA). The reaction of CR-528/EVA and CR-555/EVA indicator layers with isopentylamine vapours caused a vivid colour change from pink/purple to yellow/orange-yellow. Additionally, CR-555/EVA showed colour changes upon exposure to cadaverine. The colour changes were analysed by ultraviolet⁻visible (UV/VIS) molecular absorption spectroscopy for amine quantification, and the method was partially validated for the detection limit, sensitivity, and linear concentration range. The lowest detection limits were reached with CR-555/EVA indicator layers (0.41 ppm for isopentylamine and 1.80 ppm for cadaverine). The indicator layers based on EVA and dicyanovinyl azobenzene dyes complement the existing library of colorimetric probes for the detection of biogenic amines and show great potential for food quality control.

A comparative analysis of derivatization strategies for the determination of biogenic amines in sausage and cheese by HPLC.

The six biogenic amines in sausage and cheese were analyzed by HPLC with UV detection after off-line derivatization with dansyl chloride, 9-fluorenylmethoxycarbonyl chloride, benzoyl chloride and dabsyl chloride, respectively. The results showed that both the off-line 9-fluorenylmethoxycarbonyl and dabsyl derivatization were not suitable for HPLC analysis of biogenic amines when batch injection was used because the derivatives were instable, whereas both the off-line dansyl and benzoyl derivatization were suitable for HPLC analysis of biogenic amines when batch injection was used, but the latter needed to maintain the derivatives at 4 °C to ensure that benzoylated tyramine was not degraded when waiting for the analysis. The off-line dansyl derivatization had an obvious advantage in the analysis of biogenic amines in sausage and cheese samples by HPLC combined with batch injection because the method has a wider linear range and higher sensitivity, accuracy, precision and stability of the derivatives.

Comparison of cation-exchange capillary columns used for ion chromatographic separation of biogenic amines.

The selectivity for 15 biogenic amines and amino acids shown by three capillary cation-exchange columns, IonPac CS19, CS12A and CS17 (250 × 0.4 mm ID, all from Thermo Fisher Scientific), exhibiting medium, medium low and ultra-low hydrophobicity, and either carboxylic or mixed carboxylic/phosphonic acid functional groups, was investigated. A mixed mode retention mechanism was revealed with ion-exchange, hydrophobic and hydrogen bonding interactions contributing to retention of polar organic molecules on these phases. The relative impact of these interactions was evaluated via the effect of concentration and pH of the eluent (methanesulfonic acid) on the retention of fifteen structurally similar biogenic amines and amino acids. Strong hydrogen bonding interactions were observed between the solute amino acid carboxylic groups and cation-exchange groups from the ion-exchangers. This is the first time retention data correlated with logP data has revealed clustering of the solutes in two groups, according to the presence or absence of a carboxylic acid functional group. In addition, stronger retention behaviour was found for the IonPac CS12A cation-exchanger, containing both carboxylic and phosphonic functional groups. Further assessment of the orthogonality plots of retention factors for the three stationary phases revealed that the columns exhibited different complimentary selectivity that can be utilised to achieve specific separations.

Electromembrane extraction of biogenic amines in food samples by a microfluidic-chip system followed by dabsyl derivatization prior to high performance liquid chromatography analysis.

In the present research, an on-chip electromembrane extraction coupled with high performance liquid chromatography was developed for monitoring the trace levels of biogenic amines (BAs), including histamine, tryptamine, putrescine, cadaverine and spermidine in food samples. A porous polypropylene sheet membrane impregnated with an organic solvent was placed between the two parts of the chip device to separate the channels. Two platinum electrodes were mounted at the bottom of these channels, which were connected to a power supply, providing the electrical driving force for migration of ionized analytes from the sample solution through the porous sheet membrane into the acceptor phase. BAs were extracted from 2 mL aqueous sample solutions at neutral pH into 50 µL of acidified (HCl 90 mM) acceptor solution. Supported liquid membrane including NPOE containing 10% DEHP was used to ensure efficient extraction. Low voltage of 40 V was applied over the SLMs during extraction time. The influences of fundamental parameters affecting the transport of BAs were optimized. Under the optimized conditions, the relative standard deviations based on four replicate measurements were less than 8.0% and limit of detections were in range of 3.0-8.0 µg L-1. Finally, the method was successfully applied to determinate BAs in the food samples and satisfactory results (recovery > 95.6) were obtained.

Determination of Biogenic Amines in Seawater Using Capillary Electrophoresis with Capacitively Coupled Contactless Conductivity Detection.

A rapid and green analytical method based on capillary electrophoresis with capacitively coupled contactless conductivity detection (C4D) for the determination of eight environmental pollutants, the biogenic amines (putrescine, cadaverine, spermidine, spermine, tyramine, 2-phenylamine, histamine and tryptamine), is described. The separation was achieved under normal polarity mode at 24 °C and 25 kV with a hydrodynamic injection (50 mbar for 5 s) and using a bare fused-silica capillary (95 cm length × 50 µm i.d.) (detection length of 10.5 cm from the outlet end of the capillary). The optimized background electrolyte consisted of 400 mM malic acid. C4D parameters were set at a fixed amplitude (50 V) and frequency (600 kHz). Under the optimum conditions, the method exhibited good linearity over the range of 1.0⁻100 µg mL−1 (R² ≥ 0.981). The limits of detection based on signal to noise (S/N) ratios of 3 and 10 were ≤0.029 µg mL−1. The method was used for the determination of seawater samples that were spiked with biogenic amines. Good recoveries (77⁻93%) were found.

Competitive fluorescent pseudo-immunoassay exploiting molecularly imprinted polymers for the detection of biogenic amines in fish matrix.

We developed a competitive fluorescent molecularly imprinted polymer (MIP) assay to detect biogenic amines in fish samples. MIPs synthesized by precipitation polymerization using histamine as template were used in a batch binding assay analogous to competitive fluoroimmunoassays. Introducing a complex sample matrix, such as fish extract, into the assay changes the environment and the binding conditions, therefore the importance of the sample preparation is extensively discussed. Several extraction and purification methods for fish were comprehensively studied, and an optimal clean-up procedure for fish samples using liquid-liquid extraction was developed. The feasibility of the competitive MIP assay was shown in the purified fish extract over a broad histamine range (1 - 430µM). The MIP had the highest affinity towards histamine, but recognized also the structurally similar biogenic amines tyramine and tryptamine, as well as spermine and spermidine, providing simultaneous analysis and assessment of the total amount of biogenic amines.

A multi-purpose tool for food inspection: Simultaneous determination of various classes of preservatives and biogenic amines in meat and fish products by LC-MS.

This paper describes an innovative fast and multipurpose method for the chemical inspection of meat and fish products by liquid chromatography-tandem mass spectrometry. Solid-liquid extraction and low temperature partitioning were applied to 17 analytes, which included large bacteriocins (3.5kDa) and small molecules (organic acids, heterocyclic compounds, polyene macrolides, alkyl esters of the p-hydroxybenzoic acid, aromatic, and aliphatic biogenic amines and polyamines). Chromatographic separation was achieved in 10min, using stationary phase of di-isopropyl-3-aminopropyl silane bound to hydroxylated silica. Method validation was in accordance to Commission Decision 657/2002/CE. Linear ranges were among 1.25-10.0mgkg-1 (natamycin and parabens), 2.50-10.0mgkg-1 (sorbate and nisin), 25.0-200mgkg-1 (biogenic amines, hexamethylenetetramine, benzoic and lactic acids), and 50.0-400mgkg-1 (citric acid). Expanded measurement uncertainty (U) was estimated by single laboratory validation combined to modeling in two calculation approaches: internal (U = 5%) and external standardization (U = 24%). Method applicability was checked on 89 real samples among raw, cooked, dry fermented and cured products, yielding acceptable recoveries. Many regulatory issues were revealed, corroborating the need for enhancement of the current analytical methods. This simple execution method dispenses the use of additional procedures of extraction and, therefore, reduces costs over time. It is suitable for routine analysis as a screening or confirmatory tool for both qualitative and quantitative results, replacing many time consuming analytical procedures.

Isolation and identification of allergens and biogenic amines of Prosopis juliflora genotypes

Background: Prosopis, or mesquite (Prosopis juliflora (Sw.) DC.), was introduced in Saudi Arabia several decades ago and is heavily used in street, roadside, and park plantations. It shows great adaptation to the prevailing climatic conditions such as high temperature, severe drought, and salinity and spreads naturally in many parts of the Kingdom. This research was conducted to isolate allergen proteins and biogenic amines from the pollen grains of P. juliflora genotypes in Saudi Arabia from two regions, namely Al-Qassim and Eastern regions. Results: The results showed that 18 different allergen proteins were detected in P. juliflora genotypes, with molecular weight ranging from 14 to 97 kDa. Moreover, P. juliflora genotypes from the two studied regions contained eight biogenic amines, namely histamine, tyramine, tryptamine, ß-phenylethylamine, butricine, codapherine, spermidine, and spermine. All genotypes from the Al-Qassim region were found to contain all eight amines, while in the Eastern region, histamine was absent in three genotypes, spermine was absent in six genotypes, and spermidine was absent in three genotypes. Genotypes B23, E20, and E21 had the lowest biogenic amine quantity. Conclusions: All identified proteins from mesquite trees from both regions (Eastern and Al-Qassim) cause allergies in patients who are sensitive to pollen grains. Bioamines, except histamine and tyramine, were recorded at varying concentrations in different genotypes.