Determination of biogenic amines in alcoholic beverages by ion chromatography with suppressed conductivity detection and integrated pulsed amperometric detection

The determination of biogenic amines in alcoholic beverages is important to assess the potential risks associated with the consumption of high concentrations of these compounds. In addition, product storage conditions and the length of storage can cause the formation of biogenic amines that reduce product quality. We report a new method using cation-exchange chromatography with either suppressed conductivity, integrated pulsed amperometry, UV, or a combination of these detection techniques to determine biogenic amines in alcoholic beverages. The main objective was to provide a direct comparison between IPAD and suppressed conductivity detection for determining biogenic amines in alcoholic beverages. Suppressed conductivity is the simplest detection approach for determining putrescine, cadaverine, histamine, agmatine, phenylethylamine, spermidine, and spermine with good sensitivity (0.004-0.08 mg/l) and was used to evaluate the influence of storage time and conditions on the evolution of biogenic amines in alcoholic beverages. Integrated pulsed amperometric detection (IPAD) detects more biogenic amines than suppressed conductivity detection, enabling the detection of dopamine, tyramine, and serotonin. Tyramine was simultaneously determined by UV detection and IPAD to provide confirmation and ensure the accuracy of the analytical results. The linearity of biogenic amine responses was within 0.1-20 mg/l and peak area precisions were 0.24-4.97% for IPAD, suppressed conductivity-IPAD, and UV detection. The sensitivity for the 10 biogenic amines using the 3 detection techniques varied considerably from 0.004-1.1 mg/l and recoveries were within 85-122%.     

Direct automatic determination of biogenic amines in wine by flow injection-capillary electrophoresis-mass spectrometry

A capillary electrophoresis-electrospray mass spectrometry (CE-ESI-MS) method for the separation and determination of nine biogenic amines is proposed. Operational variables, such as the voltage, temperature, sheath liquid composition, flow-rate, and MS parameters, were optimized. Samples are injected in the hydrodynamic mode into a 75 cm x 50 microm ID coated capillary and separated by using 25 mM citric acid at pH 2.0. Heptylamine is used as internal standard. The experimental setup includes a flow manifold coupled to the CE system for automatic insertion of samples into the CE vials. The proposed method allows amines to be determined with limits of detection from 0.018 to 0.09 microg x mL(-1) and relative standard deviation (RSD) values from 2.4% to 5.0% (except 6.8% for histamine). The method was successfully used to determine biogenic amines in red and white wines.     

Analytical potential of 6-oxy-(N-succinimidyl acetate)-9-(2'-methoxycarbonyl) fluorescein for the determination of amino compounds by capillary electrophoresis with laser-induced fluorescence detection

The analytical potential of a fluorescein analogue, 6-oxy-(N-succinimidyl acetate)-9-(2'-methoxycarbonyl) fluorescein (SAMF), for the first time synthesized in our laboratory, as a labeling reagent for the labeling and determination of amino compounds by capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection was investigated. Biogenic monoamines and amino acids were chosen as model analytes to evaluate the analytical possibilities of this approach. The derivatization conditions and separation parameters for the biogenic amines were optimized in detail. The derivatization was performed at 30 degrees C for 6 min in boric acid buffer (pH 8.0). The derivatives were baseline-separated in 15 min with 25 mM boric acid running buffer (pH 9.0), containing 24 mM SDS and 12.5% v/v acetonitrile. The concentration detection limit for biogenic amines reaches 8 x 10(-11) mol.L(-1) (signal-to-noise ratio = 3). The application of CE in the analysis of the SAMF-derivatized amino acids was also exploited. The optimal running buffer for amino acids suggested that weak acidic background electrolyte offered better separation than the basic one. The proposed method was applied to the determination of biogenic amines in three different beer samples with satisfying recoveries varying from 92.8% to 104.8%. Finally, comparison of several fluorescein-based probes for amino compounds was discussed. With good labeling reaction, excellent photostability, pH-independent fluorescence (pH 4-9), and the resultant widely suited running buffer pH, SAMF has a great prospect in the determination of amino compounds in CE.     

Condensation nucleation light scattering detection for biogenic amines separated by ion-exchange chromatography.

A sensitive method of analysis for biogenic amines, putrescine, cadaverine, histamine and an amino acid precursor, histidine is described herein using ion-exchange chromatography and condensation nucleation light scattering detection. The method was successfully used for the analysis of biogenic amines in fish samples. The method offers a number of advantages: fast elution of analytes with no need for mobile phase conductivity suppression, no derivatization and no electrochemical activity for the analyte's detection. The 3 sigma detection limits for these compounds were found to range from 8 to 20 ng/ml.     

Recent advances in the application of capillary electromigration methods for food analysis

This article reviews the latest developments in the application of capillary electromigration methods for the analysis of foods and food components. Nowadays, methods based on CE techniques are becoming widely used in food analytical and research laboratories. This review covers the application of CE to analyze amino acids, biogenic amines, peptides, proteins, DNAs, carbohydrates, phenols, polyphenols, pigments, toxins, pesticides, vitamins, additives, small organic and inorganic ions, chiral compounds, and other compounds in foods, as well as to investigate food interactions and food processing. The use of microchips as well as other foreseen trends in CE analysis of foods is discussed. Papers that were published during the period June 2002-June 2005 are included following the previous review by Frazier and Papadopoulou (Electrophoresis 2003, 24, 4095-4105).     

CE determination of small ions: methods and techniques

This paper provides an overview on the current status of capillary electrophoresis (CE) in the analysis of inorganic and charged small organic species. The various CE strategies used to improve the separation of ionic analytes are summarized. Technical developments in the design of improved detection systems are described. A brief account of their advantages and limitations is given. The potential use of these devices for miniaturized CE systems is also described. Finally, special attention is focused on the on-capillary preconcentration techniques developed in attempts to overcome the poor detectability of CE. Recent review articles are frequently cited to provide readers with a source of information about pioneering work, theoretical treatments, and specific applications.     

Validation of an ultra high pressure liquid chromatographic method for the determination of biologically active amines in food

Biologically active amines include the so called biogenic amines, such as histamine, tyramine and cadaverine, and polyamines such as spermidine and spermine. Ultra high pressure liquid chromatography (UHPLC) is a new generation of separation techniques that takes full advantage of chromatographic principles to increase speed flow which drastically reduce analysis time. The aim of the present work was to validate a rapid method of UHPLC to detect the presence of biogenic amines and polyamines in food. Different food matrixes (wine, fish, cheese, and dry fermented sausage) were used in order to test the versatility of the method. The UHPLC method described in this article has been demonstrated as a reliable procedure to determine 12 biogenic amines and polyamines in less than 7 min of chromatographic elution. The method provides a satisfactory linearity and chromatographic sensitivity with a detection limit lower than 0.2 mg/L and a determination limit falling below 0.3 mg/L for all amines. The precision, in terms of relative standard deviation, was lower than 5% and the accuracy, as mean recovery, was between 93% and 98%, depending on the food matrix.     

Recent advances in the application of capillary electrophoresis to neuroscience

With fast separation times (seconds to minutes), minimal sample requirements (nanoliters to femtoliters), and excellent mass detection limits (femtomole to zeptomole), capillary electrophoresis (CE) is ideally suited for in vitro and in vivo sampling of neurological samples with a high degree of spatial resolution. Advances in extracellular fluid analysis employing improved microdialysis and push–pull perfusion sampling methodologies has enabled the resolution of neurotransmitters present in limited amounts using CE. Great progress has been made to resolve complex neuropeptides, amino acids, and biogenic amines in tissue and cell cultures. Finally, owing largely to the small volume sampling abilities of CE, investigations of single nerve cells, both invertebrate and mammalian, have been accomplished. These applications of CE to the advancement of neuroscience are presented.     

毛细管电泳在食品分析中的应用

介绍了近年来国内外毛细管电泳（CE）在食品分析中的应用,包括蛋白质、氨基酸、生物胺、维生素、碳水化合物、无机离子、有机酸、食品添加剂、农药和抗生素残留、生物毒素等食品中一些物质的测定。引用文献59篇。     

Biosensors for Biogenic Amines: The Present State of Art Mini-Review

The analysis of biogenic amines in fresh and processed food is of great importance not only for the potential risk these compounds have on human health, but also because these amines can perform as chemical indicators of food quality and enable the assessment of food processing conditions and/or microbial contamination.

A good option for a rapid detection of biogenic amines is the application of biosensors, as these devices enable the obtainment of results in a few minutes without pretreatment of the analyzed material. Biosensors for biogenic amines comprise various combinations of different enzymes for selective biorecognition and signal transduction systems and are based on different signal mechanisms. The present review gives a condensed overview of the recent developments and issues in the construction of biosensors for the detection of most common biogenic amines found in food and other protein-containing material.     

Determination of biogenic amines by capillary zone electrophoresis with conductometric detection

A capillary zone electrophoresis (CZE) method with conductometric detection of biogenic amines (cadaverine, putrescine, agmatine, histamine, tryptamine and tyramine) is described. The optimised background electrolyte was the following: 15 mM histidine + 5 mM adipic acid + 1.5 mM sulphuric acid + 0.1 mM ethylenediaminotetraacetic acid + 0.1% hydroxyethylcellulose + 50% methanol. A clear separation of six biogenic amines from other components of acidic sample extract was achieved within 10 min. Method characteristics, i.e., linearity (0-100 micromol/ml), accuracy (recovery 86-107%), intra-assay repeatability (2-4%), and detection limit (2-5 micromol/l) were evaluated. Low laboriousness, sufficient sensitivity, speed of analysis, and low running cost are important attributes of this method. The developed method was successfully applied on the determination of biogenic amines in selected food samples.     

Derivatization, stabilization and detection of biogenic amines by cyclodextrin-modified capillary electrophoresis-laser-induced fluorescence detection

o-Phthalaldehyde (OPA) derivatives of eight biogenic amines were stabilized at 5 degrees C by forming inclusion complexes with methyl-beta-cyclodextrin (MBCD). The derivatives were separated and detected by cyclodextrin-modified capillary electrophoresis (CE) with UV or laser-induced fluorescence (LIF) detection. Using a borate buffer, pH 9.0 consisting of ethanol and a mixture of negatively charged sulfobutylether-beta-cyclodextrin and neutral MBCD, baseline separation of the eight OPA derivatives was achieved within 25 min with high separation efficiencies. The detection limits (S/N=3) obtained by UV and LIF detection were determined to be 10 microM and 0.250 microM, respectively. Glutamic acid was added after the initial derivatization step to neutralize residual OPA which otherwise caused a significant interference, particularly when analysis was performed around the detection limit of the OPA derivatives. Important biogenic amines in fish, wine and urine were then derivatized and determined by CE-LIF. In the case of sole and rainbow trout, the results obtained were validated by an enzymatic assay using putrescine oxidase.     

毛细管电色谱-激光诱导荧光检测法分析食品中的生物胺

以4-氟-7-硝基-2,1,3-苯并氧杂恶二唑(NBD-F)为衍生化试剂,建立了食品中5种痕量生物胺(色胺、组胺、酪胺、亚精胺、精胺)的毛细管电色谱-激光诱导荧光检测(CEC-LIF)分析方法。采用50 mmol/L硼酸盐缓冲溶液(pH 8.0)作为衍生介质,在75℃条件下对生物胺进行衍生化反应25 min。生物胺衍生产物的最优色谱条件:固定相为C18毛细管电色谱柱,流动相为乙腈-乙酸铵(20 mmol/L,pH 8.0)(75∶25,v/v),辅助压力为6.9 MPa,分离电压为-8 kV,流速为0.03 mL/min。实验结果表明,生物胺的检出限(LOD,S/N=3)为0.1~1.0μg/L,加标回收率为78.3%~113.9%。该方法可成功用于加工和发酵食品中生物胺的测定,结果与传统HPLC法的检测结果无显著性差异,且检出限更低、分析速度更快,对于食品中痕量污染物的残留监测具有应用价值。     

CE‐MS with electrokinetic supercharging and application to determination of neurotransmitters

Electrokinetic supercharging (EKS) is known as one of the most effective online electrophoretic preconcentration techniques, though pairing with it with mass spectrometry has presented challenges. Here, EKS is successfully paired with ESI‐MS/MS to provide a sensitive and robust method for analysis of biogenic amines in biological samples. Injection parameters including electric field strength and the buffer compositions used for the separation and focusing were investigated to achieve suitable resolution, high sensitivity, and compatibility with ESI‐MS. Using EKS, the sensitivity of the method was improved 5000‐fold compared to a conventional hydrodynamic injection with CZE. The separation allowed for baseline resolution of several neurotransmitters within 16 min with LODs down to 10 pM. This method was applied to targeted analysis of seven biogenic amines from rat brain stem and whole Drosophila tissue. This is the first method to use EKS with CE‐ESI‐MS/MS to analyze biological samples.     

Determination of biogenic amines in fish tissues by ion-exchange chromatography with conductivity detection

Some biogenic amines, such as putrescine, cadaverine, spermidine and histamine, have been found to be useful as quality indices for the decomposition of fish, so research on the simultaneous analysis of various biogenic amines in food is of interest and importance. The intake of histamine may cause an allergic intoxication known as "scombroid poisoning" while secondary biogenic amines can potentiate the toxicity of histamine and in addition can react with nitrite to form carcinogenic nitrosamines. A new method for the simultaneous determination of underivatized biogenic amines based on ion-exchange chromatography with conductivity detector has been developed. The proposed method offers a number of advantages over previous pulsed amperometric detection and integrated pulsed amperometric detection methods such as simpler extraction procedure and sharp peaks. Separations were performed on a new low hydrophobic weak cation-exchange analytical column. This technique is simple, rapid and useful for routine checks in repetitive analyses.     

A high-throughput on-line microdialysis-capillary assay for D-serine.

A high-throughput method is described for the analysis of D-serine and other neurotransmitters in tissue homogenates. Analysis is performed by microdialysis-capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection in a sheath flow detection cell. Sample pretreatment is not required as microdialysis sampling excludes proteins and cell fragments. Primary amines are derivatized on-line with o-phthaldialdehyde (OPA) in the presence of beta-mercaptoethanol followed by on-line CE-LIF analysis. Under the separation conditions described here, D-serine is resolved from L-serine and other primary amines commonly found in biological samples. Each separation requires less than 22 s. Eliminating the need for sample pretreatment and performing the high-speed CE analysis on-line significantly reduces the time required for D-serine analysis when compared with traditional methods. This method has been used to quantify D-serine levels in larval tiger salamander retinal homogenates, as well as dopamine, gamma-amino-n-butyric acid (GABA), glutamate and L-aspartate. D-serine release from an intact retina was also detected.     

Integrated on-chip derivatization and electrophoresis for the rapid analysis of biogenic amines

We demonstrate the monolithic integration of a chemical reactor with a capillary electrophoresis device for the rapid and sensitive analysis of biogenic amines. Fluorescein isothiocyanate (FITC) is widely employed for the analysis of amino-group containing analytes. However, the slow reaction kinetics hinders the use of this dye for on-chip labeling applications. Other alternatives are available such as o-phthaldehyde (OPA), however, the inferior photophysical properties and the UV lambdamax present difficulties when using common excitation sources leading to a disparity in sensitivity. Consequently, we present for the first time the use of dichlorotriazine fluorescein (DTAF) as a superior in situ derivatizing agent for biogenic amines in microfluidic devices. The developed microdevice employs both hydrodynamic and electroosmotic flow, facilitating the creation of a polymeric microchip to perform both precolumn derivatization and electrophoretic analysis. The favorable photophysical properties of the DTAF and its fast reaction kinetics provide detection limits down to 1 nM and total analysis times (including on-chip mixing and reaction) of <60 s. The detection limits are two orders of magnitude lower than current limits obtained with both FITC and OPA. The optimized microdevice is also employed to probe biogenic amines in real samples.     

Fluorometric sensing of biogenic amines with aggregation-induced emission-active tetraphenylethenes

A fluorometric sensor for detection and identification of biogenic amines with carboxylic acid modified tetraphenylethenes (TPEs) based on aggregation-induced emission (AIE) is reported. A mixture of the carboxylic acid substituted TPE and biogenic amines displayed a blue emission on aggregation, which serves as a "turn-on" fluorescent sensor for the amines, the degree of fluorescence enhancement being dependent on the amine. The chromic responses were utilized to distinguish the amines. A fluorometric sensor array of three TPEs with carboxylic acid groups was shown to identify accurately 10 different amines, including biogenic amines. The response patterns were systematically classified by using linear discriminant analysis (LDA) with 98% classification accuracy. Additional information on the concentration of histamine in a "tuna fish matrix" as an example was assessed by the further analysis of the fluorescence intensity, demonstrating a test for food freshness and quality.     

Sensitive chiral analysis by CE: an update

A general view of the different strategies used in the last years to enhance the detection sensitivity in chiral analysis by CE is provided in this article. With this purpose and in order to update the previous review by García-Ruiz et al., the articles appeared on this subject from January 2005 to March 2007 are considered. Three were the main strategies employed to increase the detection sensitivity in chiral analysis by CE: (i) the use of off-line sample treatment techniques, (ii) the employment of in-capillary preconcentration techniques based on electrophoretic principles, and (iii) the use of alternative detection systems to the widely employed on-column UV-Vis absorption detection. Combinations of two or three of the above-mentioned strategies gave rise to adequate concentration detection limits up to 10(-10) M enabling enantiomer analysis in a variety of real samples including complex biological matrices.