Analysis of neuroactive amines in fermented beverages using a portable microchip capillary electrophoresis system

A portable microfabricated capillary electrophoresis (CE) instrument is used for the determination of neurologically active biogenic amines, especially tyramine and histamine, in fermented beverages. The target molecules are labeled on their primary amino groups with fluorescamine in a 10-min reaction, and the samples analyzed directly, producing a detailed electropherogram in only 120 s on a microfabricated glass CE device containing 21.4-cm-long separation channels. Tyramine was found mainly in red wines at <1-3.4 mg/L, while the histamine content of these samples ranged from 1.8 to 19 mg/L. The highest levels of histamine (20-40 mg/L) were found in sake. The analysis of samples drawn from grape crush through malolactic fermentation in four varieties of zinfandel red wines revealed that histamine and tyramine are produced during yeast and malolactic fermentation, respectively. Following malolactic fermentation, the histamine content in these samples ranged from 3.3 to 30 mg/L, and the tyramine content ranged from 1.0 to 3.0 mg/L. This highly sensitive and rapid lab-on-a-chip analysis method establishes the feasibility of monitoring neurologically active amine content and potentially other chemically and allergenically important molecules in our food supply.     

Does bottle color protect red wine from photo‐oxidation?

Even if bottled red wines have an extended shelf life, they undergo several chemical changes, and producers are well aware of the importance of the packaging. However, there is a lack of research into the effect of light on their composition. Therefore, the storage conditions of a Sangiovese wines with respect to artificial light exposure (present/absent) and bottle color (transparent, brown, and green) were investigated. Thirty‐five chemical characteristics (physicochemical, UV‐VIS indexes, and volatile compounds) were recorded after 6 months of storage. Light exposure caused significant differences in total SO₂ and a shift from red to yellow/orange color. For wines kept in transparent bottles, total red pigments, total phenol index, monomeric anthocyanins, copigmentation, chemical age, and some volatile compounds showed significant differences, depending on whether it was exposed to light or not. On the contrary, light exposure was found not significant for the wine stored in green and brown bottles, Finally, an overall increase in variability was found for light‐exposed wine in transparent bottles which could be considered, in itself, a measure of lack of quality.     

Reduction of organic matter and trihalomethane formation potential in reclaimed water from treated industrial estate wastewater by coagulation

Raw water from treated industrial estate wastewater in northern Thailand was used in jar-test coagulation experiments with variations of separate alum and ferric chloride dosages from 10 to 80 mg/L at pH conditions ranging from 5 to 6.5. Natural organic matter (NOM) surrogates and trihalomethane formation potential (THMFP) were determined to study their reduction. The obtained results showed that total organic carbon (TOC) were gradually reduced from the average value of about 6.1 mg/L to a level of about 4.0 mg/L by alum and ferric chloride dosages of approximately 40 mg/L. Moreover, dissolved organic carbon (DOC) were reduced from an average value of 5.1 mg/L to a level of about 4.0 mg/L by alum and ferric chloride dosages of approximately 40 mg/L. Specific ultraviolet absorption (SUVA) were decreased from an average value of approximately 4.7 L/mgm to a level of about 2 L/mgm by alum and ferric chloride dosages of approximately 20 mg/L. In addition, chlorine demands at 1 day reaction were the same as those of 7-day demands with a correlation coefficient of 0.98 (n = 10, correlation significant at the 0.01 level). Interestingly, chloroform of approximately 65 and 60% of total THMFP was found as the predominant THMFP species in treated industrial estate wastewater and reclaimed water, respectively, in comparison with other THM species. Maximum THMFP percentage removal of 25 and 28 by using alum and ferric chloride dosages of about 80 mg/L at pH 5.5 and 5 were obtained, respectively, at the examined conditions.     

Sensitive and selective flow injection analysis of hydrogen sulfite/sulfur dioxide by fluorescence detection with and without membrane separation by gas diffusion

Highly sensitive and selective FIA flow injection analysis procedures for the determination of sulfite/hydrogen sulfite/sulfur dioxide were developed on the basis of an in situ-generated o-phthalaldehyde (OPA)/ammonium reagent and fluorescence detection. The highest sensitivity was achieved at an excitation wavelength of 330 nm, an emission wavelength of 390 nm, and at pH 6.5. Sulfite concentrations between 2.5 nM and 5 microM can be determined with relative standard deviations between 10.5 and 1.0% (n = 5, confidence level alpha = 0.05) by utilization of a reagent that contains 0.2 mM OPA and 0.4 M NH4Cl in 50 mM potassium phosphate buffer. A concentration of 0.1 mM sulfite can be selectively detected in the presence of thiosulfate, thioglycolate, tetrathionate, cysteine, and ascorbate. The fluorometric sulfite detection was combined with a membrane gas diffusion step to improve the selectivity with respect to nonvolatile fluorescing substances. The total sulfite content can be quantitatively separated as sulfur dioxide into an acceptor solution before its flow detection. Between 40 nM and 0.1 mM sulfite can be determined. After 1,000-fold dilution, the total sulfite content can be determined in white and red wines.     

GC-MS法测定葡萄酒中环己基氨基磺酸钠

目的:建立准确、快速测定葡萄酒中环己基氨基磺酸钠的气相色谱-质谱检测方法。方法:样品经去酒精,调pH,在酸性条件下与亚硝酸钠反应,生成衍生产物,通过HP-5 MS柱分离,质谱定性定量。结果:甜蜜素在0.5mg/kg-200mg/kg范围内呈良好线性,方法回收率在93.0%～107.6%范围内,相对标准偏差小于4%。结论:本法样品处理简单,方法精密度高,准确性好,定性准确,适合葡萄酒中甜蜜素的定量定性分析测试。     

Rapid measurement of methyl cellulose precipitable tannins using ultraviolet spectroscopy with chemometrics: application to red wine and inter-laboratory calibration transfer

Information relating to tannin concentration in grapes and wine is not currently available simply and rapidly enough to inform decision-making by grape growers, winemakers, and wine researchers. Spectroscopy and chemometrics have been implemented for the analysis of critical grape and wine parameters and offer a possible solution for rapid tannin analysis. We report here the development and validation of an ultraviolet (UV) spectral calibration for the prediction of tannin concentration in red wines. Such spectral calibrations reduce the time and resource requirements involved in measuring tannins. A diverse calibration set (n = 204) was prepared with samples of Australian wines of five varieties (Cabernet Sauvignon, Shiraz, Merlot, Pinot Noir, and Durif), from regions spanning the wine grape growing areas of Australia, with varying climate and soils, and with vintages ranging from 1991 to 2007. The relationship between tannin measured by the methyl cellulose precipitation (MCP) reference method at 280 nm and tannin predicted with a multiple linear regression (MLR) calibration, using ultraviolet (UV) absorbance at 250, 270, 280, 290, and 315 nm, was strong (r(2)val = 0.92; SECV = 0.20 g/L). An independent validation set (n = 85) was predicted using the MLR algorithm developed with the calibration set and gave confidence in the ability to predict new samples, independent of the samples used to prepare the calibration (r(2)val = 0.94; SEP = 0.18 g/L). The MLR algorithm could also predict tannin in fermenting wines (r(2)val = 0.76; SEP = 0.18 g/L), but worked best from the second day of ferment on. This study also explored instrument-to-instrument transfer of a spectral calibration for MCP tannin. After slope and bias adjustments of the calibration, efficient calibration transfer to other laboratories was clearly demonstrated, with all instruments in the study effectively giving identical results on a transfer set.     

糖渍处理对玫瑰花醇提物自由基清除活性的影响

目的研究糖渍处理对玫瑰花提取物自由基清除活性的影响,以期为糖渍技术在玫瑰花加工及贮藏领域的应用与发展提供理论指导。方法通过福林酚比色法和三氯化铝比色法分别测定玫瑰花提取物中的总酚和总黄酮含量;以葡萄糖和蔗糖为糖渍剂,对玫瑰花提取物进行糖渍;分别以ABTS和DPPH自由基为测试对象,分析糖渍处理过程中玫瑰花提取物自由基清除能力的变化;通过高相液相色谱-质谱联用(HPLC-MS)技术,初步分析糖渍处理前后玫瑰花提取物中花色苷类物质种类和含量的变化。结果玫瑰花提取物具有较高的以没食子酸计的总酚含量((379±1.8)mg/g)和以芦丁计的总黄酮含量((153±7.2)mg/g);糖渍处理能显著提高玫瑰花提取物的自由基清除活性;经HPLC-MS分析发现,糖渍处理对玫瑰花提取物中花色苷的种类和含量有明显的影响。结论糖渍处理能够通过改变玫瑰花提取物中花色苷的种类和含量进而影响其自由基清除活性。     

Investigation on the rapid degradation of congo red catalyzed by activated carbon powder under microwave irradiation

Azo dyestuff-congo red in aqueous solution can be degraded rapidly under microwave irradiation in the presence of activated carbon powder. The results showed that the degradation ratio could reach 87.79% for 25 mL total volume with 50mg/L congo red and 2.0 g/L activated carbon powder under 1.5 min microwave irradiation. Furthermore, within the same irradiation time, congo red could be degraded fully by increasing addition amount (e.g. 3.6g/L) of activated carbon powder and the degradation ratio was up to 96.49%. Otherwise, with the same addition amount, congo red also could be degraded completely by prolonging irradiation time (e.g. 2.5 min) and the degradation ratio was up to 97.88%. In addition, the influences of microwave irradiation time, initial concentration of congo red, addition amount and used times of activated carbon powder as well as solution acidity on the degradation were discussed in details adopting UV-vis spectra, FT-IR spectra, ion chromatography, high phase liquid chromatography (HPLC) and TOC analysis technologies. Here, the method using activated carbon powder as catalyst under microwave irradiation shows many advantages including high degradation ratios, short reaction time, low costs, no intermediates and no secondary pollution. Therefore, it may be fit for dealing with various azo dyestuff wastewaters on a large scale.     

Treatability studies with granular activated carbon (GAC) and sequencing batch reactor (SBR) system for textile wastewater containing direct dyes

The GAC-SBR efficiency was decreased with the increase of dyestuff concentration or the decrease of bio-sludge concentration. The system showed the highest removal efficiency with synthetic textile wastewater (STWW) containing 40 mg/L direct red 23 or direct blue 201 under MLSS of 3,000 mg/L and hydraulic retention time (HRT) of 7.5 days. But, the effluent NO(3)(-) was higher than that of the influent. Direct red 23 was more effective than direct blue 201 to repress the GAC-SBR system efficiency. The dyes removal efficiency of the system with STWW containing direct red 23 was reduced by 30% with the increase of direct red 23 from 40 mg/L to 160 mg/L. The system with raw textile wastewater (TWW) showed quite low BOD(5) TKN and dye removal efficiencies of only 64.7+/-4.9% and 50.2+/-6.9%, respectively. But its' efficiencies could be increased by adding carbon sources (BOD(5)). The dye removal efficiency with TWW was increased by 30% and 20% by adding glucose (TWW+glucose) or Thai rice noodle wastewater (TWW+TRNWW), respectively. SRT of the systems were 28+/-1 days and 31+/-2 days with TWW+glucose and TWW+TRNWW, respectively.     

生活用水含氯量的测定

本文介绍了对福州市西区供水终端含氧量连续一个月的监测结果。测得的平均总氯浓度和游离氯浓度分别为0.43mg/L和0.28mg/L。结果表明同时期内这样的供水在管网内停留一夜后其总氯浓度和游离氯浓度分别可降为0.18mg/L和0.08mg/L。     

Direct quantification of lycopene in products derived from thermally processed tomatoes: optothermal window as a selective, sensitive, and accurate analytical method without the need for preparatory steps

The concept of the optothermal window (OW) is proposed as a reliable analytical tool to rapidly determine the concentration of lycopene in a large variety of commercial tomato products in an extremely simple way (the determination is achieved without the need for pretreatment of the sample). The OW is a relative technique as the information is deduced from the calibration curve that relates the OW data (i.e., the product of the absorption coefficient beta and the thermal diffusion length micro) with the lycopene concentration obtained from spectrophotometric measurements. The accuracy of the method has been ascertained with a high correlation coefficient (R = 0.98) between the OW data and results acquired from the same samples by means of the conventional extraction spectrophotometric method. The intrinsic precision of the OW method is quite high (better than 1%), whereas the repeatability of the determination (RSD = 0.4-9.5%, n= 3-10) is comparable to that of spectrophotometry.     

Application of Box-Wilson experimental design method for 2,4-dinitrotoluene treatment in a sequential anaerobic migrating blanket reactor (AMBR)/aerobic completely stirred tank reactor (CSTR) system

A sequential aerobic completely stirred tank reactor (CSTR) following the anaerobic migrating blanket reactor (AMBR) was used to treat a synthetic wastewater containing 2,4-dinitrotoluene (2,4-DNT). A Box-Wilson statistical experiment design was used to determine the effects of 2,4-DNT and the hydraulic retention times (HRTs) on 2,4-DNT and COD removal efficiencies in the AMBR reactor. The 2,4-DNT concentrations in the feed (0-280 mg/L) and the HRT (0.5-10 days) were considered as the independent variables while the 2,4-DNT and chemical oxygen demand (COD) removal efficiencies, total and methane gas productions, methane gas percentage, pH, total volatile fatty acid (TVFA) and total volatile fatty acid/bicarbonate alkalinity (TVFA/Bic.Alk.) ratio were considered as the objective functions in the Box-Wilson statistical experiment design in the AMBR. The predicted data for the parameters given above were determined from the response functions by regression analysis of the experimental data and exhibited excellent agreement with the experimental results. The optimum HRT which gave the maximum COD (97.00%) and 2,4-DNT removal (99.90%) efficiencies was between 5 and 10 days at influent 2,4-DNT concentrations 1-280 mg/L in the AMBR. The aerobic CSTR was used for removals of residual COD remaining from the AMBR, and for metabolites of 2,4-DNT. The maximum COD removal efficiency was 99% at an HRT of 1.89 days at a 2,4-DNT concentration of 239 mg/L in the aerobic CSTR. It was found that 280 mg/L 2,4-DNT transformed to 2,4-diaminotoluene (2,4-DAT) via 2-amino-4-nitrotoluene (2-A-4-NT) and 4-amino-2-nitrotoluene (4-A-2-NT) in the AMBR. The maximum 2,4-DAT removal was 82% at an HRT of 8.61 days in the aerobic CSTR. The maximum total COD and 2,4-DNT removal efficiencies were 99.00% and 99.99%, respectively, at an influent 2,4-DNT concentration of 239 mg/L and at 1.89 days of HRT in the sequential AMBR/CSTR.     

Electrolytic treatment of Standard Malaysian Rubber process wastewater

A new method of Standard Malaysian Rubber (SMR) process wastewater treatment was developed based on in situ hypochlorous acid generation. The hypochlorous acid was generated in an undivided electrolytic cell consisting of two sets of graphite as anode and stainless sheets as cathode. The generated hypochlorous acid served as an oxidizing agent to destroy the organic matter present in the SMR wastewater. For an influent COD concentration of 2960 mg/L at an initial pH 4.5+/-0.1, current density 74.5 mA/cm(2), sodium chloride content 3% and electrolysis period of 75 min, resulted in the following residual values pH 7.5, COD 87 mg/L, BOD(5) 60 mg/L, TOC 65 mg/L, total chlorine 146 mg/L, turbidity 7 NTU and temperature 48 degrees C, respectively. In the case of 2% sodium chloride as an electrolyte for the above said operating condition resulted in the following values namely: pH 7.2, COD 165 mg/L, BOD(5) 105 mg/L, TOC 120 mg/L, total chlorine 120 mg/L, turbidity 27 NTU and temperature 53 degrees C, respectively. The energy requirement were found to be 30 and 46 Wh/L, while treating 24 L of SMR wastewater at 2 and 3% sodium chloride concentration at a current density 74.5 mA/cm(2). The observed energy difference was due to the improved conductivity at high sodium chloride content.     

Spot diffusing angle diversity MC-CDMA optical wireless system

Multi-carrier code division multiple access (MC-CDMA) combines some of the desirable features of orthogonal frequency-division multiplexing (OFDM) and CDMA in that it offers multi-user capabilities at a reduced channel rate. The authors report the analysis of a MC-CDMA system over the bandlimited optical wireless (OW) channel. Furthermore, the authors evaluate the performance when a line strip multibeam system (LSMS) is used in conjunction with an angle diversity receiver in the OW MC-CDMA system. The results indicate that at a bit error rate of 10^-4 a 7 and 10 dB signal-to-noise ratio (SNR) improvements are obtained through the use of MC-CDMA in a 4-user system when compared to a single-user OW on?off keying system and a 4-user OW CDMA system, respectively. This improvement is obtained by enabling multi-user communication. The performance degrades gradually with increase in the number of users. The use of LSMS and angle diversity offers a more uniform SNR over a given indoor geometry compared to a conventional diffuse OW system (CDS). Results are reported for an angle diversity LSMS MC-CDMA system and are compared to the CDS MC-CDMA system.     

九曲溪水体中的微量元素Al分子荧光法测定

本文通过分子荧光法对九曲溪水体中的微量元素Al进行测定。研究结果表明:分子荧光法的变异系数在5%以内,回收率在97%-103%之间。均达到河水水质理化检验方法要求。九曲溪水体中Al的含量随着人类活动的加强而升高。人类活动相对集中的地方:武夷宫、星村管辖区及玉女峰处水体Al的含量分别为7.639mg/L、9.796mg/L和4.952mg/L。分别是人类活动较少地方水样Al含量2.349mg/L的3.25倍、4.17倍和2.11倍。合理保护九曲溪水资源,应严格控制旅游人数和开放时间等。     

光催化降解玫瑰红的机理研究

以玫瑰红作为研究机理的目标物，在紫外灯的照射和二氧化钛作催化剂的实验条件下，用重铬酸钾法测定化学需氧量，Apollo 9000型TOC测定仪测TOC，UV-VIS8500型紫外-可见分光光度计测定样品的色度，研究光催化降解机理。结果表明：玫瑰红染料的脱色过程与总有机碳TOC、化学需氧量COD的去除过程是不同步的。在玫瑰红的降解过程中，强氧化自由基首先进攻共轭结构．反应初期主要是脱色过程，TOC在没有很大的变化，生成了无色而又相对稳定的中间产物。反应后期是各芳烃中间产物的开环过程，最终完全降解为无机小分子。     

Amperometric determination of total cholesterol at gold electrodes covalently modified with cholesterol oxidase and cholesterol esterase with use of thionin as an electron mediator

Immobilization of cholesterol oxidase (EC 1.1.3.6) (ChOx) on a gold electrode was attempted by cross-linking using glutaraldehyde between ChOx molecules and a self-assembled monolayer of 2-aminoethanethiolate. The resulting electrode (ChOx/Au) exhibits an amperometric response to free cholesterol in the presence of thionin as an electron mediator, and a steady-state response is obtained approximately 60 s after injection of cholesterol into the electrolyte solution. Coimmobilization of cholesterol esterase (EC 3.1.1.13) (ChE) and ChOx (ChE/ChOx/Au) allows the amperometric determination of both esterified cholesterol and free cholesterol. Cyclic voltammetry of the ChE/ChOx/Au and the dependence of the amperometric response to cholesterol on the concentration of thionin suggest that thionin is encapsulated in the enzyme film on the electrode surface. Apparent Michaelis constants of the ChOx/Au and the ChE/ChOx/Au electrodes suggest that the amperometric response was controlled by penetration of the reaction substrate into the films of the enzyme(s). The concentration of total (free and esterified) cholesterol in human serum samples, determined by using the techniques developed in the present study, is in good agreement with that determined by the well-established technique using colorimetry.     

Evaluation of the treatment of chromite ore processing residue by ferrous sulfate and asphalt

The effectiveness of the treatment of chromite ore processing residue (COPR) with ferrous sulfate and encapsulation into asphalt were explored separately and in combination. The asphalt treatment was conducted by mixing COPR or ferrous sulfate pretreated COPR with varying amounts of asphalt. To assess the efficacy of the treatment, the leachability of toxicity characteristic leaching procedure (TCLP) total chromium (Cr) from all treated samples was determined for curing periods up to 16 months. X-ray absorption near edge structure (XANES) analyses were also performed to evaluate the Cr(6+) concentration in the selected samples. The combination treatment of ferrous sulfate and the encapsulation of the treated COPR into asphalt reduced the TCLP total Cr concentration to lower than the regulatory limit of 5mg/L for Cr contaminated soils, after 16 months. However, the Cr concentrations were still higher than the universal treatment standards (UTS) of 0.6 mg/L for hazardous waste. On the other hand, treatment with ferrous sulfate alone or the encapsulation of the COPR in asphalt failed to meet the TCLP total Cr concentration of 5mg/L, after 16 months. XANES analyses results showed that more than 75% Cr(6+) reduction was achieved upon pretreatment with ferrous sulfate.     

Quantitation of resveratrol in red wines by means of stable isotope dilution analysis-ultra-performance liquid chromatography-Quan-time-of-flight mass spectrometry and cross validation

A stable isotope dilution analysis (SIDA) was developed for the quantitative analysis of the health-promoting phytoalexin (E)-resveratrol in red wines by means of UPLC-QuanTOF-MS. After hemisynthetic preparation of (E)-3,5,4'-trihydroxy-2,4,6-trideuterostilbene ((E)-[(2)H(3)]-resveratrol) as the stable isotope labeled internal standard, validation experiments revealed recovery rate of 96.2 ± 0.8% RSD, thus demonstrating the robustness and accuracy of the SIDA-UPLC-QuanTOF-MS method. Repeatability and reproducibility expressed as RSD showed excellent values of 3.0% and 4.0% for (E)-[(2)H(3)]-resveratrol. Cross validation against a SIDA-HPLC-MS/MS analysis using a triple quadrupole mass spectrometer revealed comparable data, but the SIDA-UPLC-QuanTOF-MS was four times faster, thus making the latter method preferential for an accurate high-throughput analysis of wine samples. Comparison of the SIDA data to those obtained by quantitation using a standard addition method and external calibration, respectively, revealed 97.7% and 32.4% of the resveratrol concentration determined by means of SIDA-UPLC-QuanTOF-MS and 101.0% and 12.7% of the resveratrol levels found by using SIDA-HPLC-MS/MS.