对酞内酰胺苯甲酰氯柱前衍生反应HPLC法检测痕量芳香胺

建立了一种快速、灵敏检测痕量芳香胺的新方法。对苯胺、邻甲苯胺和间甲苯胺与对酞内酰胺苯甲酰氯（简称ＰＩＢ－Ｃｌ）的衍生反应条件、衍生物色谱分离及定量检测条件等进行了研究。衍生试剂在有机溶剂中与３种芳香胺反应迅速，衍生物用乙腈＋水（４８＋５２）作流动相，在反相色谱系统中得到了良好的分离。３种芳香胺的检出限分别为：苯胺１．５ｐｍｏｌ，邻甲苯胺和间甲苯胺均为２．０ｐｍｏｌ。     

苯甲酰化展青霉素和青霉酸的高效液相色谱紫外吸收测定法

建立了一种快速、灵敏检测痕量展青霉素（ｐａｔｕｌｉｎ）和青霉酸（ｐｅｎｉｃｉｌｌｉｃａｃｉｄ）的新方法。对酞内酰胺苯甲酰氯（４（２－ｐｈｔｈａｌｉｎｕｄｙｌ）ｂｅｎｚｏｙｌｃｈｌｏｒｉｄｅ,简称ＰＩＢ－Ｃｌ］为柱前衍生试剂同展青霉素和青霉酸衍生反应,衍生物用ＯＤＳ柱分离,乙腈－水（４７：５３,Ｖ／Ｖ）作流动相,紫外检测器检测（λ＝３００ｎｍ）。以２倍信噪比计算最低检出限,展青霉素２．０ｐｍｏｌ,青霉酸１０ｐｍｏｌ。     

YPxV1—xO4（0≤x≤1）：Dy^3＋的合成及其光谱性质的研究

本文报道了不同组成的ＹＰｘＶ１－ｘＯ４（０≤ｘ≤１）：Ｄｙ＾３＋的合成和结构。ＹＰｘＶ１－ｘＯ４（０≤ｘ≤１）为四方晶系，晶胞参数随ｘ的增大呈线性减小。基质的Ｓｔｏｋｅｓ位移随ｘ的增大逐渐变大，而激发光谱峰值则向短波方向移动。在ＹＰｘＶ１－ｘＯ４：０．００６Ｄｙ＾３＋体系中，ｘ＞０．４时出现的基质发射是由ＰＯ＾３－４引起的。基质及Ｄｙ＾３＋的发光效率和Ｄｙ＾３＋的发光强度的黄蓝比均与ｘ有关。同时探     

应用反相高效液相色谱法分离L，D－多肽非对映异构体

 应用反相高效液相色谱法（ＲＰ－ＨＰＬＣ）研究了５对Ｌ，Ｄ－多肽非对映异构体在不同条件下的分离情况。通过改换色谱柱、改变流动相的组成及梯度淋洗条件，发现其中的２对（Ｂｏｃ－Ａｌａ－Ｌ，Ｄ－Ａｌａ－ＧｌｙＯＢｚｌ和Ｂｏｃ－Ｇｌｙ－Ｌ，Ｄ－Ａｌａ－ＶａｌＯＢｚｌ）可以得到较好的分离，分离度分别为１．１和１．６，因此这２对Ｌ，Ｄ－多肽非对映异构体可以作为研究接肽反应消旋情况的模型体系。     

应用反相高效液相色谱法分离L，D－多肽非对映异构体

应用反相高效液相色谱法（ＲＰ－ＨＰＬＣ）研究了５对Ｌ，Ｄ－多肽非对映异构体在不同条件下的分离情况。通过改换色谱柱、改变流动相的组成及梯度淋洗条件，发现其中的２对（Ｂｏｃ－Ａｌａ－Ｌ，Ｄ－Ａｌａ－ＧｌｙＯＢｚｌ和Ｂｏｃ－Ｇｌｙ－Ｌ，Ｄ－Ａｌａ－ＶａｌＯＢｚｌ）可以得到较好的分离，分离度分别为１．１和１．６，因此这２对Ｌ，Ｄ－多肽非对映异构体可以作为研究接肽反应消旋情况的模型体系。     

铂－锇共显色衍生配合物的高效液相色谱研究

研究了Ｏｓ（Ⅱ）和４，４’二（二乙氨基）苯硫酮与Ｐｔ（Ⅱ）共显色所衍生的配合物，于ＮｕｃｌｅｏｓｉｌＣ＿８柱上，用含３×１０￣（－３）ｍｏｌ／ＬＤＬ－樟脑－１０－磺酸和０．０２ｍｏｌ／ＬＨＡｃ－ＮａＡｃ（ｐＨ３．５）的乙腈－丙酮－水（７２：５：２３，Ｖ／Ｖ）作流动相（１．０ｍＬ／ｍｉｎ）分离并检测。线性范围为０．２～４．０μｇ／ｍＬＰｔ；检测限为１．０ｎｇＰｔ。此方法已应用于抗癌药物顺铂和卡铂的分析。     

1,4—双（氯甲基）—2—甲氧基—5—壬氧基苯的均聚和共聚研究

以１，４－双（氯甲基）－２，５一二甲基苯（ＢＣＭＤＭＢ）和１，４－双氯甲基－２－甲氧基－５－壬氧基苯（ＢＣＭＭＯＮＯＢ）为单体，采用脱氯化氢法，合成了聚（２，５－二甲基）对亚苯基亚乙烯（ＰＤＭＰＶ）和聚（２－甲氧基－５－壬氧基）对亚苯基亚乙烯（ＰＭＯＮＯＰＶ）；并对ＢＣＭＤＭＢ和ＢＣＭＭＯＮＯＢ的共聚进行了研究。结果表明，适宜的反应条件为：碱与单体的摩尔比为２０∶１，在室温下聚合时间为３０ｈ，碱的ｐＨ＝１４时产率最高。用ＩＲ、１Ｈ－ＮＭＲ、ＵＶ—Ｖｉｓ对聚合物进行了表征。     

THE EXCITED STATES AND VIBRATIONAL FREQUENCIES OF Bli_2~e（e＝0，＋1，－1）CLUSTERS

ＴＨＥＥＸＣＩＴＥＤＳＴＡＴＥＳＡＮＤＶＩＢＲＡＴＩＯＮＡＬＦＲＥＱＵＥＮＣＩＥＳＯＦＢｌｉ：（ｅ＝０，＋１，－１）ＣＬＵＳＴＥＲＳＴＨＥＥＸＣＩＴＥＤＳＴＡＴＥＳＡＮＤＶＩＢＲＡＴＩＯＮＡＬＦＲＥＱＵＥＮＣＩＥＳＯＦＢｌｉ：（ｅ＝０，＋１，－１）Ｃ...     

反相离子对色谱法测定硫代硫酸根和碘离子的研究

首次利用Ｓ２Ｏ２－３和Ｉ－与Ｈｇ－ＥＤＴＡ二元络合物通过柱前衍生形成ＥＤＴＡ－Ｈｇ－Ｓ２Ｏ３和ＥＤＴＡ－Ｈｇ－Ｉ两种三元络合物的方法,实现了对Ｓ２Ｏ２－３和Ｉ－的间接反相离子对色谱分离和紫外检测。在ＺｏｒｂａｘＯＤＳ柱上,用甲醇∶水＝２３∶７７作流动相,内含对离子ＴＢＡ＋３．０ｍｍｏｌ／Ｌ,ＥＤＴＡ１．０ｍｍｏｌ／Ｌ,ＮａＮＯ３２．０ｍｍｏｌ／Ｌ和缓冲剂ＫＨ２ＰＯ４－Ｎａ２ＨＰＯ４（ｐＨ７．０）,紫外２５４ｎｍ检测。Ｓ２Ｏ２－３和Ｉ－的最小检出限分别为６１．１ｎｇ和３７．６ｎｇ。方法简便,选择性好。     

邻苯二甲醛柱前衍生反相高效液相色谱法测定人和小鼠血浆中的游 …

以邻苯二甲醛（ＯＰＡ）３－巯基丙酸（３－ＭＰＡ）为衍生试剂，手动柱前衍生，ＯＤＳ（十八基哇烷）柱分离；以磷酸盐缓冲液（ＰＨ７．２）配制流动相，二元一级性梯度洗脱，紫外３４０ｎｍ检测，在４０ｍｉｎ内分离测定了人和小鼠血浆中２１种游离氨基酸的含量。方法准确可靠。２１种氨基酸保留时间和峰面积的相对标准偏差分别为０．０９－０．３８％和１．５－４．９％，氨基酸的进样量为０．１－１．６ｎｍｏｌ时，峰面积与进样     

Determination of deoxynivalenol (vomitoxin) by high-performance liquid chromatography with electrochemical detection

A rapid method for the analysis of deoxynivalenol (DON) was developed using high-performance liquid chromatography (HPLC) with reductive electrochemical detection (ED). Deoxynivalenol produced by Fusarium roseum growing on solid cornmeal and rice substrates and from naturally contaminated wheat was extracted and quantitated via ED. DON levels in wheat were verified by gas chromatography and structurally confirmed by mass spectrometry. DON was optimally resolved by HPLC employing a radially compressed octadecylsilane column and a mobile phase of deoxygenated methanol-40 mM borate buffer (35:65) at a flow-rate of 1.0 ml/min. Under these conditions DON exhibited an average retention time of 3.6 min. Reductive ED (-1.4 V) allowed a 12-fold increase in sensitivity and greater selectivity than classical UV absorption at 224 nm. A detection limit for DON of 25 pg/microliter was achieved under these conditions. The determination of DON in crude grain extracts was hindered by extractable interfering substances, whereas ED was more functional-group selective (i.e. reduction of the carbonyl moiety). ED permits a direct quantitation of DON from crude grain extracts and may facilitate the determination of this agent and associated metabolites in biological samples.     

Comparison of four C18 columns for the liquid chromatographic determination of deoxynivalenol in naturally contaminated wheat

Three long and 1 short reversed-phase C18 columns were compared for separation of deoxynivalenol (DON) in extracts of naturally contaminated wheat samples using liquid chromatography with ultraviolet detection and liquid chromatography/mass spectrometry (LC/MS). Among the 3 long columns used, a Symmetry C18 column with an isocratic solvent mixture of water-acetonitrile-methanol (90 + 5 + 5, v/v/v) gave the best separation for DON without interferences from other compounds in the wheat extracts. The Symmetry short (75 mm) column was comparable with the long column (250 mm) in resolving DON but significantly reduced retention time (i.e., 5.8 versus 16.3 min). Increasing the column temperature from 25 to 45 degrees C resulted in a further reduction in retention time. Identity of DON in the wheat extracts and standard solutions was confirmed by LC/MS in the positive ion mode, whereby DON appeared with an (M+1)+ ion at a mass-to-charge ratio of 297 plus fragment ions associated with loss of water and/or a 30 atomic mass unit (amu) CH2O fragment. The Symmetry short column was also capable of separating a mixture of the mycotoxins DON, 15-acetyl-DON, nivalenol, and zearalenone by use of a combination of an isocratic and gradient solvent system. The overall method showed high precision, exhibiting a relative standard deviation of 4.8%, limit of detection of 50 ng/g, and limit of quantitation of 165 ng/g. It was significantly correlated with enzyme-linked immunosorbent assay analysis, indicating its appropriateness for safety and quality assurance of wheat and related grains.     

Use of a multifunctional column for the determination of deoxynivalenol in grains, grain products, and processed foods

Deoxynivalenol (DON), also known as vomitoxin, belongs to a class of naturally occurring mycotoxins produced by Fusarium spp. DON, 12, 13-epoxy-3,7 trihydroxytrichothec-9-en-8-one, is one of the most frequently detected mycotoxins in agricultural commodities worldwide. A method consisting of extraction, filtration, column cleanup, and RP-HPLC-UV separation and quantitation was validated for the determination of DON in grains (rice and barley), grain products (whole wheat flour, white flour, wheat germ, and wheat bran), and processed foods (bread, breakfast cereals, and pretzels). A 25 g test portion was extracted with 100 mL acetonitrile-water (84 + 16, v/v). After blending for 3 min, the supernatant was applied to a multifunctional column (MycoSep 225). The purified filtrate (2 mL) was evaporated to dryness and redissolved in the mobile phase. The toxins were then subjected to RP-HPLC-UV analysis. The accuracy and repeatability characteristics of the method were determined. Recoveries of DON added at levels ranging from 0.5 to 1.5 microg/g for all test matrixes were from 75 to 98%. SD and RSD(r) ranged from 0.7 to 11.6% and 0.9 to 12.7%, respectively. Within-laboratory HorRat values were from 0.1 to 0.7 for all matrixes analyzed. The method was found to meet AOAC method performance criteria for grains, grain products, and processed foods. The identity of DON in naturally contaminated test sample extracts was confirmed by HPLC/MS/MS analysis.     

Determination of deoxynivalenol in whole wheat flour and wheat bran

A liquid chromatographic (LC) method was developed for determining deoxynivalenol (DON) in whole wheat flour and wheat bran. A 15 g test sample was extracted with acetonitrile-water (84 + 16, v/v) and applied to a Romer MycoSep cleanup column. The eluate was dried and then reconstituted in a 0.1 M phosphate buffer, pH 7.0, and applied to a Vicam DONtest-LC cleanup column. The methanol eluate was chromatographed with a methanol-water (17 + 83, v/v) mobile phase on a C18 column with UV detection at 220 nm. Five replicates at each of 5 fortification levels (0.25, 0.50, 1.0, 2.0, and 4.0 ppm), plus 5 controls, were determined for both whole wheat flour and wheat bran. For flour, the average recoveries were 72.2-91.5% with relative standard deviations (RSDs) of 4.9-18.4%. The intra-assay flour recovery was 82.4% with 9.8% RSD. A 5 replicate sample of naturally incurred wheat had an average of 1.1 ppm DON with 6.7% RSD. For bran, average recoveries of fortified samples were 69.5-99.7% with RSDs of 1.7-18.8%. The intra-assay bran recovery was 81.5% with 8.9% RSD. The limit of detection (about 3x noise) for the method is 0.05 ppm; the correlation coefficient (linearity) was >0.9995. The DON peak was clearly identified and easily integrated in the chromatograms.     

Purification of deoxynivalenol from Fusarium graminearum rice culture and mouldy corn by high-speed counter-current chromatography

Deoxynivalenol (DON) is a mycotoxin produced by several Fusarium species and is toxic to a wide range of organisms, including human beings and livestock. To produce large amounts of pure DON for research purposes, a novel method using high-speed counter-current chromatography (HSCCC) was developed. Rice cultured with Fusarium graminearum and field mouldy corn infected by F. graminearum were extracted with methanol and found to contain 1.16 and 1.30 mg DON/g, respectively. The extracts were concentrated and then separated using a biphasic solvent system consisting of ethyl acetate-water (1:1, v/v). Collected fractions were analyzed by high-performance liquid chromatography (HPLC) and identified by congruent retention time and UV/vis spectrum and mass spectrometric data. Fractions containing DON were combined and freeze-dried. This method produced 116 mg and 65 mg DON with a purity of greater than 94.9% from 200 g of the rice culture and the mouldy corn, respectively. The HSCCC method had a recovery rate of DON at 88% from the crude extracts of both samples. This one-step purification method provided a simple and effective tool for obtaining a large amount of DON, an essential material for studies related to toxicology and detoxification of this mycotoxin.     

The use of supercritical fluid extraction for the determination of 4-deoxynivalenol in grains: The effect of the sample clean-up and analytical methods on quantitative results

Summary Deoxynivalenol (DON) is one of the trichothecene mycotoxins produced byFusarium molds in grains. Polar cosolvents in supercritical carbon dioxide (SC-CO₂) are needed to extract and isolate the polar DON moiety. This unfortunately results in the extraction of many interfering compounds from the grains into the extracts obtained by supercritical fluid extraction (SFE). Analysis of DON by high performance liquid chromatography (HPLC) using ultraviolet detection (UV) does not provide a specific detection method, although specific detection of DON can be enhanced by using purification steps after SFE. Alternatively, combining SFE with an immunoaffinity method can improve detection specificity and sample cleanup. In this study, SFE was employed to determine DON in grains and cereal products. The effectiveness of the SFE method was compared with two different solvent extraction methods. The extracted DON was quantitatively determined by HPLC-UV using external standardization or competitive enzymelinked immunosorbent assay (ELISA). In some cases, extracts were purified prior to quantitative analysis of the DON by using solvent partitioning, and/or solid phase extraction, or immunoaffinity columns. Therefore, this paper describes the analysis of DON in cereals using different extraction, cleanup and analysis methods. Names are necessary to report factually on available data: however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the products to the exclusion of others that may also be suitable.     

Water-based slow injection ultrasound-assisted emulsification microextraction for the determination of deoxynivalenol and de-epoxy-deoxynivalenol in maize and pork samples

A novel water-based slow injection ultrasound-assisted emulsification microextraction (SI-USAEME) method followed by ultra-high performance liquid chromatography-tandem mass spectrometry analysis was developed for the rapid pretreatment and determination of deoxynivalenol (DON) and its metabolite, de-epoxy-deoxynivalenol (DOM-1), in maize and pork samples. After optimization, the method recoveries for DON and DOM-1 ranged from 73 to 85 % with intraday and interday variations less than 9.4 and 9.2 %, respectively. The limits of detection for DON were 4.2 μg?kg^?1 in maize and 6.2 and 5.9 μg?kg^?1 for DON and DOM-1, respectively, in pork. In addition, an immunoaffinity column (IAC) was prepared. A study comparing the IAC cleanup method, the solid-phase extraction (SPE) cleanup method, and the proposed SI-USAEME method was presented. The water-based SI-USAEME method could become a simple, low-cost alternative to the conventional IAC and SPE method. The method was successfully applied to the analysis of commercial maize and pork products.     

Enzyme-linked immunosorbent assay in analysis of deoxynivalenol: investigation of the impact of sample matrix on results accuracy

Enzyme-linked immunosorbent assay (ELISA) represents a bioanalytical strategy frequently used for rapid screening of mycotoxin deoxynivalenol (DON) in cereals and derived products. Due to a considerable affinity of some anti-DON antibodies to structurally similar DON metabolites, such as DON-3-glucoside (DON-3-Glc) and 3-acetyl-DON (3-ADON), a significant overestimation of DON concentrations may occur. A validation study of six commercial DON-dedicated ELISA kits, namely Ridascreen DON, Ridascreen FAST, DON, DON EIA, AgraQuant DON Assay, Veratox 5/5, and Veratox HS was carried out on wheat, barley, and malt matrices. Performance characteristics of all tested ELISAs were determined using aqueous solutions of DON, DON-3-Glc, and 3-ADON analytical standards, further with extracts of artificially spiked blank cereals, and finally with matrix-matched standards of all three compounds. In the final phase, the accuracy of data was assessed through a comparison of DON concentrations determined by particular ELISAs and reference ultra-high-performance liquid chromatography–tandem mass spectrometry method. For this purpose, both quality control materials and a comprehensive set of naturally and artificially contaminated samples of wheat, barley, and malt were analyzed. High cross-reactivities were proved for both DON-3-Glc and 3-ADON in the majority of examined assays, and moreover, a considerable contribution of some matrix components to overestimation of DON results was confirmed.     

Feasibility study for the production of certified calibrants for the determination of deoxynivalenol and other B-trichothecenes: intercomparison study

Thirteen European laboratories experienced in the analysis of mycotoxins participated in an intercomparison study within a European Commission-funded project. Goals of the study were to check the fitness for purpose of a small batch of gravimetrically prepared calibrants; to compare individually prepared calibrants with common calibrants; to check the feasibility of toxin mixtures as calibrant solutions; and to give recommendations on the production of future certified reference materials (CRMs) with regard to the nature of the calibrant and the means of certification. Each laboratory received ampules of each common calibrant containing single toxins [solution containing either deoxynivalenol (DON), 3-acetyl-DON (3-Ac-DON), nivalenol (NIV), or 15-acetyl-DON (15-Ac-DON)] and 3 ampules of toxin-mixture (solutions of DON + 3-Ac-DON + NIV in acetonitrile) of known concentrations (about 20 microg/mL). Ampules with single toxins (solution containing either DON, 3-Ac-DON, NIV, or 15-Ac-DON) and a toxin-mixture (solutions of DON + 3-Ac-DON + NIV in acetonitrile) of unknown concentrations were distributed to the participants for quantification. The participating laboratories used mainly high-performance liquid chromatography (HPLC)-diode array detection UV for DON, 3-Ac-DON, NIV, and 15-Ac-DON; gas chromatography-electron capture detection (GC-ECD) and GC-mass spectrometry methods were used sparingly. Linear calibration curves were achieved by >90% of the participants. Relative between-day variation (RSDr) of 26% of the laboratories was greater than the target value of 5% for HPLC, and RSDr of 32% of the laboratories was greater than the desired value of 10% for GC. Relative between-laboratory variation (RSDR) of the GC results obtained with single common calibrants was greater than the target value of 16% for all laboratories. RSDR of the HPLC results for the common unknown single toxin solutions was less than the target value of 8% except for 15-Ac-DON. Generally, better recoveries were observed from common calibrants (102% for mix calibrants and 98% for single calibrants) than from individually prepared calibrants (95%). This international comparison study clearly showed the high scattering of results in the analysis of type-B trichothecenes, particularly when GC was used. Obviously, this intercomparison study was not suited for the certification of B-trichothecenes. A certification of the proposed calibrant material was therefore recommended on the basis of its gravimetrical preparation.     

Determination of type A and type B trichothecenes in paprika and chili pepper using LC-triple quadrupole-MS and GC-ECD

There is a need to develop sensitive and accurate analytical methods for determining deoxynivalenol (DON), HT-2 toxin and T-2 toxin in paprika to properly assess the relevant risk of human exposure. An optimized analytical method for determination of HT-2 toxin and T-2 toxin using capillary gas chromatography with electron capture detection and another method for determination of DON by liquid chromatography-mass spectrometry in paprika was developed. The method for determination of HT-2 toxin and T-2 toxin that gave the best recoveries involved extraction of the sample with acetonitrile-water (84:16, v/v), clean-up by solid-phase extraction on a cartridge made of different sorbent materials followed by a further clean-up in immunoaffinity column that was specific for the two toxins. The solvent was changed and the eluate was derivatized with pentafluoropropionic anhydride and injected into the GC system. The limits of detection (LOD) for T-2 and HT-2 toxins were 7 and 3 μg/kg, respectively, and the recovery rates for paprika spiked with 1000 μg toxin/kg were 71.1% and 80.1% for HT-2 and T-2 toxins, respectively. For DON determination, the optimized method consisted of extraction with acetonitrile-water (84:16, v/v) solution followed by a solid-phase extraction clean-up process in a cartridge made of different sorbent compounds. After solvent evaporation in N₂ stream, the residue was dissolved and DON was separated and determined by LC-MS/MS. The LOD for this method was 14 μg DON/kg paprika sample and the DON recovery rate was 86.8%.