韭菜中45种农药的多残留UPLC—MS／MS分析方法

本文建立了超高效液相色谱一串联质谱（UPLC—MS／MS）同时检测韭菜中45种农药的多残留分析方法。样品以乙腈为提取溶剂．采用超声波法提取,PestiCarb／NH：柱净化,乙腈／甲苯（3／1）淋洗,最后用UPLC—MS／MS进行多反应监测分析。结果表明,该方法在0．01～2．0ng范围内线性关系良好,相关系数均大于0．99。平均加标回收率在64．7％～114．4％．相对标准偏差为1．1％～18．1％。方法检出限为0．1～4．7μg／kg,方法定量限为1～10μg／kg。该方法简便、快速、灵敏．适合于韭菜中45种农药的同时测定。     

UPLC–MS/MS同时测定山楂干制品中的8种真菌毒素

建立了一种萃取溶剂少、操作简单、灵敏度高的QuECHERS前处理方法,结合超高效液相色谱-串联质谱实现山楂干制品中黄曲霉毒素(AFB_1、 AFB_2、 AFG_1、 AFG_2)、赭曲霉毒素A (OTA)、交链孢酚(AOH)、交链孢酚单甲醚(AME)、展青霉素(PAT)等8种真菌毒素同步定量分析,并将该方法应用于实际山楂干制品中真菌毒素污染分析,了解其实际污染情况。试验以0.2%甲酸的乙腈溶液为提取剂,采用QuECHERS方法进行前处理,应用超高效液相色谱-质谱联用定量分析8种真菌毒素。结果显示, AFB_1、 AFB_2、 AFG_1、 AFG_2、 OTA、 AOH、 AME等7种真菌毒素在1～50μg/L范围内线性关系良好, PAT在5～50μg/L范围内线性关系良好,相关系数均R2≥0.991。回收率为84.3%～111.5%。将建立的方法应用于17个山楂干制品样品分析,其中AOH和AME检出率分别为100%、 88.2%,含量为1.2～9.0μg/kg,其余6种毒素均未检出。结果表明,建立的QuECHERS方法适用于山楂干制品中多种真菌毒素同步定量分析。     

SPE-UPLC-MS/MS测定葡萄酒中的高氯酸盐

为建立前处理简单、定量准确、灵敏度高的葡萄酒中高氯酸盐的快速测定和分析方法,本研究使用酸化甲醇提取葡萄酒样品,最终选择WAX固相萃取柱前处理净化,亲水性聚丙烯滤膜(GHP)过滤,经Phenyl-Hexyl色谱柱分离,以电喷雾离子源(ESI)在多反应监测(MRM)负离子模式下测定葡萄酒中高氯酸盐。结果表明,该方法的检测时间为12 min,检出限和定量限分别为0.15 μg·L^-1和0.5 μg·L^-1,在1、2、5、10和20 μg·L^-1水平的加标回收率介于94.5%~105%之间,相对标准偏差(RSD)小于3.17%。该方法的建立可为葡萄酒生产企业和相关监管部门提供一定的技术支撑。     

GC/MS在水质检测中的应用

GC/MS已经广泛应用于水质检测中,尤其是对复杂化学组分进行分离鉴定和定量检测。众多的应用研究表明,凭借其特有的高选择性及灵敏度,已成为水质检测重要的技术手段。本文对GC/MS在水质有机污染物检测中的应用做一些介绍。     

用UPLC—MS／MS结合QuEChERS前处理方法快速测定生鲜牛乳中的黄曲霉毒素M1

本文建立了一种以QuEChERS作为前处理方法的生鲜牛乳中黄曲霉毒素M,的快速测定方法。生鲜牛乳以QuEChERS萃取剂提取,QuEChERS净化剂净化并浓缩后,以超高效液相色谱串联质谱法测定。黄曲霉毒素M。在0．1～20．0ixg／kg范围内呈良好的线性关系,日内、日间精密度小于20％,回收率大于80％,检测限为0．05p,g／kg。     

Ecotoxicological characterization of sediment cores from the western Baltic Sea (Mecklenburg Bight) using GC–MS and in vitro biotests

Background, aim, and scope

The Mecklenburg Bight (Western Baltic Sea) near Luebeck, Germany was historically used to dump industrial waste at sea and, thus, sediments in some regions are highly polluted at present. While earlier studies identified hot spots of chemical pollution, little is known about biological activities and impacts on exposed marine organisms. This study aimed to assess the pollution in the Mecklenburg Bight to determine the degree of contamination with sediment-bound polycyclic aromatic hydrocarbons (PAHs) as well as biological activities.

Materials and methods

Sediment cores with a depth of 30 cm were sampled at a dumping site and at a reference site, sliced in distinct layers, freeze-dried, and processed using the accelerated solvent extraction method. Sediment was characterized measuring total organic carbon (TOC) and soot contents. Concentrations of the 16 EPA-PAHs were determined with chemical analysis (gas chromatography–mass spectroscopy) in each sediment slice and referred to the determined TOC content. Further on, in vitro biotests were applied to determine toxic effects of contaminants in the sediment. The acute neutral red retention assay indicated no specific cytotoxic effects. Arylhydrocarbon receptor (AhR)-mediated activities were measured using the mechanism-specific 7-ethoxyresorufin-O-deethylase induction assay. Both biotests were performed with rainbow trout (Oncorhynchus mykiss) liver cells (RTL-W1). Analyzed compound concentrations and biological activities were given in toxicological equivalent concentrations (chem- and bio-TEQs) to determine shares of analyzed EPA-PAHs to the overall activity.

Results

TOC and soot contents indicated a significant alteration through the sediment core at the dumping site. EPA-PAH concentrations were referred to TOC and indicated elevated concentrations at the dumping site. Maximum PAH concentrations (14 to 16 cm depth; 5.44 µg/g TOC) were 300-fold increased at the dumping site, compared to the reference site (4 to 6 cm depth; 0.017 µg/g TOC). Cytotoxicity as determined in the neutral red retention assay was elevated in some layers at the dumping site (maximum in 4 to 6 cm depth; NR₅₀?=?14 mg/ml), but not correlated with TOC or soot contents. Ah receptor agonist activities were clearly elevated in highly PAH-loaded layers at both sites. At the dumping site, maximum activities were determined reflected by a bio-TEQ of 223,000 pg/g (19 to 22 cm), in contrast to a bio-TEQ of 41,000 pg/g (6 to 8 cm) at the reference site. Further on, shares of EPA-PAHs to the overall activity were determined and contributed >40% at the dumping site and between 4% and 17% at the reference site. Chem-TEQs were found to exceed bio-TEQs in a depth of 11 to 22 cm, indicating the presence of Ah receptor antagonistic or inhibitive compounds.

Discussion

Sediments from the dumping site were determined to be highly contaminated and caused toxic effects in depths that are known to be influenced by dumping activities. In contrast, the reference sediment indicated only near to surface layers to be minor contaminated. In comparison with highly polluted sediments from other marine sites, the contamination of the dumping site could be ranked as elevated. Chem-TEQs exceeding bio-TEQs in a depth of 11 to 22 cm seem to be caused by AhR antagonistic compounds in the dumped material. Furthermore, particle-bound PAH concentrations assessed in this study were discussed against freely dissolved concentrations in interstitial water, as determined in a different study with the same sediment core.

Conclusions

Sediments in the inner Mecklenburg Bight could be shown to be highly contaminated, at least with PAHs, causing articulate increased Ah receptor-mediated activities. Marine organisms may be exposed to these contaminants, in particular when inhabiting the sediment.

Recommendations and perspectives

Further research activities should extend the range of chemically analyzed pollutants and applied biotests and endpoints. Monitoring should close the gap between analytical methods in the laboratory and the field to determine possible impacts on organisms at site.     

ASE-HPLC-MS/MS法测定土壤中四环素类抗生素残留

通过优化ASE萃取参数和固相萃取净化条件,建立了土壤中4种四环素类抗生素残留的加速溶剂萃取-液相色谱串联质谱测定方法。选择EDTA-McIlvaine∶甲醇=1∶2(V/V)作为萃取溶剂,应用Oasis-MAX强阴离子交换柱进行样品的富集和净化,乙腈∶0.4%甲酸溶液=22∶78(V/V)条件下进行色谱分离,ESI正离子源和多反应监测模式(MRM)下测定,方法检测限为2.2～3.2μg.kg-1,定量限为22～32μg.kg-1,样品加标回收率在60.1%～103.8%之间,相对标准偏差为2.6%～4.8%。本方法具较高灵敏度和准确度,能满足土壤中μg.kg-1痕量水平4种四环素类抗生素残留测定要求。     

Matrix effects in analysis of β-agonists with LC-MS/MS: influence of analyte concentration, sample source, and SPE type

The synergistic influences of analyte concentration, sample source, and solid-phase extraction (SPE) type on matrix effects in the multiresidue analyses of eight β-agonists with LC-ESI-MS/MS were evaluated. Porcine muscle and liver extracts and urine from diverse sources were purified by strong or mixed-mode cation exchange and molecularly imprinted polymer SPE cartridges, respectively. Three spiked concentrations (2, 10, and 20 ng/mL) of eight β-agonists in the purified matrices and the different sample sources were analyzed. The results show that for most β-agonists there are significant differences in matrix effects between analyte concentrations or sample sources (P < 0.05), whereas there is no significant difference in matrix effects between different SPE cartridges (P > 0.05). Results from main effects testing indicated that analyte concentration was the main effector.     

Phenolic composition of the edible parts (flesh and skin) of Bordô grape (Vitis labrusca) using HPLC-DAD-ESI-MS/MS

The aim of this study was the detailed characterization of the phenolic composition and the determination of the antioxidant activity of the Bord? grape (Vitis labrusca) cultivated in South Brazil. The edible parts of Bord? grapes (flesh and skin) contained 1130 mg/kg of total phenolic compounds (as gallic acid), mainly located in the skins. Anthocyanin content in the skins was high, largely as 3,5-diglucosides (1359 mg/kg, as malvidin 3,5-diglucoside). Total flavonols accounted for 154 μmol/kg, mainly located in the skins and with myricetin 3-glucoside as the principal flavonol in both grape parts. Very low amounts of flavan-3-ol monomers and dimers and low amounts of polymeric proanthocyanidins, with a composition similar to that reported for V. vinifera grape varieties, were found in Bord? grape skins. Hydroxycinnamic acid derivatives mainly derived from caffeic acid and were found in the skins in high amounts, ten times higher than in the flesh (total amount: 483 μmol/kg). Finally, the Bord? grape cultivar can be considered a high resveratrol producer (10.91 mg/kg) and also exhibited a high value of total antioxidant capacity (37.6 ± 1.0 mmol/kg, as Trolox).     

基于nanoUPLC-MS/MS的螺旋藻游离肽组成分析

为了研究螺旋藻中的多肽成分,以钝顶螺旋藻为原料,采用超滤法提取螺旋藻中的游离肽,利用nanoUPLC-MS/MS和PEAKS Studio分析谱图信息,结合NCBI数据库进行比对和从头测序分析,获得游离肽的结构组成和百分含量信息。结果表明,利用数据库比对法和从头测序法,分别得到可信的游离肽4 485个和20 597个,匹配到的蛋白质有1 036种。数据库比对结果中的游离肽主要为七肽到二十一肽,少量为二十一肽以上;从头测序结果中游离肽主要为二肽到十六肽,少量为十六肽以上。数据库比对结果中百分含量最高的游离肽是十肽,为15.95%;从头测序结果中百分含量最高的是五肽,达到24.09%。本研究结果为螺旋藻蛋白资源的进一步开发和利用提供了依据。     

Study on Soil and Pine-Seedling Zn and Mn and Predicting-Model Design

Soils were collected from 2-year (2-y) and 3-year (3-y) old red-pine seedling plots in two tree nurseries, Hayward in the north and Wilson in the southwestern part of Wisconsin State respectively, and equilibrated with 0.01 M Ca(NO₃)₂ for soil solution Zn and Mn (solu-Zn and Mn), and with 0.01 M Ca(NO₃)2+0.005 M EDTA for soil adsorbed Zn and Mn (ad-Zn and Mn). Buffering capacity of soil Zn and Mn (b-Zn and Mn) was obtained from the ratio of ad-Zn and Mn to the solu-Zn and Mn. The concerned traces in pine seedling needles (ndls), stems(sts) and roots (rts) were simultaneously measured.     

微波辅助萃取ICP—MS法测定土壤中有效硼

建立了一种应用微波辅助萃取ICP-MS法测定土壤中有效硼的方法,该方法与NY/T148-1990和NY/T1121.8-2006(姜黄素比色法和甲亚胺比色法)相比,不仅操作简便快速、无污染,而且具有很好的准确度和精密度,其相对标准偏差(RSD)为3.5%,回收率为94.0%～107.3%,方法的检出限为1.13 ng·g-1.     

紫苏挥发油化学成分GC/MS分析及抑菌评价研究

采用水蒸汽蒸馏法分别提取紫苏叶和花中挥发油,运用毛细管气相色谱-质谱联用法结合计算机检索对其挥发油进行化学成分分析,采用面积归一法测定了挥发油中各种成分的相对质量分数,利用抑菌贴片法、MIC法和光电浊度法分别对枯草芽孢杆菌和大肠杆菌进行了抑菌性研究。结果显示,从紫苏叶和花水蒸汽蒸馏所得挥发油中分别检测出12种和10种化合物,其中叶中主要成分为紫苏醛（75.88%）、柠檬烯（3.82%）、石竹烯（9.87%）和法呢烯（3.21%）;花中主要成分为紫苏醛（49.23%）、石竹烯（18.53%）、法呢烯（8.99%）、芳樟醇（11.3%）和姜黄二酮（4.55%）。紫苏精油对两种细菌均有很强的抑制作用,但对枯草芽孢杆菌的抑制能力要明显强于对大肠杆菌的抑制能力。     

Use of pyrolysis/GC–MS combined with thermal analysis to monitor C and N changes in soil organic matter from a Mediterranean fire affected forest

In Mediterranean ecosystems, forest fires are a common phenomenon. They involve the transformation of vegetation and litter, leaving charred residues and so influencing the carbon cycle by changing (a) the amounts of soil organic matter and (b) the proportions within it of pools with differing stability. In addition to affecting C cycles, fires also affect the amounts of N within soil organic matter, and its availability.     

Mycorrhizal colonization and nutrition of wheat and sweet corn grown in manure‐treated and untreated topsoil and subsoil

Dry bean yields (Phaseolus vulgaris L.) were raised to similar levels as the topsoil by manure application to eroded or leveled Portneuf silt loam soil (coarse‐silty mixed mesic Durixerollic Calciorthid). Only soil organic matter and zinc (Zn) content of leaf tissue were correlated with improved yields. Manure application increased mycorrhizal colonization and Zn uptake in pot experiments with dry bean which would explain the increased yields in the field. A field study was conducted to see if similar effects of manure and mycorrhizal colonization could be observed in field grown spring wheat (Triticum aestivum L.) and sweet corn (Zea mays L.). This study was conducted on existing experiments established in the spring of 1991 at the USDA‐ARS farm in Kimberly, Idaho, to study crop rotation/organic matter amendment treatments on exposed subsoils and focused on mycorrhizal colonization as related to topsoils and subsoils treated with conventional fertilizer (untreated) or dairy manure. Mycorrhizal root colonization was higher with untreated than with manure‐treated wheat and sweet corn. Root colonization was also higher in subsoil than in topsoil for wheat, but there were no differences between soils for sweet corn. Shoot Zn and manganese (Mn) concentrations generally increased with increased root colonization for both species (except between soils with corn Mn contents). Wheat shoot potassium (K) concentration was increased by manure application, but the affect declined with time, was the opposite of colonization and was not observed with sweet com. Phosphorus (P), calcium (Ca), magnesium (Mg), iron (Fe), and copper (Cu) concentrations either were not influenced or were erratically affected by mycorrhizal colonization. Yields of wheat were highest for manure‐treated subsoil and topsoil compared to untreated soils. Mycorrhizal colonization was different between conventional and manure‐treated soils and between topsoil and subsoil and these differences increased Zn and Mn uptake, but they did not explain the improvement in wheat yields obtained with manure application.     

蒲公英不同部位抑菌作用及代谢物差异的UPLC-MS/MS分析

为了研究蒲公英不同部位抑菌作用和代谢物成分的差异,本物采用打孔法和超高效液相色谱串联质谱(UPLC-MS/MS)方法,研究了蒲公英根、茎叶和花的水提取物和醇提取物对5种致病菌的抑菌作用,并对不同部位的代谢物成分进行了定性和定量分析。结果表明,蒲公英不同部位初提取物对变形杆菌、嗜根考克氏菌和枯草芽孢杆菌均有抑菌作用,而对大肠杆菌和铜绿假单胞菌均无抑菌作用;醇提法的抑菌效果优于水提法,花提取物的抑菌活性最强,根最弱。蒲公英的不同部位共鉴定出449种代谢物,根、茎叶和花中相对含量最高的物质分别为反油酸(脂类)、γ-亚麻酸(脂类)和木犀草素(黄酮类);且根、茎叶和花中相对含量排名前20的物质中黄酮类分别有0种、3种和8种,表明黄酮类物质可能是蒲公英中的主要抑菌活性物质。正交偏最小二乘法-判别分析(OPLS-DA)结果显示,木犀草素-7-O-葡萄糖苷在花中上调幅度最大,橙皮素C-丙二酰己糖苷为根中特有物质。本研究结果为利用蒲公英不同部位研制和开发新型药物提供了理论依据。     

Detection and quantification of apple adulteration in diluted and sulfited strawberry and raspberry purées using visible and near-infrared spectroscopy

Adulteration of sulfited strawberry and raspberry purées by apple is a commercial problem. Strawberry (n = 31) and raspberry (n = 30) purées were prepared from Irish-grown fruit and adulterated at levels of 10-75% w/w using cooking apples. Visible and near-infrared transflectance spectra were recorded using a 0.1 mm sample thickness. Classification and quantification models were developed using raw and scatter-corrected and/or derivatized spectral data. Classification as pure strawberry or raspberry was attempted using soft independent modeling of class analogy. The best models used spectral data in the wavelength ranges 400-1098 nm (strawberry) and 750-1098 nm (raspberry) and produced total correct classification rates of 75% (strawberry) and 95% (raspberry). Quantification of apple content was performed using partial least-squares regression. Lowest predictive errors obtained were 11.3% (raspberry) and 9.0% (strawberry). These results were obtained using spectral data in the wavelength ranges 400-1880 and 1100-1880 nm, respectively. These results suggest minimum detection levels of apple in soft fruit purées of approximately 25 and 20% w/w for raspberry and strawberry, respectively.     

High-performance liquid chromatography with photodiode array detection (HPLC-DAD)/HPLC-mass spectrometry (MS) profiling of anthocyanins from Andean Mashua Tubers (Tropaeolum tuberosum Ruíz and Pavón) and their contribution to the overall antioxidant activity

Mashua (Tropaeolum tuberosum Ruíz and Pavón), an Andean tuber with high antioxidant activity, has sparked interest because of its traditional medicinal use. In this study, we evaluated the anthocyanin composition for three purple mashua genotypes and their contribution to the overall antioxidant activity of the tuber. Mashua anthocyanins, total phenolics, and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) antioxidant activity ranged from 45.5 to 131.9 mg of cyanidin 3-glucoside equivalents/100 g fresh weight (FW), 174.9 to 275.5 mg of gallic acid equivalents/100 g of FW, and 16.2 to 45.7 micromol of Trolox equivalents/g of FW, respectively. The high-performance liquid chromatography with photodiode array detection (HPLC-DAD) and HPLC-electrospray ionization tandem mass spectrometry (ESI/MS-MS) profiles revealed the presence of 11 different anthocyanins. The two major pigments (56.4-73.0% total area range at 520 nm) were identified as delphinidin 3-glucoside-5-acetylrhamnoside and delphinidin 3-sophoroside-5-acetylrhamnoside. Other pigments were delphinidin 3-glucoside-5-rhamnoside, delphinidin 3-sophoroside-5-rhamnoside, delphinidin 3-glucoside, cyanidin 3-sophoroside, and cyanidin 3-sophoroside-5-rhamnoside. Cyanidin 3-glucoside and cyanidin 3-rutinoside were only found in two genotypes, while pelargonidin 3-sophoroside and pelargonidin 3-sophoroside-5-rhamnoside were only found in the third one. Anthocyanins from mashua were the major contributors to the total ABTS values for only one of the three genotypes, suggesting that other phenolics present are playing a major role in the antioxidant power of mashua tubers. Results from this study provide important information for the Nutraceutical and Functional Food Market for the use of mashua anthocyanins not only as a source of natural colorants but also as a source of phytonutrients.     

用MS Office“查找与替换”功能实现农药数据批处理

针对农药信息平台基础数据存在的三种问题进行了剖析,并基于MS Office的＂查找与替换＂功能,提出了简单易用的操作方案,快速准确地批处理了大量问题数据。     

Speciation and biochemical transformations of sulfur and copper in rice rhizosphere and bulk soil—XANES evidence of sulfur and copper associations

Purpose  

Contamination of heavy metals in soil and its subsequent accumulation along the food chain is a potential risk to human health. Cu speciation in soil–plant system, particularly on the availability to plant roots, has obtained great attention. X-ray absorption near-edge structure spectroscopy (XANES) provides information about the bonding of Cu soil components at the molecular scale. In paddy soils, changes of redox conditions led to microbially mediated sulfur transformation, thus affecting heavy metal behavior. The objective of this work was to investigate how sulfur transformation in a paddy soil affected Cu biogeochemical processes.