QuEChERS-超高效液相色谱-串联质谱法同时快速检测果蔬中35种甲氧基丙烯酸酯类和三唑类杀菌剂的残留量

目的建立超高效液相色谱-串联质谱法同时快速测定水果蔬菜中35种甲氧基丙烯酸酯类和三唑类杀菌剂残留量的分析方法。方法样品用乙腈提取及QuEChERS方法净化,制得含有残留杀菌剂的上清液。采用Waters ACQUITY HSS T3 C_(18)柱(2.1 mm×100 mm, 1.8μm)以0.2%甲酸溶液-乙腈作为流动相进行梯度洗脱,质谱(ESI+)电喷雾正离子模式电离,采用多离子检测模式对35种杀菌剂的定量离子和定性离子进行监测。结果在1.0～50μg/L的浓度范围内35种杀菌剂线性关系良好,相关系数r~2为0.9990～0.9997;在5.0、50、100μg/kg添加水平的回收率为61.8%～125%,方法检出限为0.3～0.5μg/kg,定量限为1.0～1.5μg/kg。结论该方法快速、环境友好、准确、灵敏,适合水果蔬菜甲氧基丙烯酸酯类和三唑类杀菌剂残留的检测。     

QuEChERS-超高效液相色谱-串联质谱法测定蔬菜中9种甲氧基丙烯酸酯类杀菌剂

建立了采用QuEChERS方法提取净化,超高效液相色谱-串联质谱法（UPLC/MS/MS）同时测定蔬菜中的9种甲氧基丙烯酸酯（Z-苯氧菌酯、E-苯氧菌酯、嘧菌酯、肟嘧菌胺、醚菌胺、啶氧菌酯、吡唑醚菌酯、肟菌酯、嘧螨酯）杀菌剂残留量的方法。样品经乙腈提取,采用正交试验验优选N-丙基乙二胺（PSA）和C₁₈以及石墨化炭黑（GCB）净化用量。使用0.05%甲酸水和0.05%甲酸乙腈作为流动相梯度洗脱,目标化合物经岛津Shim-PackC₁₈色谱柱（2.1 mm×50 mm,2 μm）分离,在正离子模式下进行测定。结果表明,9种甲氧基丙烯酸酯类杀菌剂在1～100 ng/mL范围内线性关系良好,决定系数在0.9942～0.9995之间,方法检出限（LOD）为0.05～0.3 μg/kg,定量限（LOQ）为0.2～0.9 μg/kg。在2、10和20 μg/kg三个添加水平下,五种蔬菜的回收率在77.26%～111.73%之间,相对标准偏差在0.46%～6.59%之间。该方法准确、快速、便捷、灵敏度高,能够满足蔬菜中9种甲氧基丙烯酸酯类杀菌剂的痕量检测要求。     

QuEChERS-UPLC-MS/MS法测定热带和亚热带水果中5种三唑类杀菌剂

该实验采用QuEChERS净化-超高效液相色谱-串联质谱法测定石榴、芒果、火龙果的5种三唑类杀菌剂残留。样品10.0 g经改进的QuEChERS方法进行前处理,采用ZORBAX SB-C18色谱柱分离,以4 mmol/L甲酸水溶液和甲醇为流动相进行梯度洗脱。质谱采用电喷雾离子源（ESI）和多反应监测（MRM）模式。5种三唑类杀菌剂的质量浓度为4.0～200.0 μg/L时,线性关系良好,相关系数（R2）＞0.999,定量限（LOQ）为0.15～1.0 μg/kg,石榴、芒果、火龙果中5种三唑类杀菌剂加标回收率分别为87.7%～103.1%、80.5%～93.5%、81.6%～94.7%,相对标准偏差（RSD）（n=6）分别为4.1%～11.2%、3.8%～7.3%、4.3%～10.2%。说明该方法灵敏度及准确度良好,能满足石榴、芒果、火龙果（皮不可食的热带和亚热带水果）中5种三唑类杀菌剂残留检测的要求。     

液相色谱-质谱法测定果蔬中8种甲氧基丙烯酸酯类杀菌剂残留量

建立一种测定果蔬中8种甲氧基丙烯酸酯类杀菌剂农药残留量的液相色谱-质谱检测方法.样品经乙腈提取,固相萃取柱净化,液相色谱分离,选择离子监测-大气压化学电离质谱测定.8种被测物在0.05 mg/L～5 mgL范围内线性关系良好,相关系数大于0.995 3.方法的测定低限为0.01 mg/kg,平均回收率为76.5%～92.5%,重复试验7次,RSD值小于10.2%.     

QuEChERS-UPLC-MS/MS测定果蔬中18 种琥珀酸脱氢酶抑制剂类杀菌剂

建立改进的QuEChERS提取和净化方法，结合超高效液相色谱-串联质谱（ultra-high performance liquid chromatography-tandem mass spectrometry，UPLC-MS/MS）法测定果蔬中18 种琥珀酸脱氢酶抑制剂类杀菌剂。样品经乙腈均质提取，无水硫酸镁及醋酸钠脱水盐析，乙二胺-N-丙基硅烷净化，以乙腈-0.1%甲酸溶液为流动相进行梯度洗脱，采用正负离子同时扫描，多反应监测模式，使18 种目标化合物在C18色谱柱上分离，外标法定量。18 种目标化合物在0.5～200 μg/L范围内线性关系良好，相关系数均大于0.99，方法检出限为0.5～2.0 μg/kg，定量限为1.5～6.0 μg/kg。各种目标化合物在4 种基质中3 个添加水平（10、50 μg/kg和150 μg/kg）下的回收率为83.6%～109.4%，相对标准偏差为1.2%～8.4%（n＝6）。该方法操作简单、净化效果好，适用于果蔬中新型琥珀酸脱氢酶抑制剂类杀菌剂的快速检测。     

QuEChERS-气相色谱-串联质谱法测定番茄中九种甲氧基丙烯酸酯类杀菌剂

建立了采用QuEChERS方法提取净化,气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry,GC-MS/MS)同时测定番茄中9种甲氧基丙烯酸酯(啶氧菌酯、E-苯氧菌酯、Z-苯氧菌酯、嘧螨酯、肟菌酯、醚菌胺、肟嘧菌胺、醚菌酯、嘧菌酯)杀菌剂残留量的方法。样品经乙腈提取,采用正交试验优选N-丙基乙二胺和C18以及石墨化炭黑的净化用量。使用Rtx-5色谱柱程序升温分离,以EI源电离,在多反应监测模式(multiple reaction monitoring,MRM)进行定性分析,用基质匹配校准曲线外标法进行定量分析。9种甲氧基丙烯酸酯类杀菌剂在5～800 ng/m L范围内线性关系良好,相关系数为0.993 9～0.999 5,检出限为0.5～2.5μg/kg,定量限为2～8μg/kg。向番茄样品中分别加入3个不同浓度进行加标回收试验,加标回收率为73.24%～91.38%,相对标准偏差为2.51%～10.18%。该方法准确度高、精密度好、操作简单、成本低廉,满足番茄中9种甲氧基丙烯酸酯类杀菌剂的痕量检测要求。     

亲脂性匹配色谱分离-超高效液相色谱-串联质谱法测定果蔬中21种三唑类杀菌剂

为了提高农药残留的色谱分离效率和降低基质效应,本研究提出亲脂性匹配色谱分离,选取三唑类杀菌剂为研究对象,建立了果蔬中21种三唑类杀菌剂的超高效液相色谱-串联质谱(Ultra performance liquid chromatographytandem mass spectrometry,UPLC-MS/MS)检测方法。样品经乙腈提取,盐析分相,分散固相萃取净化,选用与三唑类杀菌剂具有相近亲脂性的色谱柱进行分离,探究不同亲脂性烷基键合相对基质效应、回收率以及三唑杀菌剂和基质组分色谱分离的影响。结果表明,亲脂性匹配色谱分离能够提高色谱分离效率,改善三唑杀菌剂和基质组分的色谱分离,21种三唑杀菌剂的基质效应为-8.3%～4.7%,在5～250μg/L浓度范围内线性关系良好,决定系数R²≥0.999,平均回收率为91.4%～108.1%,定量限为0.5～3.5μg/kg。该检测方法能够有效降低基质效应,使用溶剂校准曲线进行定量即可获得满意的回收率,显著提高了检测效率,具有简便、准确、灵敏度高等特点,适用于果蔬中三唑杀菌剂的检测。所述亲脂性匹配色谱分离,为农药残留的液相色...     

高效液相色谱-串联质谱法测定蔬菜中13种氨基甲酸酯类农药和杀菌剂残留

目的 建立高效液相色谱-串联质谱法(high performance liquid chromatography-tandem mass spectrometry, HPLC-MS/MS)测定蔬菜中13种氨基甲酸酯类农药和杀菌剂残留量的分析方法。方法 样品经乙腈提取, 分散固相萃取净化后, 采用Waters ACQUITY HSS T3色谱柱(100 mm×2.1 mm, 1.8 μm)分离, 以乙 腈-水(0.05%甲酸)梯度洗脱, 串联质谱测定, 外标法定量。结果 在优化实验条件下, 13种氨基甲酸酯类农药和杀菌剂在0~100 μg/L质量浓度范围内线性良好, 相关系数均大于0.99, 方法的加标回收率为70%~129%。结论 该方法具有样品预处理简单、灵敏度高、分析时间短等优点, 可用于蔬菜中13种氨基甲酸酯类农药和杀菌剂残留的测定。     

QuEChERS-气相色谱/质谱法检测香椿等芽菜类蔬菜中5种酰胺类杀菌剂残留量

目的建立QuEChERS-气相色谱-质谱法定量检测芽菜类蔬菜中的5种酰胺类杀菌剂的含量的分析方法。方法芽菜类蔬菜加乙腈溶剂均质后, QuEChERS提取法进行提取、净化,提取液氮吹至近干,加正己烷溶解、定容至1 mL,气相色谱-质谱仪定量检测。结果乙草胺、甲草胺、灭锈胺、苯酰菌胺和啶酰菌胺浓度在0.02～10.0μg/mL之间,线性关系良好,相关系数(r~2)均大于0.995;检出限分别为0.007、0.006、0.004、0.003、0.003 mg/kg;加标回收率在84.6%～105.2%之间;重复性RSD(n=6)在5.0%以内。结论该方法具有操作简便、回收率好等优点,适用于芽菜类蔬菜中酰胺类杀菌剂的检测。     

液相色谱-串联质谱法快速测定果蔬中16 种新型酰胺类杀菌剂残留量

建立果蔬（白菜、芹菜、草莓和葡萄）中16 种新型酰胺类杀菌剂的液相色谱-串联质谱快速分析方法。样品用乙腈提取和氯化钠盐析分层后,上清液直接用0.1%甲酸溶液稀释10 倍后进行液相色谱-串联质谱分析。采用Acquity BEH C18色谱柱分离,用0.1%甲酸溶液-乙腈作为流动相进行梯度洗脱,电喷雾正离子模式电离,多反应监测模式检测,基质校准外标法定量。各物质峰面积与样品质量浓度在2.5×10－4～0.25 mg/L范围内呈良好的线性关系,线性回归系数不低于0.994 9。在添加量0.01～5.0 mg/kg范围内,4 种果蔬加标16 种杀菌剂的平均添加回收率在85.7%～103.9%范围内,批内相对标准偏差在2.6%～5.2%之间。16 种新型酰胺类杀菌剂的检出限为1.0×10－4～3.0×10－3 mg/kg,定量限为3.0×10－4～0.01 mg/kg。该方法能满足果蔬中16 种新型酰胺类杀菌剂残留量分析的要求。     

杀菌防霉剂在皮革中的应用

皮革中含有大量的蛋白质和油脂，在贮存和加工过程中极易受到微生物的污染而发生霉变，严重影响成革质量，因此应在制革过程中的不同阶段根据不同的需要添加杀菌防霉剂，本文主要介绍了制革过程中防霉剂的使用情况。     

Effect of fungi and fungicides on the preservation of wheat seed stored with high and low moisture content

The protective effect of the fungicides captan, chloratalonil, pentachloronitrobenzene, thiram and the commercial mixture of captan and carboxin against storage fungi, as well as the possible toxic effect on seed viability, were studied on seed of the Salamanca wheat variety. The research was conducted with wheat seed stored at 25°C with a high and low moisture content: (a) seed stored at a high relative humidity of 85%, to allow the development of fungi and (b) seed stored under dry conditions, with seed moisture contents below 13%. The germination of wheat seed, either with high or low moisture content, was slightly inhibited by the fungicide carboxin immediately following seed treatment. It appears that the fungicide temporarily promoted a slight effect of seed dormancy; however, this effect disappeared during the storage period. The fungicides chloratalonil, captan and carboxin+captan prevented the activity of the storage fungi, and protected the germination of the wheat seed stored at 85% relative humidity.     

THE DETERMINATION OF RESIDUES OF ETHYLENEBISDITHIOCARBAMATES AND THEIR HOMOLOGUES IN HOPS

Residues of ethylenebisdithiocarbamate and homologous fungicides are determined by hydrolysis with boiling sulphuric acid and colorimetric measurement of the liberated carbon disulphide. By its nature, the method is not specific for individual fungicides of this type but is simple and considered suitable for the screening of hop intake samples. Following the proposed introduction of a contractual residue limit of 60 mg/kg, this method was used by various laboratories to survey the 1980 and 1981 hop crops.     

An integrated strategy to control post-harvest decay of Embul banana by combining essential oils with modified atmosphere packaging

Mature Embul (Musa, AAB) bananas were treated with emulsions of either cinnamon bark or leaf (Cinnamomum zeylanicum) or clove (Syzygium aromaticum) oils to control post‐harvest diseases, packed under modified atmosphere (MA) using low‐density polyethylene (0.075 mm, LDPE) bags, and stored in a cold room (14 ± 1 °C, 90% RH) or at ambient temperature (28 ± 2 °C). The effects of the essential oils on post‐harvest diseases; physico‐chemical properties and organoleptic properties were determined and compared with controls and bananas treated with benomyl. Treatments with cinnamon bark and leaf oils controlled crown rot, whereas clove oil treatment did not affect crown rot development. Treatment with emulsions of cinnamon oils combined with MA packaging can be recommended as a safe, cost‐effective method for extending the storage life of Embul bananas up to 21 days in a cold room and 14 days at 28 ± 2 °C without affecting the organoleptic and physico‐chemical properties.     

In vitro effect of some fungicides on growth and aflatoxins production by Aspergillus flavus isolated from Capsicum powder

The aim of this study was to determine the effect of some pre-harvest fungicides on growth and aflatoxin (AF) production of three Aspergillus flavus strains found in Capsicum powder. Each isolate, previously isolated from paprika, chilli and smoked paprika, was inoculated on yeast extract sucrose agar and on a 3% paprika extract agar medium supplemented with different fungicides and incubated at 20 and 30°C during 7 days. Growth measurements were obtained on days 3, 5 and 7, and the AF production was determined on day 7. The significance of the effects of the factors (strain, medium, temperature, time and fungicides) and their interaction over colony diameter and AF production was determined. Temperature constrained the effectiveness of fungicides in reducing growth, the fungicides being most effective at 20°C. The efficacy of the fungicides over AF production depended on the medium used and temperature. The most effective fungicides in inhibiting growth and AF production, regardless of the strain tested or applied conditions, were tebuconazole 25% and mancozeb 80% applied at a concentration of 0.75 and 3.5?g?l^?1, respectively. Care should thus be taken in the choice of a suitable fungicide because their effectiveness may depend on intra-specific variation and temperature. Moreover, it is necessary to take into account that the most efficient fungicide in reducing growth is not always the best choice for pre-harvest treatments because it may promote AF production. Thus, the best fungicide is the one that can simultaneous prevent growth and AF production.     

不同杀菌剂对红香芋贮藏品质及抗氧化能力的影响

研究了不同杀菌剂(施保克和乔优)对红香芋贮藏品质指标及抗氧化能力的影响,探索可提高红香芋采后品质的杀菌剂,为红香芋贮藏技术的发展与应用提供理论指导。结果表明,2种杀菌剂处理均可降低红香芋贮藏期间的腐烂率,维持较高的Vc和蛋白质含量,减缓超氧化物变化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽还原酶(GR)和抗坏血酸过氧化物酶(APX)活性的下降,抑制POD活性的升高。与乔优相比,施保克更好地维持了红香芋的品质,并显著减缓了其抗氧化能力的下降。     

改良QuEChERS法结合气相色谱串联质谱测定果蔬中20种杀菌剂

目的 建立果蔬中20种杀菌剂(三环唑、五氯硝基苯、嘧霉胺、乙烯菌核利、百菌清、三唑酮、戊菌唑、腐霉利、三唑醇、多效唑、稻瘟灵、抑霉唑、咯菌腈、氟硅唑、腈菌唑、肟菌酯、丙环唑、咪鲜胺、腈苯唑、苯醚甲环唑)残留量的QuEChERS-GC/MS快速测定方法。方法 以生菜、毛瓜、葡萄、李子为原料, 样品经乙腈提取, PSA粉50.0 mg、Al2O3粉50.0 mg和NH2粉30.0 mg除杂净化后, 用GC/MS外标法定量。结果 三环唑等20种杀菌剂在0.025~0.250 mg/L的质量浓度范围内线性关系良好, 相关系数为0.9974~1.0000。添加水平为0.05、0.1、0.2 mg/kg时, 除百菌清外, 其余19种杀菌剂平均回收率范围均处于83%~112%之间, 相对标准偏差(RSD)小于11.0%, 方法的检出限(LOD)为0.2~11.8 μg/kg之间。结论 本方法具有灵敏、快速、简便等特点, 能满足果蔬中三环唑等20种农药杀菌剂的检测要求。     

Effect of sterol biosynthesis-inhibiting (SBI) fungicides on the fermentation rate and quality of young ale beer

The influence of five sterol biosynthesis-inhibiting (SBI) fungicides (cyproconazole, diniconazole, epoxiconazole, flutriafol, and tebuconazole) on the fermentation and quality of young ale beer was assessed. Fungicides were individually supplied to the brewer wort to obtain a concentration of 0.2 μg/ml. A noticeable influence of the fungicide residues on the fermentation rate was observed in all cases. From the third day onwards, the fermentation rate was low in all treated samples. At the end of fermentation (8 days), statistically significant differences (p < 0.05) were found for the extract and attenuation values, which were higher for all the samples treated with fungicides. As a consequence, a higher amount of residual sugars (mainly maltose and maltotriose) was found in the beer. No significant differences were found for the pH and the polyphenol content after fermentation among the blank and the treated samples, while the values of colour intensity (lower) and tint (higher) in the beer were statistically different.     

Antifungal properties and inhibitory effects upon aflatoxin production by Zingiber officinale essential oil in Aspergillus flavus

In this study, the efficacy of ginger (Zingiber officinale Roscoe) essential oil (GEO) in reducing A. flavus growth and aflatoxin production was investigated. Gas chromatography coupled to mass spectrometry and nuclear magnetic resonance spectroscopy showed that the major components of GEO were α‐zingiberene (23.85%) and geranial (14.16%). Mycelial growth of Aspergillus flavus was reduced significantly at a GEO concentration of 150 μg mL^?1, and complete inhibition of conidial germination was observed at a concentration of 10 μg mL^?1. Statistically significant inhibition of ergosterol biosynthesis was detected at a GEO concentration of 10 μg mL^?1. GEO was capable of fully inhibiting aflatoxin production by A. flavus at a concentration of 15 μg mL^?1. The results suggest that low concentrations of GEO are capable of inhibiting aflatoxin production; such ability could be valuable in the upcoming future for agricultural companies to better control aflatoxigenic fungi in agricultural products.