Simultaneous determination and method validation of difenoconazole,propiconazole and pyraclostrobin in pepper and soil by LC–MS/MS in field trial samples from three provinces,China

A liquid chromatography–electrospray ionization tandem mass spectrometry method was developed for simple and accurate detection of the fungicides difenoconazole, propiconazole and pyraclostrobin in peppers and soil. Three fungicides residues were extracted from samples by acetonitrile and cleaned up by dispersive solid‐phase extraction before instrumental analysis. The accuracy and precision of the method were evaluated by conducting an intra‐ and inter‐day recovery experiment. The limits of quantification and detection of difenoconazole, propiconazole and pyraclostrobin in pepper and soil were 0.005 and 0.0015 mg/kg, respectively. The recoveries were investigated by spiking pepper and soil at three levels, and were found to be in the ranges 79.62–103.15% for difenoconazole, 85.94–103.35% for propiconazole and 80.14–97.69% for pyraclostrobin, with relative standard deviations <6.5%. Field experiments were conducted in three locations in China. The half‐lives of difenoconazole, propiconazole and pyraclostrobin were 5.3–11.5 days in peppers and 6.1–32.5 days in soil. At harvest, pepper samples were found to contain difenoconazole, propiconazole and pyraclostrobin well below the maximum residue limits of European Union at the interval of 21 days after last application following the recommended dosage.     

高效液相色谱-串联质谱法测定辣椒及辣椒制品中金刚烷胺残留

建立了高效液相色谱-串联质谱(HPLC-MS/MS)测定辣椒及辣椒制品中金刚烷胺残留的分析方法。样品采用1%三氯乙酸溶液-甲醇(1∶1)提取,经Oasis-MCX固相萃取小柱净化后用Atlantis T3 C18柱进行分离,以0.1%甲酸水-乙腈(85∶15)作为流动相进行等度洗脱,电喷雾正离子(ESI+)扫描方式下多反应监测(MRM)模式对样品进行检测。实验结果表明,金刚烷胺在1.0~50μg/kg范围内线性关系良好,鲜辣椒样品的定量下限为1.0μg/kg,干辣椒及干辣椒制品为5.0μg/kg。鲜辣椒在1.0,2.0,5.0μg/kg加标水平下的回收率为72.2%~98.2%,相对标准偏差(n=6)为1.2%~4.6%;干辣椒及干辣椒制品在5.0,10.0,25.0μg/kg加标水平的回收率为64.2%~81.6%,相对标准偏差(n=6)为1.3%~6.3%。该方法操作简单、灵敏度高、重现性好,可用于辣椒及辣椒制品中金刚烷胺残留量的检测。     

Efficacy of selected triorganotin(IV) compounds on leaves against Phytophthora palmivora (Butler) Butler isolated from black pepper and cocoa

Several triorganotin(IV) compounds and Terrazole® 35 WP were screened for their in vitro antifungal activity against three isolates of Phytophthora palmivora. Two isolates (isolates Phy. 2 and Phy. 334) were obtained from black pepper (Piper nigrum L.) and one isolate (isolate Phy. 56) from cocoa leaves (Cacao theobromae). ED₅₀ values for radial growth of the isolates ranged from 0.09 to 1,700 μg cm^?3 for the triorganotin(IV) compounds and from 3.46 to 1 227 000 μg cm^?3 for Terrazole®. Diphenylbutyltin bromide exhibited the highest antifungal activity against the three isolates of P. palmivora with ED₅₀ values ranging from 0.30 to 0.73 μg cm^?3. Diphenylbutyltin bromide was equally effective against a freshly isolated virulent culture of P. palmivora (isolate Phy. 346) from black pepper leaves in Sarawak, East Malaysia, yielding an ED₅₀ value for radial growth of 0.87 μg cm^?3 and a probit-log concentration regression line slope value of 1.04. In vitro efficacy of diphenylbutyltin bromide against isolate Phy. 346 using detached healthy pepper leaves showed 40–75% infection of leaves at 100 μg cm^?3 and no infection at 500 μg cm^?3. Diphenylbutyltin bromide at 100 μg cm^?3, however, inhibited the diameter of lesion by 43.3–73.7% compared with the untreated controls. Black pepper leaves treated with Terrazole® at 778 μg cm^?3 exhibited 5.3–33.3% inhibition of lesion diameter compared with the untreated controls, where 90–100% of the leaves were infected. Concentrations of diphenylbutyltin bromide of 1000–2500 μg cm^?3 caused some injury lesions on the leaves. From the results obtained, it appears that diphenylbutyltin bromide could be used as a protective spray or drench against P. palmivora infection of black pepper at 100–500 μg cm^?3.     

Determination of alachlor residues in pepper and pepper leaf using gas chromatography and confirmed via mass spectrometry with matrix protection

Alachlor residues were determined in pepper and pepper leaf, after 49 days of manufacturer‐recommended single‐ and double‐dose application to the soil and plant. The samples were extracted with acetonitrile, partitioned with n‐hexane, and purified through solid‐phase extraction, and finally detected with a gas chromatography–microelectron capture detector. The linearity of the analytical response across the studied range of concentrations (0.05–4.0 µg/mL) was excellent, obtaining coefficients of determination (r²) of 0.999. Recovery studies were carried out on spiked pepper and pepper leaf samples, at two concentrations levels (0.2 and 1.0 mg/kg), with three replicates performed at each level. Mean recoveries of 73.1–109.0% with relative standard deviations of 1.3–2.3% were obtained. The method was successfully applied to field samples, and alachlor residue was found in pepper (0.02 mg/kg) and pepper leaf (0.03 mg/kg), at levels lower than the maximum residue limits (0.2 mg/kg) set by the Korea Food and Drug Administration. The field‐detected residues were further confirmed with gas chromatography–mass spectrometry with the help of pepper leaf matrix protection. Copyright © 2013 John Wiley & Sons, Ltd.     

一种去除椒盐噪声的自适应模糊中值滤波算法

针对传统中值滤波算法降噪性能不佳以及易造成图像细节模糊的问题,提出了一种自适应模糊中值滤波算法。 滤波过程分为噪声检测和噪声去除2个阶段。噪声检测阶段：采用极值法检测噪声,将图像的像素点分为两类,即疑似噪声点和信号点。 通过疑似像素点和与其相邻的已处理的像素点的平均绝对灰度差值定义模糊隶属度函数,利用该函数对疑似噪声点是否为噪声进行模糊分类。 噪声去除阶段：信号点保持原值输出,对于疑似噪声点的3种分类结果,采用模糊加权的中值滤波器进行统一处理。 实验结果表明,较于多种传统滤波方法,该算法能更有效地去除椒盐噪声,保护图像细节。     

Study of water transpiration features of sweet pepper using a thermal imaging system and non-destructive quality monitoring during post-harvest storage

Summary Sweet pepper is susceptible to relatively fast quality changes and its quality is influenced strongly by water or mass losses mainly due to transpiration processes during post-harvest. The aim of this study was the investigation of different storage conditions' effect on quality maintenance of pepper using surface thermal imaging, measurement of overall static stiffness and low-mass impact stiffness as non-destructive methods. Post-harvest keeping quality of pepper samples increased and unfavourable quality degradation was prevented under low, non-chilling temperatures together with the use of LDPE-packaging film resulted in high quality and fresh appearance after more than two weeks long storage period.     

Physicochemical Properties and Composition of Lipids from Capsicum annuum Seeds

The mass of 1000Capsicum annuum(Solanaceae) seeds and their moisture, oil and ash contents were determined. The lipid composition and acid components were studied. Low-molecular-weight fatty acids, concentrated in the ester fraction, were detected     

库仑滴定法测定Vitamin C片及黄瓜、青椒中抗坏血酸的含量

建立了以1.0 mol.L-1碘化钾和1.0 mol.L-1醋酸混合液作为电解液的恒电流库仑滴定法测定抗坏血酸含量的方法。结果表明,方法的回收率在98.3%~100.8%之间,RSD在0.21%~0.56%(n=3)。该法可直接用于V itam in C片及黄瓜、青椒等样品中抗坏血酸含量的测定,方法简便灵敏,结果令人满意。     

Quality variation and standardization of black pepper (Piper nigrum): A comparative geographical evaluation based on instrumental and metabolomics analysis

Black pepper (Piper nigrum; BP), known as the ‘king of spices’, imported from various countries is widely available in Saudi Arabian markets, as its demand as a food as well as a medicine for minor ailments is increasing in the country. However, there is a lack of appropriate information regarding these samples in terms of quality variation and standardization. We thus aimed to evaluate the quality and standardize the BP sample with respect to its physicochemical characters, active principle variation [i.e. piperine (PPN)], toxicity, and biological activity. The main focus is to validate whether any difference exists in the quality and quantity of active principle in these samples. For this purpose, physicochemical (chemical tests and ash values) and instrumental analyses [accelerated solvent extraction (ASE), ultra-high-pressure liquid chromatography (UHPLC)-diode array detector, infrared (IR), nuclear magnetic resonance (NMR), and inductively coupled plasma-MS (ICP-MS)] and biological evaluation {in vitro antioxidant activity [2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] and cytotoxicity assay} were performed. An extract yield (g) with %recovery of 2.26 ± 4.24 (11.3) was obtained for the Vietnamese sample, using a fast and rapid method of extraction (ASE). These values were 1.22 ± 2.64 (6.1) and 0.75 ± 1.69 (3.75) for the Pakistani and Indian samples. Physicochemical tests revealed the presence of flavonoids and phenolic compounds in all samples; however, in the Vietnamese sample a low amount of total, acid-insoluble, and high water-soluble ash value was noted. IR and NMR was applied to further standardize the samples. Results of ICP-MS analysis showed a high amount of macronutrients and micronutrients in the samples tested while UHPLC analysis revealed a high amount of PPN (ng/mL) in the Pakistani sample (1,362,614.09); these values were 1,051,848.04 and 768,512.81 for the Vietnamese and Indian samples, respectively. In vitro antioxidant and cytotoxicity activities revealed higher potential for the Vietnamese sample. The samples were properly standardized and effectively differentiated in terms of quality and biological activities using a fast and reliable method, however it certainly does not mean that a particular geographical region is more better or productive in terms of herbal products.     

Potential beneficial and/or adverse effects of Capsicum annuum L. (cv. Fiesta) at two stage of ripening in CD-1 mice

Abstract

Aim of the present study was to evaluate the potential beneficial and/or adverse effects of Capsicum annuum L. (cv. Fiesta) extracts at two stage of ripening (immature and mature), and at two dosages (low and high) by evaluation of biochemical profile and oxidative status in CD-1 mice. The extracts were daily administered to mice by oral gavage for 20?days. At the end of the trial, the animals were euthanatized and blood was collected. Evidence of liver damage (increase of AST, ALT and bilirubin) in the group receiving the higher dosage of immature peppers extract were observed. Even if no adverse effects were seen at the lower doses, also no signs of beneficial effects in term of health status, biochemical profile and oxidative status were detected. These results are in contrast with in vitro findings and raise doubts about the possible use of Capsicum annuum L. (cv. Fiesta) as a nutritional supplement.