佛山市蔬菜中若干重金属元素含量调查与分析

对广东佛山市蔬菜中重金属含量进行了调查与分析。结果表明,蔬菜中重金属元素含量取决于蔬菜种类和土壤环境,佛山市蔬菜中重金属元素含量基本上是正常的,仅个别样点土壤受污染,蔬菜重金属元素含量异常。蔬菜中重金属元素含量由高到低顺序大体上是:叶菜类,瓜果类蔬菜,根菜类蔬菜。蔬菜必需元素锌、铜含量比汞、镉、铅、铬、镍等非必需元素含量高。     

超高效液相色谱-大气压化学电离-三重四极杆质谱法同时测定血浆、尿液和瓜果类蔬菜中葫芦素B、E和I

建立了超高效液相色谱-三重四极杆质谱测定血浆、尿液和瓜果类蔬菜中葫芦素B、E和I的检测方法。血浆和尿液样品经固相支持液液萃取法（SLE）提取净化,瓜果类蔬菜样品经乙腈提取后用水稀释。以XBridge BEH C₁₈色谱柱（100 mm×3.0 mm,2.5 μm）为分析柱进行分离,以甲醇-0.025%（v/v）氨水溶液为流动相进行梯度洗脱。采用大气压化学电离源,在负离子、多反应监测（MRM）模式下检测,以夹竹桃甙作为内标物,基质工作曲线内标法定量血浆和尿液中3种葫芦素;以溶剂标准曲线外标法定量瓜果类蔬菜中的待测物。血浆和尿液中3种葫芦素的检出限均为0.03 μg/L,平均加标回收率为89.0%~113%,相对标准偏差为1.7%~12.2%（n=6）;瓜果类蔬菜中3种葫芦素的检出限为5~10 μg/kg,平均加标回收率为87.6%~114%,相对标准偏差为4.1%~11.1%（n=6）。该法简单、灵敏、准确,已应用于食用苦葫芦瓜引起中毒的病人血浆和尿液,以及葫芦瓜的检测,并检出了葫芦素B。     

蔬菜瓜果中氯吡脲残留检测方法研究

研究并建立了测定蔬菜、瓜果中氯吡脲残留量的气相色谱-电子捕获检测法(GC-ECD)、液相色谱-紫外检测法(HPLC-UV)。样品经乙腈提取,过滤后进行盐析,上层有机相用QuEChERS方法净化,净化后的上清液定容后供色谱检测。通过分析比较两种不同方法的检测结果,蔬菜、瓜果中氯吡脲的残留量既可用气相色谱法也可用液相色谱法检测,但从样品的干扰情况、检测灵敏度和方法稳定性等综合因素来看,液相色谱法更适合蔬菜、瓜果中氯吡脲残留量的检测。     

成都市土壤-植物系统铅污染状况初步研究

为研究成都市土壤-植物系统铅污染状况，分析了成都市五种蔬菜及其根系土的铅含量。结果表明，土壤铅含量变化范围61．0～115．0mg/kg，均值为77．3mg/kg，所有样品含量均超过成都市土壤环境背景值，以城东和城南污染最为严重；蔬菜中铅含量以莴笋叶最高，萝卜最低，叶菜类高于瓜果类；蔬菜污染严重区与土壤污染区差别明显，说明土壤铅和植物铅污染源不同。     

固体水果清洗块通过鉴定

不久前,由大连轻工业学院研制开发的“瓜果蔬菜残留农药、化肥清洗块”项目通过了由大连市科技局组织的技术鉴定。 专家组一致认为,固体清除农药残留的技术是一个民生项目,突破了原有的液态清洗剂由上而下的清洗过程。经过固体清洗剂清洗的水果,经检测符合国际残留农药的标准。固体清洗剂成功还原了蔬菜水果的原始绿色,项目成果在清除果蔬表面残留农药技术方面达到了国际先进水平。     

2017食品/环境/职业卫生标准物质应用技术研讨会成功在京举办

<正>2017年2月25日,坛墨质检-标准物质中心在北京亦庄经济开发区丰大国际酒店成功举办了2017食品/环境/职业卫生标准物质应用技术研讨会。随着全球科技的迅速发展,国家、市场和消费者对各个行业的产品品质要求都在不断提高。小到蔬菜瓜果,大到航天军工,标准物质在社会生活中扮演着越来越重要的角色。从建国开始的行业空白,到现在每年     

我国66种蔬菜矿质营养成分的综合评价

通过对我国66种常用新鲜蔬菜的K、Na、Ca、Mg、Fe、Mn、Zn、Cu、P、Se等10种矿质营养元素含量数据的深度挖掘,用聚类分析法建立了蔬菜的矿质营养成分谱。结果表明,66种蔬菜按其所含矿质元素含量的高低及其组合状况可有序地划分为6个组：即富K、P、Zn型蔬菜,富Ca蔬菜,富Mn、Fe、Se型蔬菜,富zn、Fe、P型蔬菜、各种营养成分的配合较为均衡的蔬菜和低K、P型蔬菜。按照蔬菜的w（Zn）／w（Cu）、w（Ca）／w（Mg）、w（Na）／w（K）比值序列,为人们尤其是高血压和冠心病患者科学合理地选择和搭配蔬菜提供了参考。     

蔬菜中有机磷和氨基甲酸酯类农药残留的气相色谱测定方法探讨

用气相色谱法同时测定蔬菜中的甲胺磷、乙酰甲胺磷、氧化乐果、甲拌磷、甲基对硫磷、对硫磷、毒死蜱等有机磷农残及克百威、抗蚜威等氨基甲酸酯类农残.采用丙酮-二氯甲烷(3:7 v/v)混合溶剂提取蔬菜中有机磷及氨基甲酸酯类农药残留,经中性氧化铝和活性碳净化,DB-IMS石英弹性毛细管柱分离,在氮磷检测器(NPD)上测定.同时讨论了样品前处理方法及其测定的最佳色谱参数的选择.方法对蔬菜空白样品的平均添加回收率为77%～116%,RSD为0.3%～15%.该方法简便、快速,准确,可操作性强.为其它样品的有机磷及氨基甲酸酯类农残的分析测定提供参考依据.     

蔬菜中有机磷和氨基甲酸酯类农药多残留联合检测方法

有机磷和氨基甲酸酯类农药是蔬菜生产中常用的杀虫剂,我国70%的有机磷杀虫剂是剧毒、高毒农药。农药如果使用不当,不但药效不好,还会发生药害,污染环境,造成人畜中毒。因此,加强对农药残留的监控,禁止农药残留超标的蔬菜进入市场,确保消费安全已成为当务之急。本文报道用毛细管气相色谱法测定蔬菜中有机磷和氨基甲酸酯类农药多残留的联合检测方法。     

蔬菜中氨基甲酸酯类农药残留的固相微萃取分离和HPLC法检测

采用固相微萃取制样,荧光检测器高效液相色谱法测定了蔬菜中氨基甲酸酯农药残留. 确定了影响固相微萃取效果的萃取头涂层、萃取条件、洗脱条件和蔬菜样品分析处理方法. 结果表明,蔬菜中氨基甲酸酯类农药的检出限在0.4×10-9～40×10-9 g/g范围内,线性范围为0.05～1 mg/L,回收率74.4%～108.4%,相对标准偏差(RSD)4.26%～13.97%.     

Multi-residue pesticide analysis in fruits and vegetables by liquid chromatography-time-of-flight mass spectrometry

In this work, a new multi-residue methodology using liquid chromatography-time-of-flight mass spectrometry (LC-TOF-MS) for the quantitative (routine) analysis of 15 pesticide residues has been developed. The analytical performance of the method was evaluated for different types of fruit and vegetables: pepper, broccoli, tomato, orange, lemon, apple and melon. The accurate mass measurements were compared in different matrices at significantly different concentration levels (from 0.01 to 0.5 mg/kg) obtaining accuracy errors lower than 2 ppm, which is well within the accepted limits for elemental confirmation. Linearity of response over two orders of magnitude was demonstrated (r > 0.99). Matrix effects resulting in suppression or enhancement of the response were frequently observed, most notably in broccoli and citrus. Instrumental limits of detection (LOD) were between 0.0005 and 0.03 mg/kg depending on the commodity and pesticide studied, all being within European Union regulations for food monitoring program. Finally, the methodology was applied to the analysis of two samples from an inter-laboratory exercise. The high degree of confirmation for target pesticides by accurate mass measurements demonstrated the applicability of the method in routine analysis. This study is a valuable indicator of the potential of LC-TOF-MS for quantitative multi-residue analysis of pesticides in vegetables and fruits.     

Kinetic spectrophotometric determination of ascorbic acid by reduction of toluidine blue

A simple kinetic method is described for the determination of ascorbic acid. The procedure is based on the reduction of toluidine blue with ascorbic acid. The rate of reaction is followed by measuring the decrease in absorbance of toluidine blue (lambda(max) = 600 nm) as a result of its decolorization upon reduction by ascorbic acid. Ascorbic acid in the range of 3-35 microg/ml was determined using slope and fixed time methods of analysis, while the variable time method allowed the determination of 5-50 microg/ml of ascorbic acid. The percent relative standard deviation of the method varied from 0.78 to 1.32% depending on the kinetic method used. The high sensitivity of the method also allows determination of low levels of ascorbic acid in some fruits and vegetables such as dew melon, water melon, parsley and coriander.     

Antimicrobial activity and agricultural properties of bitter melon (Momordica charantia L.) grown in northern parts of Turkey: a case study for adaptation

This study was designed to determine the adaptation capability of bitter melon (Momordica charantia L.), which is widely grown in tropical and subtropical climates, in northern parts of Turkey. In this study, plant height, number of fruits, fruit length, fruit width, number of seeds and fruit weight of bitter melon grown in field conditions were determined. The antimicrobial effect of the ethanol extract of fruit and seeds against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Salmonella typhi, Aspergillus niger and Candida albicans microorganisms was tested in vitro by the disc diffusion method. In conclusion, plant height (260 cm), number of fruits (16 per plant), number of seeds (30.2 per fruit), fruit width (3.8 cm), fruit length (10.6 cm) and fruit weight (117.28 g fruit^? 1) were determined; fruits were found to have antimicrobial activity against A. niger; oil and seeds were found to have antimicrobial activity against A. niger and E. coli.     

Phytosanitary irradiation for export of fresh produce: commercial adoption in Hawaii and current issues

Hawaii is a pioneer in the use of phytosanitary irradiation. Irradiation is an approved treatment to control quarantine insect pests in 17 fruits and 7 vegetables for export from Hawaii to the US mainland. The commercial X-ray irradiation facility, Hawaii Pride LLC, has been shipping tropical fruits and vegetables to the US mainland using irradiation since 2000. Hawaiian purple sweet potato is the highest volume product with annual exports of more than 12 million lbs (5,500 tonnes). The advent of generic radiation treatments for tephritid fruit flies (150 Gy) and other insects (400 Gy) has accelerated commodity export approvals and facilitated adoption by foreign trading partners. Current impediments to wider adoption include the labeling requirement, the 1 kGy limit for fresh horticultural products, and non-acceptance of phytosanitary irradiation in Japan and the European Union. USDA Animal and Plant Health Inspection Service (APHIS) has restricted the use of modified atmosphere packaging (MAP) for irradiated fresh fruits exported to the US due to possible increased radio-tolerance in the target insects. Data are presented for response of melon fly in papaya to several types of MAP with radiation treatment at 45–65 Gy. Low oxygen atmospheres can increase insect radio-tolerance, but the effect is dependent on oxygen concentration and radiation dose.     

高效液相色谱法同时测定蔬菜水果中的12种农药残留

建立了同时测定蔬菜水果中12种农药残留的反相高效液相色谱分析方法。将样品捣碎,用乙酸乙酯超声提取,经Florisil固相萃取柱净化、正己烷-二氯甲烷(体积比为1∶1)洗脱、氮气吹干、甲醇溶解并定容后,采用高效液相色谱柱分离、紫外检测,以外标法定量。结果表明：12种农药标准曲线的线性相关系数范围为0.9985~0.9999;检测限为0.14~2.65 ng;在水果中的平均加标回收率为62.2%~118.2%,相对标准偏差(RSD)为0.56%~11.8%;在蔬菜中的平均加标回收率为52.1%~124.6%,RSD为0.89%~18.4%。用所建立的方法成功地测定了白菜、莲白、黄瓜、苹果、梨等40份样品中的农药残留。方法具有快速、简便、准确、灵敏、重现性较好的特点,适合于蔬菜水果样品中多种微量农药残留的测定。     

Spectrophotometric Estimation of Carbaryl Residue in Some Home Garden Vegetables

Abstract

Residues of carbaryl (1-Naphthyl N-methly carbamate) were determined in the fruit and foliage of seven home garden vegetables by a spectrophotometric method. Residues at harvest averaged the following levels; cabbage (head, 0.0 ppm), cucumber (foliage 0.0 ppm; fruit, 0.05 ppm), garden bush beans (fruit, 0.0 ppm), Okra (foliage, 0.0 ppm; fruit, 0.01 ppm), pepper (foliage, 2.72 ppm; fruit, 0.9 ppm), squash (foliage, 6.55 ppm; fruit, 0.0 ppm), and tomato (foliage, 2.07 ppm; green fruit, 0.09 ppm; mature fruit, 0.03 opm). Foliage of the vegetables contained higher concentrations of the insecticide, in most cases, than did the fruits. Even with excessive applications, the carbaryl residues were found to be below the tolerance level established by EPA.     

Properties and determination of pesticides in fruits and vegetables

The intensive development of agriculture means that more and more toxic organic and inorganic compounds are entering the environment. Because of their widespread use, stability, selective toxicity and bioaccumulation, pesticides are among the most toxic substances contaminating the environment. They are particularly dangerous in fruit and vegetables, by which people are exposed to them. It is therefore crucial to monitor pesticide residues in fruit and vegetables using all available analytical methods.We set out the problems in the determination of organonitrogen and organophosphorus pesticides in samples of fruit and vegetables, including the complexity and the diversity of matrices in biological materials, and the very low level of pesticides present, as a result of which target analytes have to be isolated and then enriched prior to final determination.We discuss the various stages in the determination of pesticide residues in fruit and vegetables. We present results from the literature in the context of Maximum Residue Levels (MRLs) of target pesticides in fruit and vegetable samples. We discuss the merits of the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) technique and two-dimensional gas chromatography.     

蔬菜水果中无机砷测定方法改进研究

研究改进了应用原子荧光法测定蔬菜水果中无机砷的前处理方法,用6 mol/L盐酸在70℃水浴中提取1 h,使试样充分浸提。吸取4 mL浸提液于10 mL容量瓶或具塞刻度试管中,加碘化钾-硫脲混合液1 mL,消泡剂(正辛醇)3~5滴,加水定容后测定试样中的无机砷。方法检出限为干样0.02 mg/kg,鲜样0.01 mg/kg,完全能够满足国家卫生标准限量和农产品认证指标测定的要求。