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1.
用QuEChERS方法对板栗样品中10种有机磷农药进行前处理优化,建立了板栗有机磷残留量的快速前处理方法,并进行验证。通过对比不同的提取溶剂、取样量、除水剂用量、净化剂用量确定板栗QuEChERS前处理的最佳组合,净化完成后用GC/MS检测。10种有机磷农药的线性相关系数均0.998,最低检出限为0.010~34 mg/kg,平均回收率为80.1%~105.4%,相对标准偏差值为3.5%~8.9%。该方法准确、快速、净化效果好,适用于板栗中多种有机磷农药残留的快速检测。  相似文献   

2.
以基质固相分散-气相色谱-串联质谱法(先将粉粹的竹笋样品经弗罗里硅土基质固相分散技术净化,然后用20 m L丙酮—正己烷溶液(1+2,v/v)淋洗,GC—MS/MS检测,外标法定量)检测竹笋中26种有机氯农药残留量。结果表明:26种有机氯农药在5~200μg/m L范围内线性良好,相关系数均大于0.99。在0.01~0.1 mg/kg浓度范围内,26种目标物的平均加标回收率为81.1%~108.9%,相对标准偏差在3.3%~9.5%。该方法具有较好的准确度和精密度,各项技术指标均能满足竹笋中26种有机氯农药的检测需要。  相似文献   

3.
采用固相萃取-液相色谱串联质谱仪,建立枸杞中9种有机磷农药的快速测定方法。样品经乙腈提取,过Carbon/NH2固相萃取柱净化,氮吹至干,残留物用乙腈-水（3：2,V/V）溶解后测定,采用正离子扫描方式进行仪器方法学研究,确定监测离子对,进行SRM模式定性定量分析。该方法的检出限（LOD）为0.12～9.8μg/L;在10～200μg/L范围内线性关系良好（r〉0.9961）。在20～100μg/L的添加水平上,9种有机磷农药的平均回收率在80.7%～122.4%之间,相对标准偏差（RSD）为2.75%～14.7%。该方法操作简单,灵敏度高,可用于枸杞中9种有机磷农残的测定。  相似文献   

4.
建立了分散固相萃取-高效液相色谱-串联质谱联用法测定食用林产品(香菇)中14种氨基甲酸酯类农药残留量的方法。样品经乙腈提取,PSA和少量GCB混合吸附剂分散固相萃取净化,然后采用HPLC-MS/MS测定,外标法定量。14种氨基甲酸酯类农药在0.005~0.100 0 mg/L范围内线性良好,相关系数均大于0.995 8。在0.01~0.05 mg/kg浓度范围内,14种目标物的平均加标回收率为70.0%~104.5%,相对标准偏差为3.2%~9.1%。该方法简单、快速、灵敏,可满足香菇中14种氨基甲酸酯类农药残留的检测需要。  相似文献   

5.
钱敏 《绿色科技》2013,(6):221-223
建立了毛细管气相色谱法测定蔬菜水果中28种有机磷农药残留量的分析方法,对实验水果蔬菜经乙腈提取,盐析,浓缩液丙酮溶解定容,采用ENVI-Carb固相萃取小柱净化,以10%丙酮-正己烷混合液洗脱,洗脱液采用DB-17毛细管柱和火焰光度检测器测定,一次进样可对蔬菜水果中28种有机磷农药进行检测,并且通过采用DB-1毛细管柱和氮磷检测器进行确证实验,准确度高。结果表明:样品加标平均回收率在72.8%～102.3%之间,相对标准偏差(RSD)在2.1%～6.6%之间,检出限(LOD)在0.017～0.200mg/kg之间。实验表明,该检测方法简便、快速、灵敏、准确,各项技术指标均能满足农药残留检测的要求,适合蔬菜水果中有机磷农药多残留的日常检验。  相似文献   

6.
南竹过热水萃取物成分的GC／MS分析   总被引：1，自引：1，他引：0  
以新鲜南竹为原料,采用工业可利用的竹片浸提工艺进行过热水萃取,然后利用气相色谱/质谱(GC/MS)联用技术对萃取物成分进行分析,结果表明:在新鲜南竹片过热水萃取物GC/MS分析中,共分离出36个峰,鉴定出25个化合物,占总峰面积的97.35%.主要成分为二十七烷(cas)(26.2%)、14-á-H-pregna(15.71%),2,6,10-甲基-十四烷(15.55%)、甲基-9,10-二氟次甲基-9-十八碳二烯酸(12.84%)、1,2-邻苯二甲酸二丁基酯(8.93%)、1,2-邻苯二甲酸,双2-甲丙酯(2.65%)、1-五十七醇(1.88%)、isochiapinb(1.88%)、10-甲氧基-nb-à-甲基二十九醇(1.63%)等.南竹过热水萃取物中绝大部分成分具有医药作用,并含有香料.  相似文献   

7.
为建立液相色谱-串联质谱法(LC-MS/MS)检测饲料中19种氟喹诺酮类和14种β-受体激动剂类药物的残留量,采用了样品经0.2mol/L盐酸溶液提取,阳离子柱交换固相萃取净化后,以乙腈-0.1%甲酸水溶液为流动相,LC-MS/MS法检测,同时定性定量测定33种兽药残留。结果表明：33种兽药在色谱柱上分离效果较好,回收率在61.1%～112.7%之间,相对标准偏差小于14.7%。该方法快速、简单,能满足33种兽药残留分析的要求,适用于测定饲料中19种氟喹诺酮类和14种β-受体激动剂类药物的残留量。  相似文献   

8.
建立了一种可快速净化果蔬中有机磷农药残留测定的方法。在NY/T 761-2008标准的基础上,采用多功能的免疫亲和柱(MycoSep 226 AflaZon+)对杨梅Myrica rubra,黄瓜Cucumis sativus,辣椒Capsicum annuum样品的有机磷农药提取液进行净化,净化过程可在1 min内钟完成,净化液可直接用于测定,并可明显降低对检测设备的污染程度。试验结果表明,所测定的敌敌畏、丙溴磷、乙酰甲胺磷等19种常见有机磷农药在0.02～1.00 mg·L~(-1)范围内有良好的线性关系,相关系数(r~2)均大于0.999;重现性良好,多次重复测定相对标准偏差仅0.84%,明显优于标准规定处理方法;低、中、高浓度的加标回收率分别在85.4%～96.1%,89.7%～97.1%,90.2%～103%之间,总体回收率均在85%以上。  相似文献   

9.
为探索木制品中阻燃剂检测方法,本文利用微波辅助萃取探索并比较了两种木材及其制品中3种有机磷阻燃剂检测方法。气相色谱-质谱方法(GC-MS)检测TCEP、TCPP、TDCP三种阻燃剂回收率87.0%~111.2%,相对标准偏差3.6%~16.3%,检出限分别29,20,14μg·kg~(-1);液相色谱-串级质谱方法(LC-MS/MS)检测TCEP、TCPP、TDCP三种阻燃剂回收率82.7%~98.3%,相对标准偏差1.8%~10.8%,检出限分别8,2,15μg·kg~(-1)。两种方法提取效果较好,准确度和精密度满足试验要求,均能够有效地检测木材及其制品中3种有机磷阻燃剂。  相似文献   

10.
建立了分散固相萃取-气相色谱三重四极杆串联质谱法测定玫瑰花茶中的13种菊酯类农药的分析方法。玫瑰花茶经乙腈和甲酸(99∶1v/v)提取后,QuEChERs净化,MRM模式测定,外标法定量。以QuEChERs作为前处理方法,优化吸附剂组合和用量,以及碰撞能和驻留时间。结果表明:13种菊酯含量在10～200μg/L间呈良好的线性关系,相关系数r^2均大于0.995。以空白基质进行3个水平添加浓度0.02～0.20 mg/kg,平均回收率为75.4%～87.6%,相对标准偏差(RSD)为1.9%～7.7%,该方法的简单快速,灵敏度、准确度和精密度均符合菊酯类农药测定的技术要求。  相似文献   

11.

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.  相似文献   

12.

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.  相似文献   

13.

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.  相似文献   

14.

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.  相似文献   

15.
本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。  相似文献   

16.

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.  相似文献   

17.
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18.

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.  相似文献   

19.
In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.  相似文献   

20.
The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha−1 target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha−1. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1); (2) Lolium perenne L. var. Tove (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m2, with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

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