Interpreting the relationship between pheromone component emission from commercial lures and captures of Helicoverpa zea (boddie) in bucket and cone traps

Abstract

Male corn earworm moths, Helicoverpa zea (Boddie), were captured in conical Texas pheromone traps (cone traps) and bucket traps baited with four different commercial lures manufactured by three different manufacturers. Because significant numbers were captured in bucket traps baited with some of the lures, and none with others, the volatile emissions from all of the lures were sampled and analyzed by gas Chromatographic methods. The numbers of males captured in two types of trap were compared with bait emissions in an endeavor to define a more effective lure for bucket traps. The lure from one manufacturer captured the same numbers of males in both trap types; one captured more in bucket traps than in cone traps, and another captured only a small number in bucket traps. The emission rate of all active compounds from each of the different lures was approximately linear for the duration of the assays. A gas‐liquid Chromatographic peak associated with a third compound, (Z)‐9‐tetradecenal, which reduces behavioral responses, was observed in the emissions from all lures evaluated. The effectiveness of the Hercon (Emmigsville, PA) lure in capturing males in both types of trap was associated with a lower emission of (Z)‐l 1‐hexadecenal, (Z)‐9‐hexadecenal and (Z)‐9‐tetradecenal than from the other lures.     

盐析分相微萃取—高效液相色谱法测定水中含氯除草剂

采用盐析分相微萃取—高效液相色谱法同时测定水中3种含氯除草剂，建立并优化了反相离子对液相色谱条件，考察了萃取剂种类、盐析剂的种类和加入量及试样pH对萃取效果的影响。对氯苯氧乙酸、2，4-二氯苯氧乙酸和2，4-滴丁酯的质量浓度在0.1~100.0mg/L内与色谱峰面积呈良好的线性关系，相关系数不低于0.9992。平均回收率分别为96.29%、79.16%和70.21%，相对标准偏差小于5.3%。该方法操作简便、绿色环保，适合于水中含氯除草剂的测定。     

离子色谱法测定大气中的甲磺酸

建立了以玻璃纤维膜-KB120气溶胶采样器采集大气中甲磺酸的采样方法;以0.1mmol·l-1H3BO3/0.1mmol·l-1 Na2B4O7为淋洗液的甲磺酸离子色谱分析方法.分析方法的精密度和准确度分别为5%和4%.并实测了青岛冬季大气气溶胶中MSA,SO2-4和NO-3的平均浓度分别为0.10μg·m-3,30.40μg·m -3和17.98μg·m-3.     

星形大分子液晶在气相色谱分析中的应用研究

将首次合成的偶氮苯硅氧烷类星形液晶大分子化合物用于毛细管柱气相色谱固定液 ,在其相转变温度附近具有良好的选择性 ,成功地分离了二甲酚异构体。     

GC-PID联用直接测定大气中痕量烃类化合物

作者把气相色谱仪(GC)与自行研制的光离子化检测器(PID)联用,实现了大气中痕量烃类化合物的直接测定,给出了仪器的构成和性能指标及测量结果.     

Monitoring the formation of trihalomethanes in the effluents from a shrimp hatchery

Formation of trihalomethanes (THM) was monitored at the Laboratório de Camarões Marinhos (LCM) from the Universidade Federal de Santa Catarina. THM could be present because chlorinated effluents from disinfection are discharged from the different hatchery rooms. THM quantification was done through an analytical methodology using Purge&;Trap coupled with a gas chromatograph equipped with an electron capture detector. Relative standard deviation (RSD), limit of detection (LOD) and limit of quantification (LOQ) for the methodology corresponded to the ranges of 8–17%; 0.01–0.03 μg L^?1 and 0.03–0.08 μg L^?1, respectively. Linear working range was of 0.1–8.0 μg L^?1 for all compounds. Enrichment and recovery method was applied to evaluate possible matrix effects and the results varied from 71.2% to 107.9%. LCM was monitored between August and December, 2004. This study showed that THM did not increase with the increase in postlarvae production and also that the aquatic life and the surrounding environment were not affected.     

Assessment of organochlorine pesticide residues in Atlantic Rain Forest fragments, Rio de Janeiro, Brazil

A superficial water quality survey in a watershed of the Paraíba do Sul River, the main water supply for the most populated cities of southeastern Brazil, was held in order to assess the impact of the expansion of agricultural activity in the near border of the Atlantic Rain Forest. The aim of this study was to investigate the presence of priority organochlorine pollutants in soils and superficial waters of Atlantic rainforest fragments in Teresópolis, Rio de Janeiro State. Soil sample preparations were compared by using ultrasound, microwave assisted extraction and Soxhlet extraction. Recoveries of matrix spiked samples ranged from 70 to 130%. Analysis of a certified soil material showed recoveries ranging from 71 to 234%. Although low concentrations of organochlorine residues were found in water and soil samples, this area is of environmental importance and concern, thus demanding a monitoring program of its compartments.     

Octanol–air partition coefficients of polybrominated biphenyls

The octanol–air partition coefficients (K_OA) for PBB15, PBB26, PBB31, PBB49, PBB103 and PBB153 were determined as a function of temperature using a gas chromatographic retention time technique with 1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane (p,p′-DDT) as a reference substance. The internal energies of phase change from octanol to air (Δ_OAU) were calculated for the six compounds and were in the range from 74 to 116 kJ mol⁻¹. Simple regression equations of log K_OA versus relative retention times (RRTs) on gas chromatography (GC), and log K_OA versus molecular connectivity indexes (MCI) were obtained, for which the correlation coefficients (r²) were greater than 0.985 at 283.15 K and 298.15 K. Thus the K_OA values of the remaining PBBs can be predicted by using their RRTs and MCI according to these relationships.     

官厅水库沉积物表层中的有机氯农药分布特征及风险评价

采用气相色谱法对北京市官厅水库沉积物表层中持久性有机氯农药(OCPs)的残留状况进行了调查,并对有机氯农药污染水平和生态风险作出评价。结果表明:沉积物中有机氯农药总含量为8.48 ng/g～24.40 ng/g,其中HCHs和DDTs的含量较高,分别为1.11 ng/g～7.73 ng/g和2.97 ng/g～10.52 ng/g,其组分特征为来自环境的残留。与沉积物风险评估低值(ERL)和风险评估中值(ERM)对比评价沉积物中有机污染物的风险程度,官厅水库沉积物表层中的有机氯农药存在一定的生态风险。     

单柱阳离子色谱快速分析白云石中高含量钙镁

采用离子色谱法同时测定白云石中高含量钙镁，该法与目前使用的络合滴定法相比，具有准确可靠、操作简便快速、无干扰等特点。对样品测定取得了满意的结果，氧化钙与镁瓣含量分别为３１．９９％和２１．４７％，相对标准偏差分别为０．８１％和０．６５％，平均回收率分别９９．９％和１０２％。