分散固相萃取净化-超高效液相色谱-串联质谱法测定蜂蜜中双甲脒、杀虫脒及其代谢物

该研究建立了分散固相萃取-超高效液相色谱-串联质谱(dispersive solid phase extraction-ultra-performance liquid chromatography,UPLC-MS-MS)检测蜂蜜中双甲脒、杀虫脒及其代谢物残留的分析方法。蜂蜜样品2 g加入10 mL水溶液充分混匀,经1%(体积分数)氨化乙腈超声辅助提取后离心,利用N-丙基乙二胺、C18、氨基键合硅胶混合材料进行分散固相萃取净化,采用ACQUITY UPLC BEH C18(2.1 mm×50 mm,1.7μm)色谱柱分离,以甲醇和0.1%(体积分数)甲酸水溶液为流动相进行梯度洗脱,多反应监测模式正离子扫描分析。6种农药及其代谢物平均回收率为84.1%~113.8%,相对标准偏差为0.9%~6.0%,检出限为0.2~0.8μg/kg,定量限为0.7~2.5μg/kg。实验结果表明该方法快速简便、灵敏度高,适用于蜂蜜中双甲脒、杀虫脒及其代谢物残留同时分析。

GC/MS法测定茶叶中双甲脒及其代谢物残留量

目的:建立GC/MS法测定茶叶中双甲脒及其代谢物残留量的分析方法。方法:在酸性条件下将双甲脒完全水解成2,4-二甲基苯胺,用正己烷-乙醚混合溶液提取,酸、碱液-液分配净化,通过气相色谱-质谱测定。结果:2,4-二甲基苯胺在0.02~1.00 μg·mL^(-1)线性关系良好,相关系数(R^(2))为0.998 0,加标回收率为81.7%~86.9%,相对标准偏差为1.33%~2.45%,定量限为0.01 mg·kg^(-1)。结论:该方法的实验步骤简单易操作,易于推广,适用于茶叶中双甲脒及代谢物的测定,可为目前茶叶中双甲脒及代谢物的监管提供有效的技术支撑。

GC-MS法测定蜂蜜中双甲脒残留量不确定度评定

目的:利用GC-MS法测定蜂蜜中双甲脒残留量并进行不确定度评定。方法:运用气相色谱-质谱法对蜂蜜中双甲脒残留量进行测定,通过建立数学模型,分析各不确定度来源,对不确定度分量进行评定。结果:双甲脒残留量的不确定度主要由标准溶液的配制过程及样品前处理过程引入。当双甲脒残留量为0.122 4 mg·kg^(-1)时,扩展不确定度为0.008 9 mg·kg^(-1)(k=2)。结论:该方法适用于蜂蜜中双甲脒残留量的不确定度分析,为检验检测数据提供科学可靠的依据。

Determination of Amitraz in the Honey Samples by Dispersive Liquid-Liquid Microextraction Followed by Gas Chromatography—Flame Ionization Detection

Dispersive liquid-liquid microextraction (DLLME) followed by gas chromatography–flame ionization detection (GC-FID), as a simple, rapid and efficient method, was developed for the determination of amitraz in honey samples. This method involves the use of an appropriate mixture of the extraction and disperser solvents for the formation of a cloudy solution in 5.0 mL aqueous sample containing amitraz. After extraction, phase separation was performed by centrifugation and the concentrated amitraz in the sedimented phase was determined by gas chromatography—flame ionization detection (GC-FID). Some important parameters such as the type and volume of extraction and disperser solvents, and the effect of pH and salt on the extraction recovery of amitraz were investigated. Under the optimum conditions (13 μL of carbon tetrachloride as an extraction solvent, 1 mL of acetonitrile as a disperser solvent, no salt addition and pH 6) preconcentration factor and the extraction recovery were 955 and 95.5%, respectively. The linear range was 0.01 - 1.0 mg?kg–1 and the limit of detection was 0.0015 mg?kg–1. The relative standard deviation (RSD, n = 4) for 0.1 mg?kg–1 of amitraz was 3.2%. The recoveries of amitraz from honey samples at the spiking levels of 0.1 mg?kg-1 were 78.8 and 98.2%. The results indicated that DLLME is an efficient technique for the extraction of amitraz in honey samples.

Highly Effective Detection of Amitraz in Honey by Using Surface-Enhanced Raman Scattering Spectroscopy Coupled with Chemometric Methods

As an effective and universal acaricide, amitraz is widely used on beehives against varroasis caused by the mite Varroa jacobsoni. Its residues in honey pose a great danger to human health. In this study, a sensitive, rapid, and environmentally friendly surface-enhanced Raman spectroscopy method (SERS) was developed for the determination of trace amount of amitraz in honey with the use of silver nanorod (AgNR) array substrate. The AgNR array substrate fabricated by an oblique angle deposition technique exhibited an excellent SERS activity with an enhancement factor of -10^7. Density function theory was employed to assign the characteristic peak of amitraz. The detection of amitraz was further explored and amitraz in honey at concentrations as low as 0.08 mg/kg can be identified. Specifically, partial least square regression analysis was employed to correlate the SERS spectra in full-wavelength with Camitraz to afford a multiple-quantitative amitraz predicting model. Preliminary results show that the predicted concentrations of amitraz in honey samples are in good agreement with their real concentrations. Compared with the conventional univariate quantitative model based on single peak’s intensity, the proposed multiple-quantitative predicting model integrates all the characteristic peaks of amitraz, thus offering an improved detecting accuracy and anti-interference ability.

The Formamidine Amitraz as a Hyperglycemic α-Agonist in Worker Honeybees(Apis mellifera mellifera L.)in Vivo

Intra-abdominal injection of amitraz(0.25 nmol per honeybee,i.e.,approx 2.3 nmol/g)to emerging worker bees,in vivo,led to a significant hypertrehalosemia(300-400%)followed by a hyperglucosemia(≈600%).Maxima were reached at 0.5 and 2h,respectively.A strong negative correlation between glucosemia and trehalosemia appeared after injection of pure phentolamine (1 nmol per bee),suggesting stimulation of trehalase activities.Simultaneous administration of the α-blocker at≥0.25 nmol per individual suppressed the hyperglycemic response of amitraz. The formamidine pesticide thus likely acts on the honeybee α-aminergic system.1989 Academic Press,Inc.

Sublethal Effects of the Formamidine Amitraz on Honeybees Gut Lipids, Following in vivo Injections

The time-course and dose-related action of amitraz (AMZ) on gut lipids of worker honeybees were examined over 3 hours following in vivo injections of 0.25, 0.5, 1 and 2 nmols of pesticide per bee. Significant decreases were observed at 30-45 min with 0.25 nmols per bee, for phospholipids, fatty acids, steroids and triacylglycerols. However increases were observed either later or with higher doses. The decreasing action observed with 0.25 nmol AMZ per bee was inhibited by simultaneous injections of the a antagonist phentolamine (from 0.25 to 2.0 nmols per bee). The toxicity of AMZ to honeybees thus likely involves the mobilization of lipids from the gut, via action of this formamidine pesticide on a-adrenoceptors.

双甲脒防治牛疥螨病的试验

为解决牛疥螨病治愈后容易复发、皮下注射应激反应较强的问题,选择1个有27例疥螨病的肉牛场,将其中的21头繁殖母牛随机分成A、B、C三组,6头育肥牛作为对照(D组),4个组的试验牛分别隔离到4个栏内饲养。用水泥填平牛舍墙壁、地面和饲槽等的缝隙,再清扫,冲洗干净。对牛舍环境和牛体均无死角喷淋0.05%双甲脒溶液。其中A组喷淋1次;B组间隔7 d,共喷淋2次;C组每次间隔7 d,共喷淋3次;D组只对牛体喷淋1次,不喷淋环境。结果表明,所有试验牛均在首次喷淋双甲脒后,病灶瘙痒加剧,约持续0.5 h后瘙痒症状缓解,第2天瘙痒症状消失;第7天脱毛的病灶长出新毛,病灶区无蹭痒痕迹;第14天和第21天,所有试验牛均表现出康复状态;第28天,D组中又发现有2个临床病例,全组按A组处理方法再处理1次。在第1次喷淋后的第63天和第126天,所有试验牛只均无疥螨病临床病例。说明预先处理好牛舍墙壁、地面和饲槽等的缝隙,清扫、冲洗后,再用0.05%双甲脒溶液将环境及牛体喷透1次,即可根治肉牛的疥螨病。

The identification of AMZ2 as a candidate causative gene in a severe teratozoospermia patient characterized by vacuolated spermatozoa

Teratozoospermia with cephalic defects is one of the most severe types of sperm defects known to date.While several monogenic factors are linked to cephalic abnormalities,such as globozoospermia and macrozoospermia,the genetic cause of vacuolated spermatozoa remains inadequately described.Here,we analyzed whole-exome sequencing(WES)data for an individual from a consanguineous family with severely vacuolated spermatozoa.The analysis revealed a novel homozygous c.520A>G(p.Thr174Ala)variant in the archaelysin family metallopeptidase 2(AMZ2),a gene that encodes a zinc metalloprotease previously shown to be highly expressed in the testes and sperm.Multiple algorithms predicted this variant to be a damaging mutation.Consistent with an autosomal recessive mode of inheritance,this variant was inherited from heterozygous parental carriers.To investigate the potential pathogenicity of the identified variant,we compared the AMZ2 expression in sperm cells from the patient with the AMZ2 variant and from a healthy control.Immunoblot analysis revealed that the homozygous missense variant in AMZ2 abolished AMZ2 expression in the spermatozoa.Our findings reveal a candidate causative gene for vacuolated spermatozoa.

4种农药对意大利蜜蜂的毒力测定

利用摄入法测定联苯菊酯、溴氰菊酯、双甲脒和氟胺氰菊酯对意大利蜜蜂工蜂的毒性。结果表明,4种农药对意大利蜜蜂工蜂的LC50分别为16.263、62.900、302.784、1001.755mg/L。

蜂蜜中双甲脒残留量检测方法

本文建立了蜂蜜中双甲脒残留量的气相色谱分析方法 ,并对萃取溶剂及衍生化试剂等进行了讨论。蜂蜜中的双甲脒经水解、净化和衍生化后 ,用气相色谱 -电子捕获检测器测定。其回收率为90.5 %～100.1% ,变异系数1.64 %～4.40 % ,最低检测浓度为0.

气相色谱法检测柑桔中痕量双甲脒

本文研究了应用气相色谱法测定柑桔中痕量双甲脒残留物的分析方法。对样品预处理的方法进行探索,最终选择出较为理想的提取试剂,并对定量检测条件作了较详细的研究。

基质固相分散分离——高效液相色谱法测定食物中痕量抗蚜威和双甲脒

研究了应用基质固相分散(MSPD)———高效液相色谱法测定食物中痕量抗蚜威和双甲脒残留物的新方法。并讨论了应用MSPD技术进行前处理与传统残留分析的区别。试验将MSPD技术用于水果、蔬菜中抗蚜威和双甲脒残留物的高效液色谱分析,并对定量检测条件作了详细的研究。

固相微萃取-气相色谱-串联质谱法测定蜂蜜中双甲脒及其代谢产物残留

建立了同时测定蜂蜜中的双甲脒及其代谢产物2,4-二甲基苯胺残留量的固相微萃取-气相色谱-串联质谱法。对固相微萃取的实验条件（萃取纤维、萃取时间、p H值等）进行了选择和优化,并建立了气相色谱-串联质谱（GC-MS/MS）的仪器检测方法。结果表明：在优化的实验条件下,双甲脒和2,4-二甲基苯胺的最低检出限分别为0.5μg/kg和3.0μg/kg;在0.01~1.0 mg/kg的浓度范围内,二者的添加回收率范围分别为81.9%~98.2%和75.5%~90.6%,相对标准偏差分别为5.0%~15.4%和7.9%~17.2%。该方法操作简便、灵敏度高、准确可靠,适用于蜂蜜中双甲脒及2,4-二甲基苯胺的检测。

气相色谱质谱法测定鳗鱼中双甲脒及其代谢物残留量

本文建立了鳗鱼中双甲脒及其代谢产物残留量的气相色谱-质谱检测方法。鳗鱼中残留的双甲脒经水解生成2,4-二甲基苯胺,水解产物用正己烷提取、酸碱液液净化后,用气相色谱-质谱测定。本方法的平均回收率为65.52%～75.95%,变异系数为6.61%～9.38%,最小检测浓度为0.005mg·kg-1,适用于鳗鱼中双甲脒及其代谢产物残留量的测定。

中空纤维液相微萃取-气相色谱法测定水中双甲脒残留

[目的]建立水中痕量双甲脒残留的中空纤维液相微萃取-气相色谱检测方法。[方法]采用中空纤维液相微萃取技术萃取水样中残留的双甲脒,研究萃取剂类型、体积及萃取时间和温度等对萃取效果的影响。[结果]水样中残留双甲脒的最佳萃取条件为:异辛烷为萃取剂,萃取剂体积3μl,搅拌速度600 r/min,30℃条件下萃取15 min;此条件下双甲脒的检出限为1.2μg/L,相对标准偏差为4.9%,富集倍数为85倍;对某河流水样中双甲脒残留进行测定,得加标回收率为93.6%。[结论]中空纤维液相微萃取-气相色谱法检测双甲脒残留具有简单、快捷、准确等优点,能满足水中痕量双甲脒残留的分析测定要求。

双甲脒水解反应的研究

本文对双甲脒在不同pH的缓冲溶液中的水解反应进行了研究.通过测定不同pH值、不同温度下的双甲脒的水解率及反应的表观速率常数,求出了其阿氏活化能,并得出了pH值对水解反应的影响.实验结果表明:水解反应为一级反应,系特殊酸、碱催化反应.此外,结合对水解产物的定量分析,对水解反应中各个可能进行的反应及其机理进行了探讨.

双甲脒与溴氰菊酯、氰戊菊酯混用对麦长管蚜的增效作用研究

利用室内浸渍法测定了双甲脒与溴氰菊酯、氰戊菊酯混用对麦长管蚜 (MacrosiphumavenaeF )的增效作用。溴氰菊酯、氰戊菊酯与双甲脒均以 2∶1比例混合时 ,增效作用最为显著 ;但当溴氰菊酯与双甲脒以 15∶1混用、氰戊菊酯与双甲脒以 1∶10混用时会产生严重的拮抗作用 ,同各单剂分别使用时相比效果明显降低。

桔全爪螨田间种群对双甲脒的敏感性及其两种酶的生化特性

分别对采自重庆市北碚、忠县、万州和长寿四个地区的桔全爪螨雌成螨对双甲脒的敏感性进行了生物测定,其LD50分别为0.014、0.031、0.111和0.007mg/L。同时测定了四个地区桔全爪螨成螨体内羧酸酯酶和乙酰胆碱酯酶的活性,其中羧酸酯酶活性依次为7.78、3.15、6.56和6.00nmol/(min·insect),乙酰胆碱酯酶比活力依次为1.07、0.49、0.50和0.37nmol/(min·mg)。四个地区桔全爪螨体内羧酸酯酶和乙酰胆碱酯酶的动力学常数也存在不同程度的差异。离体抑制作用表明,双甲脒对四个地区桔全爪螨羧酸酯酶和乙酰胆碱酯酶具有明显的抑制作用,当双甲脒浓度达到14.67mmol/L时,抑制作用最强,对北碚、忠县、万州和长寿四个地区桔全爪螨羧酸酯酶的抑制率分别为65.27%、73.84%、81.44%和88.36%,对乙酰胆碱酯酶的抑制率分别为86.84%、84.36%、73.32%和70.85%。