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71.
为建立牛奶及奶粉中5种苯并咪唑类药物(阿苯达唑、芬苯达唑、奥芬达唑、噻苯达唑、苯硫氨酯)简便、准确的分析检测方法,以固相萃取为净化手段,采用Acquity UPLC® BEH C18(100 mm×2.1 mm,1.7 μm)色谱柱进行分离,电喷雾离子源(ESI+),多反应监测(MRM)模式检测。结果表明,5种苯并咪唑类药物在1~500 μg·L-1范围内呈线性相关,相关系数(r)均大于0.996,加标平均回收率介于91.7%~97.8%之间,相对标准偏差(RSD)在1.4%~6.5%之间,基质效应均小于15%。5种药物的检出限均在0.1~3 μg·kg-1范围内,定量限均在0.5~10 μg·kg-1范围内。该方法操作简单、快速且灵敏度高,重现性好,能够用于牛奶及奶粉5种苯并咪唑类药物的同时测定。  相似文献   
72.
2018年,在湖南的长沙和张家界、浙江兰溪等12个地点开展除虫脲的最终残留试验,并在湖南长沙、江西高安、广西南宁、福建漳州等4地进行除虫脲的残留消解动态试验,采用高效液相色谱–串联质谱法(HPLC–MS/MS)测定除虫脲在柑橘全果和果肉中的残留量,并进行除虫脲的膳食安全风险评估。柑橘样品先采用乙腈超声提取,再经PSA和无水硫酸镁净化,最后用HPLC–MS/MS分析测定,外标法定量,柑橘全果和果肉中除虫脲的添加水平为0.01、0.10、1.00、5.00mg/kg时,平均回收率分别为89%~102%和76%~99%,相对标准偏差分别为7%~11%和8%~9%;除虫脲在柑橘全果和果肉中的定量限均为0.01 mg/kg;除虫脲在柑橘全果和果肉中的残留量随着时间的推移呈波动性缓慢下降,其消解半衰期分别为13.0~18.0 d和9.6~34.0 d;质量分数25%除虫脲可湿性粉剂在柑橘上以125 mg/kg(制剂用量为2000倍液)施药3次,施药间隔7 d,于末次施药后第35天采样测定,除虫脲在柑橘全果和果肉中的残留量分别为<0.01~0.55 mg/kg和<0.01~0.93 mg...  相似文献   
73.
同位素稀释液质联用法测定鱼体中氯丙嗪的残留   总被引:1,自引:0,他引:1  
建立了高效液相色谱-串联质谱(HPLC/MS/MS)分析鱼体中氯丙嗪残留的方法.样品用乙腈提取,MCX固相萃取柱净化,氨化甲醇洗脱.在正离子模式下以电喷雾串联质谱仪进行测定,采用内标法定量,氘代氯丙嗪为内标物.以欧洲鳗鲡、鳜鱼和大口黑鲈为研究对象,在1.0、5.0、25.0μg/kg添加水平下,方法平均回收率为90.1...  相似文献   
74.
分别取罗非鱼(Oreochromis niloticus)的肉、脂肪、肝、眼和皮等组织,用氯仿-甲醇(2∶1,v/v)提取,以C17∶0为内标物,利用气相色谱-质谱法(GC/MS)分析了各组织脂肪酸种类及含量。结果显示:罗非鱼各种组织中含有16种脂肪酸,富含多不饱和脂肪酸。脂肪组织中的脂肪酸含量最高,其次是眼睛、肝脏、鱼肉和鱼皮;各组织中饱和脂肪酸(SFA)含量为202~8869 mg/kg,主要为棕榈酸(C16∶0)和硬脂酸(C18∶0);单不饱和脂肪酸(MUFA)含量为293~11219 mg/kg,主要为棕榈油酸(C16∶1)和油酸(C18∶1);多不饱和脂肪酸(PUFA)含量为362~8293 mg/kg,主要是亚油酸(C18∶2)、亚麻酸(C18∶3)和二十二碳六烯酸(DHA,C22∶6);n-6/n-3为1.20~2.46。  相似文献   
75.
Abstract – Strontium/Calcium (Sr/Ca) and Barium/Calcium (Ba/Ca) ratios were measured in 60 otoliths of the French Polynesian flagtail Kuhlia malo. Both elemental ratios were needed to correctly distinguish residence in marine, brackish and fresh water. High Sr/Ca and low Ba/Ca around the nucleus of all otoliths provided evidence of marine residency during the early life of all individuals. At about 0.5 mm from the core, Ba/Ca increased rapidly and remained high in all otoliths. High and unstable Sr/Ca ratios were attributed to estuarine residency, whereas low and stable Sr/Ca ratios were attributed to freshwater residency. These chemical signatures inferred that following recruitment to rivers, some fish remained in the estuary, while others moved upstream. Some individuals shared their time between fresh and brackish waters later in life. The findings of this study have important implications for the protection of nearshore, brackish and freshwater environments for the conservation of this French Polynesian diadromous species.  相似文献   
76.
以水溶液体系作为对照,利用分光光度法研究了W/O型微乳液体系中水杨酸(SA)和水杨酸甲酯(MS)清除超氧阴离子自由基(·O2-)的性能.结果发现,在水浴时间为20min、pH值为8.20和邻苯三酚加入量适宜的情况下,W/O微乳液体系中SA、MS对·O2-的清除率分别可达72.92%、81.47%.微小的pH值变化会引起邻苯三酚自氧化速率的显著变化,电解质溶液对其也有明显的影响,但对SA、MS清除·O2-的能力影响不大.  相似文献   
77.
Dissipation of dithiopyr in soil was monitored after application to wheat crop as pre- or post-emergence applications at two rates, viz 100 and 200 g AI ha(-1). The level of dithiopyr in the soil was assessed by gas chromatography, and its disappearence was found to follow a first-order decay curve irrespective of rate or method of application. The half-life in soil ranged between 17.3 and 25.0 days and residues at harvest (150 days after application) ranged between 4.0 and 8.8% of amounts applied. Investigation of microbial degradation of dithiopyr was conducted in minimal salt and Czapek Dox media in which 80% of the compound degraded within 15 days. Residues were not detected in wheat grain at harvest.  相似文献   
78.
牛奶中吡利霉素残留检测高效液相色谱-串联质谱法研究   总被引:2,自引:0,他引:2  
建立了牛奶中吡利霉素残留检测的高效液相色谱-串联质谱(HPLC-MS/MS)法。液相色谱条件为:色谱柱为Waters XBridge C18柱(150 mm×2.1 mm,5μm),流动相为乙腈-0.01mol/L乙酸铵溶液(30∶70,V/V),柱温为30℃,流速为0.2 mL/min,进样量为10μL。质谱条件为:电喷雾离子源(ESI ),多反应监测(MRM)方式进行采集;监测离子质荷比(m/z)为411.5>112.0,411.5>363.4。以吡利霉素的同分异构体异吡利霉素作内标,内标法定量。结果表明:吡利霉素的线性范围为20~400 ng/mL,相关系数R2=0.999 9;方法检测限为2 ng/mL,定量限为5ng/mL;从50、100和150 ng/mL三个添加浓度检测结果可以看出,方法的平均回收率为90.4%~104.3%(n=6),批内、批间RSD均小于5%。  相似文献   
79.
Extra-cellular enzyme production of different Phaeoacremonium spp. and Phaemoniella chlamydospora isolates were used to assay the possibility of inter-specific characterisation. Isolates of Phaeoacremonium aleophilum, Phaeoacremonium angustius, P. viticola and Ph. chlamydospora were grown on solid media and the activities of extra-cellular amylases, lipases, proteases, cellulases, xylanases, laccase, polygalacturonase, pectate lyase, lignin peroxidase, manganese peroxidase, urease and chitinase were assayed. Phaeoacremonium species showed activities of a larger number of enzymes and also enzyme activity was frequently higher suggesting that Phaeoacremonium can be more virulent. To assay if the produced extra-cellular enzymes could reflect the virulence capacity of the two genera, calluses of Vitis vinifera L. (cvs. Baga and Maria Gomes) and of a rootstock (R3309) were inoculated with filtrated culture liquid medium of three isolates of Ph. chlamydospora and one of P. angustius. Filtrates from all strains decreased callus growth and membrane integrity, while soluble protein content of calluses decreased with the strains CAP 054 and 1AS. P. angustius (CAP 054) induced the more severe symptoms in all genotypes. Water content decreased together with an increase of osmolality in both cultivars but not in rootstock suggesting that osmorregulatory capacity is more affected in cultivars. Data show that: (1) Phaeoacremonium and Phaeomoniella genera have different patterns of extra- cellular enzymatic production; (2) these fungi produce extra-cellular compound(s) that induce(s) senescence symptoms in plant cells inhibiting callus proliferation; (3) among the strains tested in plant calluses the most virulent isolate (CAP 054) also produced higher amounts of some extra-cellular enzymes; (5) rootstock calluses were less sensitive to inoculation than grapevine calluses.  相似文献   
80.
The present study focuses on hybridization program involving two species belonging to two different vandaceous genera, viz., Ascocentrum ampullaceum (Roxb.) Schltr. var. auranticum, a narrow endemic orchid of Manipur and Vanda coerulea Griff., an endangered orchid of Appendix I of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora), to synthesize the primary hybrid genus with intermediate and improved characters in the F1 generation. Observations on the crossability in the present bigeneric cross between V. coerulea and A. auranticum had been achieved with 60% success when V. coerulea was taken as female parent. Murashige and Skoog (MS) basal medium at half-strength was effective for the development of the hybrid seedlings of V. coerulea × A. auranticum followed by Vacin and Went (VW) and Knudson C (KC) media. The best response of seedling growth was observed on MS medium at half-strength supplemented with 2.3 μM kinetin + 0.5 μM α-naphthalene acetic acid with maximum shoot height (2.7 cm), leaf number (4.6) and root number (4.1) after 150 days of inoculation. The survival percentage and growth performance of the seedlings were found to be higher (80% survival) in potting substrate consisting of brick:charcoal in the ratio 2:1 mulched with moss (Sphagnum sp.) than in potting substrate consisting of brick:charcoal:tree fern in the ratio 2:1:1. The first flowering was observed in the hybrid seedlings of V. coerulea × A. auranticum after 2 years of transfer to the ex vitro environment. Morphologically, the flowers differed from that of the parents clearly showing the success of the hybridization experiment. Registration of the hybrid has been made with the Royal Horticultural Society with the nomenclature Ascocenda ‘Kangla’ (No. T128725).  相似文献   
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