鸡蛋中多西环素残留测定不确定度评定

评定了高效液相色谱串联质谱法测定鸡蛋中多西环素残留量的不确定度，通过建立数学模型，对高效液相色谱^-串联质谱法测定鸡蛋中多西环素残留量进行不确定度评定，分析不确定度来源，评价其对测定结果不确定度的相对贡献，并计算合成不确定度，最终得到鸡蛋中多西环素残留量的扩展不确定度。结果显示，鸡蛋中多西环素残留量为9.18μg/kg,在95%的置信区间下，合成不确定度0.0603,扩展不确定度为0.1206(k=2),最终结果应表示为9.18±1.11μg/kg,实验过程中不确定度主要来源于工作曲线的配制过程，测量重复性和回收率。本研究可为以后的检测工作提供可行性建议。     

高效液相色谱法测定牛奶中四环素残留量的不确定度评定

建立了高效液相色谱法测定牛奶中四环素残留量的不确定度评定的数学模型.通过对测量过程中的不确定度来源进行分析与评定,当残留量为85.3 μg/kg时,求得扩展不确定度为5.0μg/kg(k=2).结果表明,标准溶液配制、重复性测量、定容体积和回收率引入的不确定度为测量结果不确定度的主要影响因素.     

液相色谱-串联质谱法测定猪肉中四环素类药物残留量的不确定度评定

评定液相色谱-串联质谱法（LC-MS/MS）测定猪肉中四环素类药物残留量的不确定度。依据GB/T 21317-2007《动物源性食品中四环素类兽药残留量检测方法 液相色谱-质谱/质谱法与高效液相色谱法》,建立相关数学模型,对实验过程中的不确定度来源进行分析与评定。当采用LC-MS/MS法测定猪肉中土霉素、四环素、金霉素、强力霉素的残留量分别为50.05、42.81、42.45、41.60μg/kg时,扩展不确定度分别为 5.44、6.72、2.86、4.80μg/kg (k=2)。检测结果的不确定度主要受回收率、标准溶液配制、工作曲线拟合的影响。     

气相色谱-质谱法测定猪肝中盐酸克仑特罗的不确定度评定

对气相色谱-质谱法(GC/MS)测定猪肝中盐酸克仑特罗残留的不确定度进行评定.通过对测定过程中各变量的分析,确定了不确定度来源,建立了数学模型,计算出了各变量的不确定度,最后计算出合成不确定度.当猪肝中盐酸克仑特罗残留量为5.10 μg/kg时,测定结果的扩展不确定度为0.15 μg/kg(k=2).     

液相色谱法测定饲料中苏丹红残留量的不确定度研究

介绍一种饲料中苏丹红残留量测定的不确定度分析方法。对影响饲料中苏丹红残留量测定不确定度的因素进行分析,包括标准品浓度、体积、样品质量、回收率的重复性等因素,计算得出试验中4种苏丹红(I～IV)测定结果的扩展不确定度分别为0.026、0.060、0.047和0.052mg/kg。     

鱼和虾中组胺残留量HPLC法测定的不确定度评定

利用高效液相色谱法对组胺残留量的检测,建立鱼和虾中组胺残留量的不确定度分析方法,进而对鱼虾中组胺的残留量不确定度进行分析评定。结果表明,HPLC法测定添加水平50 mg/kg的组胺残留量的结果可表示为:X=(48.97±3.98)mg/kg,包含因子k=2。     

高效液相色谱法测定动物性食品中二氯二甲吡啶酚的不确定度评定

运用测量不确定度的基本方法和程序,建立高效液相色谱法测定鸡肝中二氯二甲吡啶酚残留量的测量不确定度评定的数学模型,对测量过程中的不确定因素来源进行分析和量化计算,得出高效液相色谱法测定鸡肝中二氯二甲吡啶酚残留量不确定度结果,当求得鸡肝中二氯二甲吡啶酚的残留量为78.0μg/kg 时,扩展不确定度为3.5μg/kg。     

高效液相色谱-串联质谱法测定鸡肉中癸氧喹酯残留量的测量不确定度评定

分析了影响应用高效液相色谱-串联质谱法测定鸡肉中癸氧喹酯残留量的测量不确定因素,并对各不确定度分量进行了量化计算,最终求得扩展不确定度为0.51礸/kg,分析表明重复测量、制备标准溶液及内标溶液引入的不确定度分量是影响癸氧喹酯残留量测量不确定度的主要因素。     

高效液相色谱-串联质谱法测定鸡肉中癸氧喹酯的测量不确定度评定

分析了影响应用高效液相色谱-串联质谱法测定鸡肉中癸氧喹酯残留量的测量不确定因素,并对各不确定度分量进行了量化计算,最终求得扩展不确定度为0.56μg/kg,分析表明重复测量、制备标准溶液及内标溶液引入的不确定度分量是影响癸氧喹酯残留量测量不确定度的主要因素。     

不同高效液相色谱-串联质谱仪测定猪肉中环丙沙星和恩诺沙星残留量的不确定度评定

评定不同高效液相色谱-串联质谱仪(HPLC-MS)测定猪肉中环丙沙星、恩诺沙星残留量的不确定度。依据GB/T 21312-2007,分别采用Thermo TSQ Quantiva型及Agilent G6470B型高效液相色谱-串联质谱仪测定猪肉中环丙沙星和恩诺沙星残留量,构建评估模型并分析检测过程。结果：当Thermo TSQ Quantiva型测定环丙沙星、恩诺沙星残留量分别为62.91、423.87μg/kg时,其扩展不确定度分别为30.20、36.45μg/kg, k=2;当Agilent G6470B型测定环丙沙星、恩诺沙星残留量分别为61.29、424.87μg/kg时,其扩展不确定度分别为38.00、46.74μg/kg, k=2。结果表明,检测过程的不确定度主要来源于标准工作曲线拟合。且ThermoTSQ Quantiva型测定引入的相对不确定度小于Agilent G6470B测定引入的相对不确定度,更为稳定。     

Problems with malachite green use in fish

The arylmethane dye malachite green oxalate is used as an antimycotic and antiparasitic substance for treatment of fish diseases. The therapeutical use of malachite green is not licensed by the German drug act. A decree fixes a limit of tolerance of 0.01 mg malachite green/kg food produced from fish. A so-called standard license will be prepared for malachite green as a drug for fishes. By trout and carp, malachite green is eliminated slowly. Therefore a long withdrawal time is necessary. The toxicology of the arylmethane dye and the low tolerance to observe in trout and carp is to mind.     

Preliminary investigations of hydrogen peroxide treatment of selected ornamental fishes and efficacy against external bacteria and parasites in green swordtails

The objectives of these preliminary studies were to evaluate the use of hydrogen peroxide (H2O2) for the treatment of selected species of ornamental fishes and its efficacy in treating external bacteria and parasites. In the first part of the study, fish of five species (serpae tetra Hyphessobrycon eques (also known as Serpa tetra H. serpae), tiger barb Puntius tetrazona, blue gourami Trichogaster trichopterus, suckermouth catfish Hypostomus plecostomus, and green swordtail Xiphophorus hellerii) were exposed to H2O2 for 1 h at concentrations between 6 and 34 mg/L or for 24 h at concentrations between 1 and 6 mg/L. The results were species specific: green swordtails tolerated all of the treatments, serpae tetras and tiger barbs were sensitive only to the highest concentration, and mortalities of suckermouth catfish and blue gourami were recorded in every treatment. In the second part of the study, clinically healthy green swordtails and fish infested with external motile rod-shaped bacteria (i.e., Ichthyobodo spp., Trichodina spp., and Gyrodactylus spp.) were treated with several concentrations of H2O2. A single H2O2 treatment of 3.1 mg/L or more for 1 h effectively eliminated external bacteria, concentrations of 6.5 mg/L or more appeared to effectively kill Ichthyobodo spp., and none of the treatments tested was effective against Trichodina spp. or Gyrodactylus spp. These preliminary findings suggest that H2O2 is effective for treating certain external bacterial infections and flagellate infestations in some species of ornamental fish at the dosages tested. Other treatment regimens may need to be tested for effectiveness against Trichodina spp. and Dactylogyrus spp.     

3种蛋白质饲料对雏鹅血清生化指标及激素的影响

选取体重为(78.68±2.95)g的28日龄豁眼鹅300只,采用3处理5重复单因子完全随机设计,研究3%的3种蛋白质饲料(血粉、膨化血粉和鱼粉)对雏鹅血清生化指标及激素的影响。结果显示:1)鱼粉组的ALT、TP、ALB和AST显著高于血粉组(P<0.05),与膨化血粉组差异不显著(P>0.05);膨化血粉组的ALT、TP和ALB与血粉组无显著差异(P>0.05),而AST显著高于血粉组(P<0.05);各试验组间的血清GLOB含量差异不显著(P>0.05)。2)鱼粉组的INS显著高于血粉组和膨化血粉组(P<0.05);鱼粉组的TSH和T3水平显著高于血粉组(P<0.05),但与膨化血粉组相比差异不显著(P>0.05);各试验组的血清GLU、GH、T4和IGF-I水平差异不显著(P>0.05)。研究结果表明,在雏鹅日粮中可用膨化血粉部分取代鱼粉,且其效果要明显优于普通血粉。     

Potential of auxotrophic Edwardsiella tarda double-knockout mutant as a delivery vector for DNA vaccine in olive flounder (Paralichthys olivaceus)

To evaluate potential of an auxotrophic Edwardsiella tarda mutant (Δalr Δasd E. tarda) as a delivery vehicle for DNA vaccine in fish, olive flounder (Paralichthys olivaceus) were immunized with the E. tarda mutant harboring plasmids (pG02-ASD-CMV-eGFP) for eukaryotic expression of the enhanced green fluorescent protein (eGFP) gene through either intraperitoneal (i.p.) or oral route, and the expression of eGFP in the internal organs and generation of antibody against eGFP in fish were analyzed. In fish i.p. injected with 2×10(7)CFU/fish of Δalr Δasd E. tarda harboring pG02-ASD-CMV-eGFP, expression of eGFP was detected in liver, kidney, and spleen from 1 day to 28 days post-injection. In fish orally administered with 1×10(9)CFU/fish of the bacteria, the eGFP band was detected in liver, kidney, and spleen from 1 day to 14 days post-administration, whereas, in intestine, the band was detected only at 1 day post-administration. Either oral or i.p. immunization of olive flounder with recombinant E. tarda that carried eGFP-expressing eukaryotic plasmids was successful to induce humoral adaptive immunity against not only E. tarda that was used as a delivery vehicle but also eGFP that was used as the reporter protein of DNA vaccine, suggesting attenuated E. tarda-vectored DNA vaccine has a potential to be used as a combined vaccine against infectious diseases in fish.     

Growth Performance of Lambs in Phangrang,Vietnam: Effects of a Dietary Supplement Containing Prickly-Pear Cactus

In Phanrang, Vietnam, sheep production is limited by the sparse availability of green roughage. Although prickly-pear cactus (Opuntia elator) is abundant in the area, it is not used. It was considered relevant therefore to test whether prickly-pear cactus could be used a component of feed supplements. With the use of the cactus and other local products--namely groundnut cake, fish sauce by-product, molasses, rice bran and cassava flour--two supplements were prepared. The level of cactus in the two supplements was 670 g/kg product (320 g/kg dry matter). The cactus was burned to remove the spines, chopped and sun-dried before use. The cactus preparation contained only 12 g crude protein/kg (68 g/ kg dry matter). The protein content of the two supplements was raised with either groundnut cake or fish sauce by-product. Sheep that were grazing during the day were offered either no supplement or one of the supplements when confined during the night. During a period of 3 months, non-supplemented control sheep gained 98 +/- 10.5 g/day (mean +/- SD, n=10). Sheep supplemented with cactus and groundnut gained 145 +/- 12.3 g/day, and those given cactus and fish sauce gained 130 +/- 11.7 g/day. It is concluded that prickly-pear cactus has potential as component of feed supplements for sheep.     

配合饲料养蟹对河蟹食用品质的影响

以阳澄湖中围网养殖的投喂冰鲜鱼为主的河蟹为对照,对配合饲料饲养河蟹的安全质量、营养质量和感官指标进行了评价,结果表明,配合饲料饲养的河蟹达到了绿色食品蟹标准NY/T841—2004和无公害食品淡水蟹标准NY5064—2005。全蟹的水分、粗蛋白、粗脂肪含量及肌肉的水分、粗蛋白、粗脂肪、氨基酸含量与阳澄湖蟹也没有显著差异。研究发现,试验组河蟹蒸煮后体色不如阳澄湖蟹,主要原因是池塘中虾青素来源较少,并指出可通过改进配方增强体色。     

Application of peracetic acid for the treatment of juvenile sander (Sander lucioperca) during Ichthyophthirius multifiliis infestation

White spot disease caused by the ciliate protozoan parasite Ichthyophthirius multifiliis (I. m.), is one of the most dangerous diseases in aquaculture and ornamental fish breeding worldwide. The parasite is characterized by three developmental stages: a reproductive tomont, an infective theront and a parasitic trophont. In sander (Sander lucioperca) breeding I. m. causes serious economic losses. After banning of the traditional therapeutic agent malachite green we have to face a state of emergency for the treatment of the ichthyophthiriasis in Germany. The peracetic acid (PAA), characterized by positive therapeutical properties, might close this gap. The purpose of our investigations was the determination of the toxicity of PES to juvenile sander as well as the evaluation of the therapeutic effectiveness of the substance to combat I. m. For juvenile sander (length 3 cm) we determined a 24-h-LC50 of 1.14 (0.97; 1.3) ppm PES. In two investigations PAA was applied in daily intervals of 0.5; 1, 3, 5 and 24 h and concentrations of 0.5; 1; 1.5 and 2 ppm to treat I.-m.-infection in sander. In test I all sander (length 9 cm) died as a result of the I.-m.-infection. However, the PAA exposed fish survived longer than the PES-free controls! This might be due to a disinfection of other pathogens by PAA. In test II, the fish (length 12 cm) were less infected than fish in test I. Four of six fish died in the group exposed with 2 ppm PAA for 24 hours. The abundance of I.-m.-trophonts was determined in mucus, fin and gill tissues of all fish. Significant differences could not be observed between test I and test II because of dissimilar: 1. exposure in time and concentration, 2. age and condition of the fish and 3. homogenity of the variances. Therefore, no therapy strategy was successful while fighting the parasitic trophonts protected by the overlaying fish tissues. We speculate that a successful therapy of I. m. with PAA is, as known e.g. for malachite green, only possible while fighting the free living stages theronts and tomonts. This will be part of our subsequent investigations.     

Treatment of Cyprinus carpio L. and Clarias gariepinus (Burchell) embryos with formalin and malachite green: effect of concentration and length of treatment on their survival.

Malachite green and formalin were investigated as prophylactic dip treatments for developing embryos of Cyprinus carpio and Clarias gariepinus. Based on the findings, recommendations are made on the respective concentrations to be used and exposure periods to be followed for both formalin and malachite green for both fish species.     

Tolerance of benzalkonium chloride, formalin, malachite green, and potassium permanganate in goldfish and zebrafish

OBJECTIVE: To determine tolerance of goldfish and zebrafish to benzalkonium chloride, formalin, malachite green, and potassium permanganate. DESIGN: Tolerance study. ANIMALS: Adult goldfish (Carassius auratus) and zebrafish (Danio rerio). PROCEDURES: Groups of fish (n = 10/group) were exposed to each disinfectant at the therapeutic dosage; at 0.25, 0.5, 3, and 5 times the concentration used for the therapeutic dosage; and at the concentration used for the therapeutic dosage but for 3 or 5 times the recommended exposure time. RESULTS: In both species, exposure to malachite green at the therapeutic dosage resulted in toxic effects, including death. Exposure to formalin at the therapeutic dosage resulted in toxic effects in goldfish, but not zebrafish, and exposure to potassium permanganate resulted in toxic effects in zebrafish, but not goldfish. On the basis of the ratio of therapeutic dosage to median lethal dosage, in goldfish, formalin was more toxic than benzalkonium chloride, which was more toxic than malachite green, which was more toxic than potassium permanganate. In zebrafish, potassium permanganate was more toxic than formalin and benzalkonium chloride, which were approximately equally toxic and more toxic than malachite green. Extending treatment time increased the toxicity of potassium permanganate in zebrafish and the toxicity of formalin and malachite green in goldfish, but did not alter the toxicity of the other disinfectants. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that there was no consistency between zebrafish and goldfish in their tolerance to disinfectants, and that therapeutic dosages reported in the literature for these disinfectants were not always safe.     

Algal dermatitis in cichlids

Three varieties of a popular African cichlid aquarium species, Pseudotropheus zebra, from 2 tropical fish farms in east central Florida were submitted for diagnostic evaluation because of the development of multifocal green lesions. The percentage of infected fish in these populations varied from 5 to 60%. Fish were otherwise clinically normal. Microscopic examination of fresh and fixed lesions confirmed algal dermatitis, with light invasion of several internal organs in each group. A different alga was identified from each farm. Fish from farm A were infected with Chlorochytrium spp, whereas fish from farm B were infected with Scenedesmus spp. Because of the numbers of fish involved, bath treatments to remove the algae from affected fish from farm B were attempted, with different dosages of several common algaecides including copper sulfate pentahydrate, diuron, and sodium chloride. However, none of these treatments were successful, possibly because of the location of the algae under the scales and within the dermis, and also because of the sequestering effect of the granulomatous response. To our knowledge, this is the first report of algal dermatitis in ornamental cichlids, as well as the first report of Scenedesmus spp infection in any fish.