高效液相色谱法测定家兔肌肉及组织中土霉素、四环素的残留量

用高效液相色谱(High performance liquid chromatography,HPLC)法测定家兔腿肌、心、肝、肾等组织中土霉素、四环素残留量。色谱柱为Hypersil BDS,以乙睛-3%冰乙酸水溶液(30∶70)为流动相,检测波长为350 nm,柱温30℃。结果表明:土霉素、四环素标准品浓度在8.2~262.5μg/mL范围内线性关系良好,土霉素线性方程为Y=19392.82X-22.90,r=0.99948;四环素线性方程为Y=14089.84X-33.34,r=0.99888。家兔肝脏的土霉素加样回收率平均为89.1%,RSD=2.03%;四环素加样回收率平均为91.1%,RSD=2.22%。说明HPLC法准确可靠,为监控兔产品土霉素、四环素残留提供了安全、方便的检测手段。     

Oxytetracycline (OTC) accumulation and elimination in hemolymph, muscle and hepatopancreas of white shrimp Litopenaeus vannamei following an OTC-feed therapeutic treatment

The white shrimp, Litopenaeus vannamei, has become a very important species for the development of shrimp aquaculture in Northwest Mexico. However, viral and bacterial diseases are considered a major threat to the development of this industry. In the present study a trial was conducted to evaluate the tissue distribution, maximum concentration, and elimination of the widely used antibiotic oxytetracycline (OTC) in L. vannamei using indoor tanks under laboratory-controlled conditions. OTC was given to shrimp simulating a therapeutic treatment through medicated feed for 14 days followed by a period of feeding without antibiotic for another 14 days to evaluate the elimination pattern. Samples of hemolymph, muscle, and hepatopancreas were taken from medicated animals every two days for 28 days. All tissues were removed and frozen immediately in liquid nitrogen. OTC levels were analyzed by High Performance Liquid Chromatography (HPLC). Results showed an important OTC increase during consumption of medicated feed in all examined tissues. OTC maximum concentrations were 33.54 ± 11.19, 194.37 ± 16.11, and 18.79 ± 5.87 µg g^− 1 for muscle, hepatopancreas and hemolymph, respectively. Although the highest OTC level was found in the hepatopancreas, it required only two days after the start of dosing to reach this value, whereas the maximum OTC for muscle and hemolymph was detected after eight days of dosing. Ten days after the cessation of medicated feeding, the drug content in the shrimp tail muscle was under the detectable limit for the method (0.01 µg g^− 1 of OTC).     

土霉素对土壤微生物群落结构和酶活性的影响

模拟了土壤环境中土霉素暴露对微生物群落结构和酶活性的影响。结果表明,土霉素的施加明显改变了土壤微生物群落结构,细菌和放线菌数目明显降低,抑制作用一直持续近30d,而对真菌的影响不明显。通过对土壤中碱性磷酸酶,酸性磷酸酶,脱氢酶和脲酶的跟踪检测,发现仅碱性磷酸酶受土霉素的影响较大。     

复方土青注射液制备方法及疗效试验

试验用土霉素二水合物、青蒿素、氟尼辛葡甲胺和甲氧苄啶制成了复方土青注射液,并进行了鉴别、含量、稳定性、安全性等测定。所制成的注射液,经肌肉注射,治疗敏感的革兰氏阳性菌、阴性菌、支原体、立克次氏体及衣原体等感染性疾病,疗效极显著,平均治愈率为94.89%,比土霉素注射液平均治愈率提高67.83%。     

(010)晶面暴露的Bi2MoO6纳米片对土霉素和四环素的可见光催化降解

以(010)晶面暴露的Bi2MoO6纳米片作为光催化剂,通过改变溶液pH值、催化剂用量及目标降解物的初始浓度等考察Bi2MoO6纳米片对土霉素(Oxytetracycline,OTC)和四环素(Tetracycline,TC)在可见光下降解效果的影响;通过加入不同的自由基清除剂来考察光催化过程的机理。结果表明:光催化剂对OTC和TC的降解效果会因其在溶液中的存在形式不同而改变,随着溶液pH值的升高OTC与TC会发生逐级电离。在最佳pH值(pH=11)条件下,可见光辐照1h后,OTC与TC分别降解42.1%和58.8%(催化剂质量浓度为1.4g/L)。OTC和TC的光催化降解动力学研究表明,其降解过程符合伪一级动力学方程,其降解动力学常数分别为0.006 64min-1和0.008 45min-1。光催化降解机理的研究表明,空穴是主要的活性物质,其原因可能是在pH值为11时,大量的OTC和TC被吸附在光催化剂表面,有利于光生电子从光催化剂迁移至目标降解物。     

土霉素和乳酸依沙吖啶联合用药对奶牛子宫内膜炎的治疗试验

为探究土霉素和乳酸依沙吖啶联合应用在治疗奶牛子宫内膜炎中的疗效,选取豫北一个中型牧场63头患有子宫内膜炎的奶牛进行试验,将其随机分为三组,每组21头。第一组只用土霉素溶液;第二组用土霉素＋乳酸依沙吖啶的水溶液;第三组只用乳酸依沙吖啶溶液。每组均按3次送药为一个疗程进行子宫内灌注。结果显示,第一组奶牛用药一个疗程的治愈率和有效率分别为38．1％、66．7％,两个疗程的总治愈率和总有效率分别为61．9％、85．7％;第二组奶牛用药一个疗程的治愈率和有效率分别为47．6％、85．7％,两个疗程的总治愈率和总有效率分别为81.0％、95．2％;第三批奶牛用药一个疗程的治愈率和有效率分别为23．8％、47．6％,两个疗程的总治愈率和总有效率分别为38．1％、61．9％。结果表明,土霉素和乳酸依沙吖啶联合用药治疗奶牛子宫内膜炎的效果十分显著。     

连续性循环式活性污泥法在土霉素类制药废水处理中的应用

采用微电解法对土霉素类废水进行预处理 ,再经连续性循环式活性污泥处理土霉素类高浓度有机废水 ,进水的CODcr浓度在 5 30 0mg·L-1以下时 ,经过系统的处理处理后 ,CODcr降解率达 97.6 %.出水的各种指标达到了国家规定的排放标准 .     

基于响应面法的土霉素高产菌株S189发酵培养基优化

[目的]提高龟裂链霉菌S189土霉素发酵效率,对其发酵培养基进行优化。[方法]通过PB试验,对培养基中影响发酵效率的各因素进行评价,筛选出显著因素,进一步通过最陡爬坡试验确定其较优浓度,最后利用中心组合试验设计方法结合响应面分析方法,确定3个因子的最佳浓度。[结果]PB试验结果表明,黄豆饼粉、玉米浆和碳酸钙对发酵效率有较大影响。响应面试验优化后这3个因素的最佳含量为:黄豆饼粉41.0 g/L,玉米浆16.4 g/L,碳酸钙12.8 g/L。采用优化后的培养基进行摇瓶发酵,发酵单位可达29.8 mg/L,比优化前提高了24.3%。[结论]响应面方法可用于土霉素发酵培养基的优化,该研究有利于提高土霉素发酵效率。     

土霉素菌渣活性炭对亚甲基蓝吸附的研究

[目的]研究土霉素菌渣活性炭对亚甲基蓝的吸附.[方法]以土霉素菌渣活性炭为吸附剂,研究了pH、吸附温度及转速对土霉素菌渣活性炭吸附亚甲基蓝效果的影响,并采用准一级方程和准二级方程模型对反应动力学数据进行拟合.[结果]随着pH的增大,吸附量增大;吸附温度为35 cc时吸附量最大;转速为150 r/min时吸附量最大;准二级反应动力学模型能够较好地描述土霉素菌渣活性炭对亚甲基蓝的吸附动力学数据.[结论]该研究可为土霉素菌渣活性炭吸附亚甲基蓝废水的科学研究和合理利用提供科学依据.     

Development of lipid microbeads for delivery of lipid and water-soluble materials to Artemia

Lipid spray beads (LSB) containing high concentrations of phospholipids were produced in order to improve their dispersion in both fresh and saltwater. The beads were developed to deliver both fat-soluble and water-soluble micronutrients to Artemia and other suspension feeders. LSB were prepared by spraying molted lipid into a chamber that was cooled with liquid nitrogen in order to solidify the lipid beads. Addition of soy lecithin to LSB did not affect retention of glycine when the beads were suspended in distilled water. There was an initial loss of 80% incorporated glycine after LSB were suspended in water for 20min. Artemia readily ingested riboflavin-containing LSB and their full guts were evident within 30min of feeding. The riboflavin content of Artemia could be increased from 55 ±  0.6 mg kg^− 1 (dw) to 329 ± 62 mg kg^− 1 (dw) after 1h enrichment. LSB prepared with phospholipids are promising vehicles for enrichment of suspension-feeding organisms used as feed for larval marine fish and crustaceans as well as other suspension feeders.