恩诺沙星在余干乌鸡不同组织中的残留消除规律研究

目的 研究恩诺沙星可溶性粉在余干乌鸡各组织内的残留消除规律。方法 88只110d龄健康余干乌鸡,随机分为11组,以0.75 g/L饮水连续给药5 d。停药后第0.16、1、3、5、7、9、20、30、40 d采集肌肉、肝脏、肾脏、皮脂样本,经液相色谱-串联质谱法测定组织中恩诺沙星和环丙沙星残留量,计算药物代谢半衰期,并利用WT1.4软件计算恩诺沙星在余干乌鸡体内的休药期。结果 恩诺沙星在余干乌鸡体内的半衰期和休药期均长于普通肉鸡。恩诺沙星可溶性粉在余干乌鸡肌肉、肝脏、肾脏及皮脂中的休药期分别是110、64、67和208 d。结论 为保证乌鸡产品质量安全和消费者健康,推荐恩诺沙星可溶性粉在余干乌鸡体内的休药期应大于210 d。     

恩诺沙星、氟苯尼考和泰万菌素在鸡蛋中残留消除规律研究

目的 评估恩诺沙星、氟苯尼考和泰万菌素在鸡蛋中的残留消除规律。方法 将80羽高产海兰褐蛋鸡随机等分成4组, 对照组饲喂基础日粮, 恩诺沙星组、氟苯尼考组和泰万菌素组分别经混饲给予相应药物, 每日1次, 连续给药5 d, 停药19 d, 检测各枚鸡蛋中相应药物及其主要代谢产物的残留量。结果 恩诺沙星及其主要代谢产物环丙沙星与氟苯尼考及其主要代谢产物氟苯尼考胺可迅速残留于鸡蛋中, 残留物分别以恩诺沙星原型和氟苯尼考原型为主, 且其残留蓄积期都超过19 d。泰万菌素及其主要代谢产物3-乙酰胺基泰万菌素在鸡蛋中的残留总量低于最大允许残留限量, 且平均残留蓄积期为7 d, 3-乙酰胺基泰万菌素占总残留量的50%以上。结论 恩诺沙星和氟苯尼考在海兰褐品系鸡蛋中残留消除周期超过19 d, 在对后备蛋鸡、肉蛋兼用鸡给药时需严格控制用法用量。在适用情况下, 可优先选择平均残留消除周期相对较短的泰万菌素。     

土霉素、环丙沙星、恩诺沙星在鲫鱼体内残留及消除规律的初步研究

在25±2℃水温条件下,研究土霉素、环丙沙星和恩诺沙星在鲫鱼体内的残留及消除规律。药物在鲫鱼肌肉中的残留用甲醇+水（2+8,pH5.30）提取,反相高效液相色谱法检测,最低检测限可达0.0105mg/kg,平均回收率在80%～95%。研究结果表明:在给定的给药条件下,停药5d后鱼体肌肉的药物浓度达到最大值,停药15d后土霉素和恩诺沙星的残留量降至最大残留限量（MRLs）以下,而环丙沙星的残留仍略高于其MRLs。      

地西泮在鲫鱼不同组织中的残留消除规律研究

目的 掌握地西泮在鲫鱼不同组织中的残留消除规律,合理确定休药期。方法 以鲫鱼为研究对象,用地西泮(初始质量浓度为1.0μg/L)进行药浴,水温控制在(20.0±1.0)℃,分别于给药后的0.5、1、2、3、4、6、8、10、12、24、48、72、96、144、240、288、360、480、600、840、1080、1320 h对鲫鱼肌肉+皮、鳃、肝脏、肾脏、脑、心脏以及血浆等进行检测,探讨鲫鱼不同组织中地西泮药物残留消除规律,并利用WT1.4软件计算地西泮在鲫鱼体内的休药期。结果 地西泮在水产品中的代谢周期较长。肌肉组织的休药期为74 d,鳃的休药期为121 d,肝脏的休药期为174 d,肾脏的休药期为100 d,脑的休药期为78 d,心脏的休药期为45 d,血浆的休药期为106 d.结论 为保证鲫鱼质量安全和消费者健康,建议在养殖温度为20℃时,对鲫鱼单剂量(1.0μg/L)药浴地西泮后的休药期为174 d。     

产前饲喂模式下恩诺沙星在初产蛋中的残留规律及膳食暴露评估

目的 探讨产前饲喂模式下恩诺沙星在初产蛋中残留规律,评估其对鸡蛋的安全性以及消费者健康的影响.方法 选取378只日龄为85 d的海兰褐蛋鸡,根据给药时间分为14组,1.5 g/(kg·BW)恩诺沙星粉剂连续拌料喂药5 d.从给药后生产第1枚鸡蛋开始连续采集鸡蛋8 d,采用液相色谱-串联质谱法分析鸡蛋中恩诺沙星及其代谢产...     

三聚氰胺在罗非鱼体内的残留和消除规律研究

以罗非鱼(Tilapia)为研究对象,通过在罗非鱼饲料中添加不同剂量三聚氰胺进行罗非鱼摄食生长试验,研究三聚氰胺在罗非鱼肝脏和肌肉中的残留和消除规律。实验结果表明:(1)罗非鱼连续饲喂含三聚氰胺的饲料50d,添加不同剂量的三聚氰胺对各组罗非鱼的平均体重增长无显著影响(P>0.05);(2)肝脏和肌肉中三聚氰胺的残留量随着各实验组饲料中添加量的增加呈显著递增趋势(P<0.05),低剂量组(1000、5000mg/kg)的肝脏和肌肉中的残留量在2～20mg/kg间,高剂量组(10000、50000mg/kg)的残留量均超过40mg/kg,各组中肝脏的残留量均显著高于肌肉(P<0.05)。停药5d后,罗非鱼的肝脏和肌肉中三聚氰胺的残留量均内显著下降,各实验组的三聚氰胺残留量均降至2.0mg/kg以下,此后则缓慢下降。各实验组中,肌肉的消除时间比肝脏的消除时间长。     

恩诺沙星及其代谢物在俄罗斯鲟多组织中的 代谢及消除研究

目的研究恩诺沙星及其代谢产物环丙沙星在俄罗斯鲟中的代谢及消除规律,制定恩诺沙星在俄罗斯鲟体内的休药期。方法在水温12～15℃条件下,以60 mg/(kg?bw)剂量对体重为(750±50) g的健康俄罗斯鲟灌服恩诺沙星,灌服后的0～3360 h内不间断采样,使用高效液相色谱-串联质谱仪测定各组织内恩诺沙星及其代谢产物含量。结果灌药后,恩诺沙星在俄罗斯鲟鳃、血浆、肌肉、肝脏、肾脏、皮肤中达峰时间Tmax分别为0.25、9、12、12、18、24 h;肾脏、肝脏、皮肤、肌肉、鳃、血浆达峰浓度Cmax分别为31.863、23.435、21.434、18.640、10.342、2.599 mg/kg;消除半衰期以皮肤最大t1/2为394.431 h、血浆最小为129.6 h。鳃中药物浓度有2个峰值,第1次达峰时,血浆中药物浓度远低于鳃,推测与受试鱼进食习惯或组织结构有关。代谢产物环丙沙星代谢及消除趋势与恩诺沙星大致相同,血浆最早达峰, Tmax为12 h,达峰浓度以肝脏和肾脏较高,Cmax分别为6.876mg/kg和5.648mg/kg。结论从水产品质量安全角度应用本研究结果:以皮肤和肌肉作为可食性组织,恩诺沙星和环丙沙星残留总量不超过0.1 mg/kg至少需要100 d。     

恩诺沙星及其代谢产物在南美白对虾体内药代动力学研究

目的研究恩诺沙星(enrofloxacin,ENR)及其代谢产物环丙沙星(ciprofloxacin,CIP)在虾体内的组织分布和药物代谢随时间的变化规律。方法在(26±2)℃的养殖水温下,以30 mg/(kg·bw)的投喂剂量对南美白对虾进行单次投喂药饵给药,采用高效液相色谱-串联质谱技术(high performance liquid chromatographytandem mass spectrometry,HPLC-MS/MS)进行测定ENR与CIP的含量,其药-时数据通过DAS 2.0动力学软件分析。结果 ENR在南美白对虾体内药时数据符合一级吸收二室模型,而其代谢产物CIP在南美白对虾体内象不符合房室模型。ENR在肝胰腺和肌肉中的最快达峰时间(T_(peak))为1和8 h,达峰浓度(C_(max))分别为24451.2和14212.1μg/kg;药时曲线下面积分别为971766.2和116847.4μg/(L·h);消除半衰期(t1/2β)分别为59.5和33.6 h。CIP在肝胰腺和肌肉中的最快达峰时间(T_(peak))为8和20 h;达峰浓度(C_(max))分别为598.8和4566.6μg/kg。肝胰腺和肌肉的ENR残留量低于最大残留限量(maximum residual limit,MRL)分别为384 h和480 h,而肝胰腺和肌肉中的CIP分别从288和480 h开始低于检出限。结论在(26±2)℃养殖水温下,以30 mg/(kg·bw)剂量对南美白对虾进行单次投饵给药时,建议休药期不得低于20 d。     

Residue concentration of cefquinome after intramammary dry cow therapy and short dry periods

Short dry periods and their effects on milk production, reproductive performance, as well as cow and udder health have been widely studied. A dearth of information is available about the consequences of short dry periods on the residue concentrations of dry cow antibiotics in milk after calving. The objective of our study was to determine the residue concentration of a dry cow antibiotic in milk after short dry periods during the colostrum period and early lactation. Quarters of 19 dry cows were treated with an intramammary (IMM) dry cow antibiotic containing 150 mg of cefquinome on d 21, 14, and 7 before calculated calving date. One quarter of each cow did not receive treatment and served as negative control. After calving, quarter foremilk samples were collected twice daily until 21 d and once daily until 36 d after IMM dry cow treatment (i.e., end of withdrawal period). A total of 588 foremilk samples from odd milking numbers were chosen for the determination of the residue concentration of cefquinome using HPLC–tandem mass spectrometry until the residue concentration fell below the limit of quantification (1 ng/g), which occurred at the latest in milking number 37. The dry period length of the treated quarters was categorized in 3 dry period groups ranging from 1 to 7 d (4.8 ± 2.4), 8 to 14 d (11.5 ± 2.3), and 15 to 26 d (19.5 ± 3.3; ±SEM), in dry period group 1, 2, and 3, respectively. In dry period group 1, the cefquinome concentration increased after calving until the third milking and decreased considerably until the fifth milking. In dry period group 2, the cefquinome concentration peaked at the second milking and decreased considerably until the fifth milking as well. There was no increase in cefquinome after calving in dry period group 3. Up to the 37th milking, the cefquinome concentration was higher in dry period group 1 than in dry period group 2 and 3. On average, 31.3 ± 1.2, 19.0 ± 1.1, and 6.7 ± 0.8 milkings and 19.4 ± 0.4, 20.6 ± 0.5, and 24.1 ± 0.7 d after treatment were necessary for the concentration of cefquinome to fall below the maximum residue limit (MRL) in dry period group 1, 2, and 3, respectively. These results indicate that shorter dry periods lead initially to higher cefquinome residues in milk. The residue concentration after experimental short dry periods still falls below the MRL within the recommended withdrawal period for milk of 36 d after IMM dry cow treatment. For the sake of food safety and economics, these short dry periods should not be used in the dry cow management, as they lead up to a maximum of 31.3 ± 1.2 milkings and 19.4 ± 0.4 d after treatment with cefquinome residues above the MRL. Therefore, a considerable number of milkings have to be discarded due to long withdrawal periods after calving.     

Tissue residue depletion of moxidectin in lambs (Ovis aries) following subcutaneous administration

To date, a tissue depletion study of moxidectin (MOX) in lambs is not available. Thus, considering that lamb meat is of great commercial interest in the world, the aim of the present study was to determine the residue levels of MOX in lamb target-tissues (muscle, liver, kidney and fat) and subsequently calculate the MOX withdrawal period. For this purpose, the target-tissues were analysed by ultra-high-performance liquid chromatography-tandem mass spectrometry. Method validation was performed based on Commission Decision 2002/657/EC and VICH GL49. To quantify the analyte, matrix-matched analytical curves were constructed with spiked blank tissues. The limits of detection and quantitation were 1.5 and 5 ng g^?1, respectively, for all matrices. The linearity, decision limit, detection capability accuracy and inter- and intra-day precision of the method are reported. The lambs were treated with a single subcutaneous dose of 0.2 mg MOX kg^?1 body weight and were slaughtered in accordance with accepted animal care protocols. Samples of target-tissues were collected on 2, 4, 7, 14, 28 and 42 days after MOX administration. During the whole study, the highest drug residue level occurred in the fat. For the other target-tissues (muscle, liver and kidney), MOX concentrations were below the maximum residue limit (MRL). Considering the MRL value of 500 µg kg^?1 for MOX residues in sheep fat, our results in lambs allowed the estimation of a MOX withdrawal period of 31 days. This indicates that the withdrawal period established for MOX in adult sheep (28 days) does not apply for lambs.     

HPLC-MS/MS法同时测定牛肉中80种兽药及其代谢物

为全面排查宁夏地区牛肉兽药残留风险,从农业农村部规定的禁停用药物、 GB 31650—2019《食品安全国家标准 食品中兽药最大残留限量》中规定有最大残留限量的药物以及宁夏养殖环节大量使用药物三方面筛选确定12类药物,利用简单、快捷的前处理方法和超高效液相色谱-串联质谱多反应监测分析技术,建立了一次进样可同时分析检测12类80种兽药及其代谢物残留的快速检测方法。样品采用Oasis PRiME HLB固相萃取柱净化,经Waters HSS T3色谱柱分离,多反应监测模式监测,基质匹配外标法定量。结果表明:80种兽药及其代谢物在基质匹配标准溶液1.0～50.0μg/L的质量浓度范围内呈现良好的线性关系,相关系数均大于0.990,方法定量限在2.0~5.0μg/kg,方法在2.0～100.0μg/kg的平均回收率为60%～103%,相对标准偏差(n=5)均小于20%;应用该检测方法对40份市售牛肉进行检测,其中4份牛肉检出兽药残留,分别为土霉素(54.5μg/kg)、磺胺间甲氧嘧啶(23.3μg/kg和35.4μg/kg)及恩诺沙星(118μg/kg),再分别使用GB/T 21317—2007、GB/T 20759—2006、GB/T 21312—2007方法对阳性样品进行复检,结果一致。经验证表明:该检测方法定性定量结果准确可靠、灵敏度高、重现性好,可满足对牛肉中兽药残留检测分析的要求。     

鱼类恩诺沙星药物残留风险、成因与消减技术研究进展

摘 要: 鱼类恩诺沙星(enrofloxacin, ENR)药残在市场与养殖环境频繁检出, 威胁人类健康与生态安全, 已成为公众日益关注的焦点。研究鱼类ENR药残控制技术对人类与环境可持续发展具有重要意义。本文对鱼类ENR药残现状、生态风险与鱼类ENR药残成因及其与鱼类ENR药效动力学、药代动力学关系进行了综述与分析, 指出最小杀菌浓度给药模式是鱼类与环境ENR药残根源。由此, 从鱼类ENR源头消减角度, 建议开展基于ENR最小抑菌浓度或与无药残中药抗菌剂联合的ENR减量用药研究; 从鱼类ENR药残代谢消除角度,对易于形成ENR药残的鱼类, 建议进行促进鱼类ENR消除的中草药添加剂研究。本文可望为鱼类养殖过程ENR科学用药与水产品药残风险控制研究提供思路。     

高效液相色谱—串联质谱法测定猪可食性组织中烯丙孕素残留

目的:测定猪可食性组织(肌肉、肝脏、脂肪)中烯丙孕素残留。方法:试样经β-葡萄糖醛酸酶/芳基硫酸酯酶酶解,乙腈提取,PRiME HLB固相萃取柱净化。以乙腈—0.1%甲酸水溶液作为流动相,经Waters UPLC BEH C₁₈反相色谱柱分离后于电喷雾正离子模式下检测,基质匹配外标法定量。结果:烯丙孕素在1～50μg/L的质量浓度范围内线性良好,线性相关系数R²>0.99;该方法在猪肌肉、肝脏、脂肪组织中检测限为0.5μg/kg,定量限为1.0μg/kg。在3个添加水平下(1.0,2.0,10.0μg/kg),平均回收率为60.9%～89.8%,日内变异系数为0.8%～7.1%,日间变异系数为2.5%～11.6%。结论:该方法操作简便,适用于猪可食性组织中烯丙孕素残留的定性与定量分析。