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1.
电位滴定法测定饲料添加剂碘化钾含量   总被引:1,自引:0,他引:1  
饲料级碘化钾,作为饲料中碘的补充剂广泛应用于饲料生产中,其含量的测定现行方法为GB8256。该法用曙红钠作为指示剂,以终点时产生肉红色吸附物来指示终点。但因指示剂本身带有的浅红色与滴定过程中不断生成的碘化银黄色沉淀叠加形成的背景色与终点向红色相近,给准确判别终点带来一定困难,易造成滴定误差。而银电极电位滴定法有专一性好,不受样品色泽限制,无终点判别等而日益为人们所青睐,尤其是有条件时,求得终点电位值(Ev)后的固定电位滴定法(自动电位滴定法)更显简便。为此,本文在求得终点电位值(EV)后,实测了商品饲料…  相似文献   

2.
自动电位滴定法测定饲料中水溶性氯化物   总被引:1,自引:0,他引:1  
“GB6439—86”标准规定的沉淀滴定(莫尔)法是目前饲料行业测定饲料中水溶性氯化物较常用的方法。此法是根据生成铬酸银砖红沉淀来指示终点。但饲料样液大多浑浊有色,准确判别终点有一定困难,易产生较大滴定误差。自动电位滴定法则是根据滴定过程中电极电位的突跃代替指示剂来指示终点,只需求一次终点电位,即可对批量样品实现自动滴定,操作简便快速,滴定误差小,能获得较满意的测定结果。  相似文献   

3.
建立了氧瓶燃烧-电位滴定法测定盐酸头孢噻呋中氯含量的方法。通过氧瓶燃烧法将盐酸头孢噻呋中氯转化成无机形态的氯,再通过电位滴定法定量分析吸收液中的氯含量。该方法的回收率在99.0%~105.0%之间,回收率符合要求。元素分析法测定的氯含量与氧瓶燃烧-电位滴定法测定的氯含量相一致。该方法适用于水溶性差的药物中氯含量的测定。  相似文献   

4.
建立了一种基于自动电位滴定技术的脐橙叶片中氯含量的快速检测方法。该法采用稀硝酸浸提脐橙叶片中氯,然后用自动电位滴定法快速测定溶液中氯含量,并考察了方法的测定条件、精密度和准确度。该方法的检出限为0.6249mg/L,加标回收率为94.85%~102.96%,相对标准偏差小于3.0%,故该法适于脐橙叶片中氯含量的快速分析。  相似文献   

5.
施远国 《广东饲料》2007,16(2):41-42
用电位滴定法测定饲料级赖氨酸盐酸盐标准物质的含量,回收率为99.6%;同时用该法与GB8245-87《饲料级L-赖氨酸盐酸盐》进行比对,两者测定结果无显著性差异。  相似文献   

6.
分别用PAN、二甲酚橙、紫脲酸铵作为指示剂,研究了EDTA配位滴定法测定羟基蛋氨酸铜螯合物中铜含量的方法,标准偏差均小于0.2%,相对标准偏差小于0.6%。结果表明,EDTA配位滴定法测定羟基蛋氨酸铜中铜含量,操作过程简单、方便,分析结果重现性好、准确度高,且三种指示剂均可用于铜的测定,其中紫脲酸铵最好,终点变色敏锐。本法可用于不同工艺所合成的羟基蛋氨酸铜中铜含量的测定。  相似文献   

7.
微胶囊化氟苯尼考的含量测定方法   总被引:1,自引:0,他引:1  
采用改良电位滴定法测定微胶囊化氟苯尼考的含量,回收率达99.9%,相对标准偏差(尺SD)为0.74%,这表明改良电位滴定法是测定微胶囊化氟苯尼考的可靠方法.  相似文献   

8.
对氟苯尼考含量两种测定方法即电位滴定法和高效液相色谱法进行比较分析。采用HPLC法测定氟苯尼考在5~100μg/ml范围内呈良好的线性关系(r2=0·99998),平均回收率为99·6%,RSD为0·3%。采用电位滴定法测定氟苯尼考含量偏低,回收率仅为91·4%,RSD为0·4%。结果表明采用HPLC法测定氟苯尼考,与杂质分离度好,操作简便,结果更精确。  相似文献   

9.
依据GB 5009.44—2016《食品安全国家标准 食品中氯化物的测定》,对特殊医学用途婴儿配方食品中氯的检测方法适用性展开研究。结果表明:采用GB 5009.44—2016第三法(银量法)检测特殊医学用途婴儿配方食品中乳蛋白部分水解配方、乳蛋白深度水解配方、氨基酸配方得到的样品加标回收率分别为95%~108%、98%~125%、100%~106%,相对标准偏差为12.7%~32.9%;采用GB 5009.44—2016第一法(电位滴定法)得到的检测结果低于第三法检测结果。  相似文献   

10.
研究旨在比较分析不同氧化镁检测方法,探讨不同方法对饲料添加剂氧化镁含量检测结果的影响。研究比较分析EDTA滴定法、酸碱滴定法和电位滴定法对饲料添加剂氧化镁含量检测结果的影响,同时通过改进样品前处理条件,进而改进饲料添加剂氧化镁检测方法。结果显示:EDTA滴定法的检测结果显著高于酸碱滴定法和电位滴定法,电位滴定法的检测结果最低,且平行样间绝对差大,不符合试验检测要求。综上可得,采用EDTA滴定法检测饲料添加剂氧化镁含量,结果准确、操作简单快捷且检测成本低,适用于生产检测。  相似文献   

11.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

12.
Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.  相似文献   

13.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

14.
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.  相似文献   

15.
The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.  相似文献   

16.
17.
An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.  相似文献   

18.
Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein  相似文献   

19.
正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in  相似文献   

20.
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