urea - Names and Identifiers
urea - Physico-chemical Properties
Molecular Formula | CH4N2O
|
Molar Mass | 60.04 |
Density | 1.335 |
Melting Point | 131-135℃ |
Water Solubility | 1080 g/L (20℃) |
Solubility | Soluble in water, ethanol and benzene, almost insoluble in ether and chloroform. |
Appearance | Colorless crystal |
Storage Condition | 2-8℃ |
Sensitive | Easily absorbing moisture |
Refractive Index | 0 |
MDL | MFCD00198123 |
Physical and Chemical Properties | density 1.335 melting point 131-135°C water-soluble 1080g/L (20°C)
|
Use | Used as fertilizer, animal feed, explosives, stabilizers and urea-formaldehyde resin and other raw materials |
urea - Risk and Safety
Safety Description | S24/25 - Avoid contact with skin and eyes.
|
urea - Upstream Downstream Industry
urea - Reference
Reference Show more | 1. Tian Jing Jin Hua Shen Guo An et al. Effects of 6-BA and urea on the formation of root buds of epimedium mimetic [J]. Modern Chinese medicine, 2019, 21(01):71-75. 2. Lin Liyun, Dong Xiaojie, Chen Awei. Extraction and activity determination of soybean urease [J]. Food Research and Development, 2013, 000(009):85-87,88. 3. Chen Shanglong, Liu Enqi, Chen Anhui, et al. Preliminary analysis of selenium speciation and bioavailability in two selenium-enriched products using in vitro biomimetic model [J]. Food Science, 2018, 039(004):225-232. 4. Chen Shanglong, Chen Anhui, Liu Hui, etc. Analysis of the effect of yogurt fermentation on calcium speciation by using digestive system full bionic model [J]. Journal of Agricultural Engineering, 2018, v.34;No.332(05):297-302. 5. Wei Bin, Hu Xueqing, Song Yanan, etc. Metabolomics study of "different diseases with the same syndrome" after colorectal cancer and liver cancer surgery [J]. World Science and Technology-modernization of traditional Chinese medicine, 2016, 18(9):1500-1506. 6. Hong Zehan, Wu Wanyi, Li Lu, et al. Comparison of in vitro digestion of lycopene nanoemulsions constructed with different macromolecular emulsifiers [J]. Food Science, 2019, 40(10):9-15. 7. Qian Weidong, Fu Yunfang, Hu Na. Study on fermentation conditions of lactase production by Klyveromyces lactis yeast [J]. Chinese agricultural bulletin, 2012. 8. Zhiheng. Study on the construction and adhesion mechanism of foliar adhesive pesticide delivery system [D]. Chinese Academy of Agricultural Sciences, 2020. 9. Zhang Xifeng, Wang Xinxin, Zhang Qingting, Luo Guanghong. Separation of polysaccharide from oil peony seed meal by temperature-sensitive aqueous two-phase system with low eutectic solvent [J]. China Oils and fats, 2020,45(12):93-99. 10. Zhao Shaojie. High-value utilization of multi-sugar-based resources in citrus peel [D]. Chinese Academy of Agricultural Sciences, 2020. 11. Cheng, Qi-Bin, and Li-Wei Zhang. "High efficient inductive preparation of daidzein deep eutectinib solvents." Molecules 22.1 (2017): 186.https://doi.org/10.3390/molecules22010186 12. Lizhen Liu, Zhi Mi, Ziying Guo, Junling Wang, Feng Feng,A label-free fluorescent sensor based on carbon quantum dots with enhanced sensitive for the determination of myricetin in real samples,Microchemical Journal,Volume 157,2020,104956,ISSN 0026-265 13. Yinghao Duan, Shuo Li, Sheng Lei, Yuanyuan Xu, Lina Zou Baoxian Ye,A new voltammetric sensor based on reduced graphene oxide loaded flower-like Bi2O2CO3 film for sensitive determination of urapidil,Journal of Electroanalytical Chemistry,Volume 820,201 14. [IF=4.464] Yinghao Duan et al."A new voltammetric sensor based on reduced graphene oxide loaded flower-like Bi2O2CO3 film for sensitive determination of urapidil."J Electroanal Chem. 2018 Jul;820:132 15. [IF=4.411] Qi-Bin Cheng et al."Highly Efficient Enzymatic Preparation of Daidzein in Deep Eutectic Solvents."Molecules. 2017 Jan;22(1):186 16. [IF=13.273] Xin Ji et al."Developing visible light responsive Z-scheme BN-PDI photocatalysts with good degradation performance for antibiotics."Chem Eng J. 2021 Dec;425:131260 17. [IF=10.588] Yong Guo et al."UV-light promoted formation of boron nitride-fullerene composite and its photodegradation performance for antibiotics under visible light irradiation."J Hazard Mater. 2021 May;410:124628 18. [IF=6.953] Ying Liao et al."An eco-friendly NP flame retardant for durable flame-retardant treatment of cotton fabric."Int J Biol Macromol. 2021 Sep;187:251 19. [IF=4.952] Wei Chen et al."Structure and emulsifying properties of whey protein isolate: Effect of safflower yellow concentration."Lwt Food Sci Technol. 2020 Apr;123:109079 20. [IF=4.952] Xiaoyan Liu et al."Correlation analysis of microbial communities and precursor substances of ethyl carbamate (EC) during soy sauce fermentation."Lwt Food Sci Technol. 2021 Dec;152:112288 21. [IF=4.952] Yuan Zou et al."Physicochemical and emulsifying properties of protein isolated from Phlebopus portentosus."Lwt Food Sci Technol. 2021 May;142:111042 22. [IF=4.821] Lizhen Liu et al."A label-free fluorescent sensor based on carbon quantum dots with enhanced sensitive for the determination of myricetin in real samples."Microchem J. 2020 Sep;157:104956 23. [IF=4.539] Ying Liao et al."A biological reactive flame retardant for flame retardant modification of cotton fabric."Colloid Surface A. 2021 Dec;630:127601 24. [IF=3.5] Jiakun Shen et al."Mogroside V exerts anti-inflammatory effects on fine particulate matter-induced inflammation in porcine alveolar macrophages."Toxicol In Vitro. 2022 Apr;80:105326 25. [IF=3.398] Jie Liu et al."Cholesteric Liquid Crystal Photonic Hydrogel Films Immobilized with Urease Used for the Detection of Hg2 ."Chemosensors. 2022 Apr;10(4):140 26. [IF=6.057] Supan Cheng et al."Liquid crystal-based sensitive and selective detection of uric acid and uricase in body fluids."Talanta. 2022 Jul;244:123455 |
urea - Physical and chemical properties
Authoritative Data Verified Data
- urea , also known as urea or carbamide, is an end product of protein metabolism in humans and mammals, it is also a major organic nitride excreted by the animal body. Pure white granular or needle-like, prismatic crystals, iron and other heavy metals are pale red or yellow. Odorless and odorless, soluble in water, ethanol and benzene, insoluble in ether and chloroform. At 20 ℃, 100 of water can dissolve 105 of urea, which is endothermic when dissolved. The aqueous solution showed a neutral reaction. Pure nitrogen content is 46.65%, agricultural urea is 42% ~ 46%, containing a small amount of biuret, generally less than 2%, usually harmless to crop growth; The specific gravity and bulk density of urea are small, the fertilizer weighs 0.65 tons per cubic meter.
- when the temperature of urea is below 20 ℃ and the relative humidity is less than 70%, it will not only absorb moisture, but also make moisture evaporate and reduce its water content; When the temperature exceeds 20 ℃, when the relative humidity is higher than 80%, it begins to absorb moisture, and when it is severe, it is Pasty. When the air is dried, it will agglomerate again, which is second only to ammonium nitrate. Urea aqueous solution at 80 ℃, will occur hydrolysis and decomposition reaction, respectively, the formation of ammonium carbamate and ammonia, carbon dioxide, under acid and alkaline conditions, urea when heated, decomposition accelerated.
- urea is easy to combine with linear carbohydrates to form crystalline additional compounds; With a variety of inorganic compounds, Ca(NO3)2 · 4CO (NH2)2, NH4Cl · CO (NH2)2, CaSO4 · 4CO (NH2)2, MgSO4 · 4CO (NH2)2 · 3H2O, Mg (NO3) · 4CO (NH2)2 · 2H2O and other double salts; Easy to generate Urea phosphate, dicalcium phosphate and water with Monocalcium phosphate, that is, Ca(H2PO4)2 · H2O + CO (NH2)2 & rarr;H3PO4 · CO (NH2)2 + CaHPO4 + H2O; Interaction with nitric acid easily generates urea nitrate, CO (NH2)2 + HNO3 & rarr;CO (NH2)2 · HNO3; it can be combined with formaldehyde to generate urea formaldehyde compounds (uric acid condensation), in which the high proportion of formaldehyde is urea resin, and the low proportion is slow-release (effective) urea.
Last Update:2022-01-01 08:45:26
urea - Nature
Open Data Verified Data
white columnar crystal or crystalline powder. lg this product is soluble in 1ml water, 10mL 95% ethanol, 1mL 95% boiling ethanol, 20ml anhydrous ethanol, 6ml methanol, 2ml glycerol, soluble in concentrated hydrochloric acid, almost insoluble in ether, chloroform. When heated above the melting point, it decomposes into biuret, ammonia and cyanuric acid.
Last Update:2024-01-02 23:10:35
urea - Preparation Method
Open Data Verified Data
ammonia reacts with carbon dioxide to form ammonium carbamate, which is then dehydrated to form urea.
Last Update:2022-01-01 09:26:59
urea - Category
Authoritative Data Verified Data
pharmaceutical excipients, penetration enhancers, cosolvents.
Last Update:2024-01-02 23:10:35
urea - Standard
Authoritative Data Verified Data
This product containing CH4N20 not less than 99.5%.
Last Update:2024-01-02 23:10:35
urea - Trait
Authoritative Data Verified Data
- This product is a colorless prismatic crystal or white crystalline powder; Almost odorless, salty and cool; After long standing, the weak ammonia odor gradually occurs; The aqueous solution shows a neutral reaction.
- This product is soluble in water or ethanol, and insoluble in ether or three gas methane.
melting point
The melting point of this product (General 0612) is 132~135 ℃.
Last Update:2022-01-01 11:59:35
urea - Nitrogen fertilizer
Authoritative Data Verified Data
- urea is an important nitrogen fertilizer with high quality and high efficiency. At the end of the First World War, Germany began to use urea as a fertilizer. Practice has proved that urea has high nitrogen content and no secondary components, and shows good yield increasing effect on all crops. Since the S, it has become the focus of the development of nitrogen fertilizer in all countries. In the 15 years from 1960 to 10.5, the global urea production increased by Times, and from the 70 s began to gradually replace the ammonium nitrate and become the world's most applied nitrogen fertilizer varieties. After urea is applied to the soil, a small part is absorbed by plants in the form of amide, and most of them are ammoniated under the action of urease, converted into ammonia, and then absorbed by plants. The decomposition rate depends on soil quality, temperature and water content, generally in 3~10 days, so the efficiency of urea than other nitrogen fertilizer long, nitrogen loss is less. Urea is an ideal fertilizer for root topdressing, because it does not contain harmful components to crops, is neutral, does not burn stems and leaves, has strong hygroscopicity, is easy to penetrate into leaves with water, and is rapidly absorbed by crops. The concentration of topdressing outside the root is generally 0.5% ~ 2%. In order to improve the effect of urea utilization, in addition to the correct grasp of the nature of urea and application conditions, but also pay attention to the rational application.
- urea is a neutral fertilizer, which does not contain harmful ingredients. The hydrolysis products NH +4 and HCO-3 can be absorbed and utilized by crops. The application of urea in successive years generally has no adverse effect on soil properties. It is suitable for all kinds of crops and soil, and its fertilizer efficiency is similar to that of ammonium sulfate with equal amount of nitrogen. For the lack of active iron and the "old decay" paddy field, which is prone to hydrogen sulfide poisoning, the effect is better than that of ammonium sulfate. Excessive application of urea, or biuret content is too high, easy to cause ammonia and Biuret poisoning of crops; The higher the urease activity of crops, the more sensitive the toxicity of urea and biuret.
- urea can be used as a supplementary feed for anti-young animals. Industrial urea is the raw material for the synthesis of urea-formaldehyde, melamine-formaldehyde resin. Medicine for the manufacture of tetracycline, phenobarbital, caffeine and other drugs. The dye industry uses it to produce reduced Brown BR, Phthalocyanine Blue B, etc.
- the urea is packed in a woven bag lined with a plastic film and a jacket. Should be stored in a dry warehouse, not with the acid substances co-storage and mixed transport.
Last Update:2022-01-01 08:45:26
urea - Use
Open Data Verified Data
examination of antimony and tin, determination of lead, copper, gallium, phosphorus, iodide, nitrate.
Last Update:2022-01-01 09:26:59
urea - Differential diagnosis
Authoritative Data Verified Data
- take 0.5g of this product, place it in a test tube for heating, liquefy and release ammonia gas; Continue to heat until the liquid is turbid, cool, add 10ml of water and 2ml of sodium hydroxide solution for dissolution, add 1 drop of copper sulfate test solution, which shows purplish red.
- take 0.lg of this product, add 1ml of water to dissolve, and then add 1ml of nitric acid to generate white crystalline precipitate.
- The infrared absorption spectrum of this product should be consistent with that of the control (Spectrum set 210).
Last Update:2022-01-01 11:59:35
urea - Application method
Authoritative Data Verified Data
- The application methods of urea include base fertilizer, topdressing, seed fertilizer, and Root external topdressing. The application time of basal and topdressing should be 4~5 days earlier than that of ammonium nitrogen fertilizer, and the application amount should be reduced according to the nitrogen content. Urea should be used as a base fertilizer for paddy field, and should be immediately turned over after spraying 5-7 days before Irrigation. Do not irrigate prematurely after application to reduce the direct loss of urea, keep the shallow water layer, immediately after fertilization, and keep 2~3 days without irrigation. The application method of urea as basal fertilizer and topdressing in dry land is basically similar to that of various ammonium nitrogen fertilizers. Urea is generally not directly used as seed fertilizer, because of the high concentration of urea or ammonia and pH value, it will lead to protein denaturation and hinder seed germination and seedling growth, and even make seeds lose the ability to germinate, it is especially harmful to small seeds; However, if urea is mixed with dry fine soil first and then applied to a certain depth under the seeds, and the seeds are sown after being covered with a thin soil layer; Or the urea is applied at a distance of 2.5 from the seeds, there was no adverse effect on seed germination.
- the rate of absorption and utilization of urea by the leaves of general crops is faster than that of the roots, and the effect of urea as external topdressing is better than that of other nitrogen fertilizers. The reasons are: ① urea is a neutral organic nitrogen, without secondary components, the general concentration of the spray solution on the crop stem and leaf burn is very small. (2) the ionization degree is very small, the molecular volume is small, and it is easy to enter the leaf cell through the cell membrane. (3) molecular urea has a high rate of penetration and diffusion. When it penetrates into cells, it is not easy to separate the plasma wall, even if it occurs, it is easy to recover. (4) it has strong hygroscopicity. The solid urea remaining in the leaf surface due to the evaporation of water in the spray liquid can still be re-absorbed and dissolved, and the absorption and utilization rate is high. The suitable concentration of urea for external-root-topdressing varies with crop species and their growth stages. General rice, wheat and grass grass spraying the optimum concentration of 2.0%, cucumber 1.0% ~ 1.5%, radish, cabbage, spinach and cabbage for 1.0%, watermelon, eggplant, sweet potato, potato, peanut and citrus for 0.4% ~ 0.8%, Mulberry, tea, pear, apple and grape for 0.5%, Persimmon, tomato, strawberry, greenhouse cucumber and eggplant, flowers for 0.2% ~ 0.3%. Usually every 7~10 days spray once, a total of 2~3 times. The dosage of the solution is 750~1125 per hectare each time, which is sprayed to the degree that the leaves are wet. Spraying time in the morning or evening is better. The content of Biuret should not be higher than 0.5% in the urea used as root topdressing so as not to injure the leaves.
Last Update:2022-01-01 08:45:27
urea - Exam
Authoritative Data Verified Data
nitride
take l.Og of this product and check it according to law (General rule 0801). Compared with the control solution made of 7.0ml of standard sodium chloride solution, it should not be more concentrated (0.007%).
sulfate
take 4.0g of this product and check it according to law (General rule 0802). Compared with the control solution made of 0.010% of standard potassium sulfate solution, it should not be more concentrated ().
insolubles in ethanol
Take 5.0g of this product and heat 50ml of ethanol. If there is insoluble matter, filter with a 105°C constant weight vertical melting glass crucible, and wash the filter residue with 20ml of hot ethanol, it was dried at 105°C to constant weight, and the remaining residue should not exceed 2ml.
ignition residue
not more than 0.1% (General rule 0841).
Heavy metals
take this product l. Add 20ml of water to dissolve, add 0.1 mol/L hydrochloric acid solution 5ml, according to the law inspection (General Principles 0821 The first law), containing heavy metals shall not exceed 20 parts per million.
Last Update:2022-01-01 11:59:36
urea - Content determination
Authoritative Data Verified Data
take about 0.15g of this product, weigh it accurately, put it in a Kjeldahl Flask, add 25ml of water, 2ml of 3% copper sulfate solution and 8ml of sulfuric acid, after slowly heating to clear green, continue heating for 30 minutes, cool, add 100ml of water, shake well, slowly add 75ml of 20% sodium hydroxide solution along the wall of the bottle, and form a liquid layer, add 0.2g of zinc particles, connect the Kjeldahl Flask with the condenser tube with a nitrogen balloon, and extend the end of the condenser tube under the liquid level of a ml conical flask containing 50ml of 4% boric acid solution; Gently swing the Kjeldahl Flask, mix the solution evenly, heat the distillation, and stop the distillation once the ammonia is completely distilled; Add several drops of Methyl red indicator solution to the distillate, and titrate with hydrochloric acid titration solution (0.2mol/L), the results of the titration were corrected by a blank test. Each 1 ml of hydrochloric acid titration solution (0.2mol/L) is equivalent to 6.006mg of CH4N2O.
Last Update:2022-01-01 11:59:37
urea - Category
Authoritative Data Verified Data
Last Update:2022-01-01 11:59:37
urea - Storage
Authoritative Data Verified Data
Last Update:2022-01-01 11:59:37
urea - Urea ointment
Authoritative Data Verified Data
This product contains urea (CH4N20) should be 90.0%-110.0% of the label.
trait
This product is yellow consistency uniform ointment.
identification
- take 2-3ml of the remaining solution under the content determination item, add 1 drop of hydrochloric acid, shake well, and add 2-3 drops of 10% G-ton methanol solution of hydrogen alcohol, that is, a precipitate is produced, which should not be dissolved with an equal amount of ethanol.
- take an appropriate amount of this product (about 50mg of urea), add 5ml of anhydrous ethanol, water bath heating to dissolve urea, transfer ice bath cooling, filtration, filtrate as a test solution; in addition, about 50mg of the urea reference substance was added with 5ml of anhydrous ethanol, and the solution was dissolved by shaking, which was used as a reference solution; 1ml of each of the test solution and the reference solution was mixed, and the mixture was used as a system applicable solution. According to the thin layer chromatography (General 0502) test, absorb 5ul of each of the above three solutions, respectively point on the same silica gel G thin layer plate, with anhydrous ethanol and 13.5mol/L ammonia water (99:1) for the development of the agent, expand, take out, dry, spray with anhydrous ethanol solution containing 0.5% dimethylaminobenzaldehyde and 0.5% sulfuric acid, the system applicability solution can only show 1 spot, the position and color of the dominant spot displayed by the test solution should be consistent with the dominant spot of the control solution.
examination
should comply with the relevant requirements under soft AIDS (General rule 0109).
Content determination
take an appropriate amount of this product (about 50mg equivalent to urea), weigh it accurately, put it in a 50ml beaker, add 20ml ethanol, heat it in a water bath to dissolve the urea, after cooling in the ice bath for 30 minutes, filter the filtrate, place the filtrate in a 100ml measuring flask, rinse the container with ethanol, filter, and then rinse the filter with ethanol, dilute with ethanol to the scale, shake, as a test solution; Take the appropriate amount of urea reference, precision weighing, dissolving with ethanol and quantitatively diluting to make a solution containing about 0.5mg per 1 ml, as a control solution. 3ml of test solution and 3ml of reference solution were respectively placed in a 25ml measuring flask, and then p-DIW aminobenzaldehyde solution (2g of p-dimethylaminobenzaldehyde, add 96ml ethanol and 4ml hydrochloric acid to dissolve, then obtain) 10ml, dilute with ethanol to the scale, shake, place in the dark for 15 minutes, filter if necessary, immediately according to UV-visible spectrophotometry (General rule 0401), the absorbance was measured at a wavelength of NM, and the calculation was obtained.
category
skin external use.
specification
10%
storage
sealed, stored in the cool dark.
Last Update:2022-01-01 11:59:38
urea - Quality Indicators
Authoritative Data Verified Data
- Content/%≤ 0.0005 0.001
- alkalinity (based on NH3 content)/%≤ 0.015 0.030
- water insoluble content/%≤ 0.01 O.04
- Water/% is less than or equal to 0.50 1.00 Industrial urea quality indicators:(GB 2440 a 2001)
- Index Name: first-class product
- Appearance: white particles or crystals
- Mass fraction of total nitrogen (N) (on dry basis)/%≥ 46.3 46.3
- Biuret content/%≤ -0.50 1.00
- iron (Fe)
- particle size (& phi;0.8~2.5)/%≥ 90 90
Last Update:2022-01-01 08:45:30
urea - Urea Cream
Authoritative Data Verified Data
This product contains urea (CH4N20) should be 90.0% to 110.0% of the label.
trait
This product is white cream.
identification
- take an appropriate amount of this product (about 0.5g of urea), put it in a separatory funnel, add 50ml of chloroform, shake to disperse, add 4g of sodium chloride and ml of water, and extract with shaking, once the layers were separated, the upper aqueous solution was collected in a 200ml beaker, the water was distilled off, and the residue was used up.
- take a small amount of the above residue, place it in a test tube, and slowly heat it (be careful not to carbonize), that is, ammonia odor occurs, which can make the wet red litmus test paper turn blue; Continue to heat for several minutes, cool, add 10ml of water to dissolve, add 1 ml of sodium hydroxide test solution, mix well, add 1 drop of copper sulfate test solution, shake well, the solution is blue-purple.
- a saturated solution was prepared by taking an appropriate amount of the above-mentioned residue and adding an appropriate amount of water. 1ml of the supernatant was taken, and 1ml of nitric acid was added thereto, followed by shaking.
examination
should comply with the relevant provisions under Cream (General rule 0109).
Content determination
take an appropriate amount of this product, accurately weigh (about 50mg of urea), put it in a 50ml beaker, add 20ml of ethanol, heat it in a water bath to dissolve the urea, and cool it in an ice bath for 30 minutes, filter, the filtrate is placed in a 100ml measuring flask, the container and filter are washed with ethanol, the washing liquid is incorporated into the measuring flask, put to room temperature, dilute to the scale with ethanol, shake, filter, the filtrate was used as the test solution; An appropriate amount of urea reference substance was additionally taken, precisely weighed, dissolved and quantitatively diluted with ethanol to make a solution containing about 0.5mg per 1 ml, which was used as the reference solution. The sample solution and the reference solution were respectively placed in the 25mi measuring flask, and the p-dimethylaminobenzaldehyde solution was added (2g of p-dimethylaminobenzaldehyde, 96ml of ethanol and 4ml of hydrochloric acid were added to dissolve the solution). 10ml, diluted with ethanol to the scale, shake, dark place 15 minutes, if necessary, immediately according to UV-visible spectrophotometry (General rule 0401), determination of absorbance at the wavelength of 420mn, it is obtained by calculation.
category
Same as urea.
specification
(l ) lOg:0.2g (2 )10g:1g ( 3 ) l0g:2g
storage
sealed and stored in a cool place.
Last Update:2022-01-01 11:59:39
urea - Nature
Open Data Unverified Data
urea alias carbamide, carbamide, urea. Is composed of carbon, nitrogen, oxygen and hydrogen organic compounds, also known as urea. The chemical formula is CON2H4, (NH2)2CO or CN2H4O, and the international non-patent drug name is Carbamide. The appearance is white crystals or powder. It is a product of animal protein metabolism and is commonly used as a nitrogen fertilizer for plants. Urea is synthesized in the liver and is a nitrogenous metabolite excreted by mammals. This metabolic process is called the urea cycle. Urea was the first organic compound obtained by artificial synthesis of inorganic substances.
Last Update:2024-04-09 19:43:38
urea - Ruminant feed additive
Open Data Unverified Data
The United States began to add urea to the feed of ruminants in the early 40s of the 20th century. After 50s, urea has been widely used as a non-protein nitrogen source for ruminants worldwide. In the late 80 s, the total amount of urea used in the United States was 1 million tons, which is equivalent to 5% of the total output of urea in the United States. In the early 90 s of China, the total output of urea was about 6 million tons, and the amount of feed was about 2%~ 3%.
Urea is mainly used for feeding ruminant livestock such as cattle and sheep. So far, it is still rare to see the scientific basis for the use of monogastric animals. In order to ensure the reasonable and effective use and prevent the increase of pH value in the rumen of livestock and the occurrence of ammonia poisoning, the use of urea feed should pay attention to the following points:
- mix evenly, limit feed intake, intake of urea containing feed can not immediately drink water.
- The diet should contain a certain amount of easily fermented carbohydrates, of which molasses is the best, followed by starch dextrin, and fiber feed is poor.
- the supply of appropriate and balanced quantities of minerals, with particular attention to the supply of cobalt, zinc, sulfur to meet the needs of rumen microbial reproduction.
- diet should not be mixed with urease containing feed, such as raw beans, raw soybean meal, etc.
- for the initial feeding of urea feed or only coarse feed, Hay, livestock and young livestock to adopt a gradual increase in the amount of urea to gradually adapt to the feeding mode.
- urea can be used in high-energy low-protein or low-energy low-protein diets, but the utilization of urea is poor in low-energy high-protein or high-energy high-protein diets.
the appropriate amount of urea should be determined based on the fermentation potential of urea.
Urea poisoning occurs very quickly, the course is short, usually in ten minutes to a few hours after eating. Clinical symptoms are: restlessness, trembling, a large number of salivation, shortness of breath, muscle movement is not coordinated, swelling, convulsions and so on. General irrigation with 6 liters containing 5% of acetic acid solution, the acid and ammonia can be combined to prevent excessive ammonia into the blood.
Last Update:2024-04-09 19:43:38
urea - Identification Test
Open Data Unverified Data
soluble in water, soluble in ethanol (OT-42).
Nitric acid precipitation test sample 0.1g dissolved in water, plus 1ml of concentrated nitric acid. There should be a white crystalline precipitate.
Color reaction 1g of sample was taken from the test tube, heated for liquefaction, and allowed to cool until the solution became turbid and dissolved in a mixture of l0ml water and lmL2mol/L NaOH, and copper sulfate solution (TS-78) was added. 0.05. Should appear red-purple.
The melting range was 132-135 ℃.
Last Update:2024-04-09 19:43:38
urea - Toxicity
Open Data Unverified Data
GRAS(FDA & sect;184.1923,2000).
Ld5014300 mg/kg (rat, oral).
Can be used, not more than 3% of the gum is not toxic (FAO/WHO,2001).
Last Update:2024-04-11 22:27:45