USP32
Leucine
C6H13NO2 131.17
l-Leucine.
l-Leucine [61-90-5].
? Leucine contains not less than 98.5 percent and not more than 101.5 percent of C6H13NO2, as l-leucine, calculated on the dried basis.
Packaging and storage— Preserve in well-closed containers.
USP Reference standards 11—
USP L-Leucine RS.
USP L-Valine RS.
Identification, Infrared Absorption 197K.
Specific rotation 781S: between +14.9 and +17.3.
Test solution: 40 mg per mL, in 6 N hydrochloric acid.
pH 791: between 5.5 and 7.0, in a solution (1 in 100).
Loss on drying 731— Dry it at 105 for 3 hours: it loses not more than 0.2% of its weight.
Residue on ignition 281: not more than 0.4%.
Chloride 221— A 0.73-g portion shows no more chloride than corresponds to 0.50 mL of 0.020 N hydrochloric acid (0.05%).
Sulfate 221— A 0.33-g portion shows no more sulfate than corresponds to 0.10 mL of 0.020 N sulfuric acid (0.03%).
Iron 241: 0.003%.
Heavy metals, Method II 231: 0.0015%.
Chromatographic purity—
Adsorbent: 0.25-mm layer of chromatographic silica gel mixture.
Test solution— Dissolve an accurately weighed quantity of Leucine in 0.1 N hydrochloric acid to obtain a solution having a concentration of 10 mg per mL. Apply 5 μL.
Standard solution— Dissolve an accurately weighed quantity of USP
L-Leucine RS in 0.1 N hydrochloric acid to obtain a solution having a known concentration of about 0.05 mg per mL. Apply 5 μL. [note—This solution has a concentration equivalent to about 0.5% of that of the Test solution.]
System suitability solution— Prepare a solution in 0.1 N hydrochloric acid containing 0.4 mg each of USP L-Leucine RS and USP L-Valine RS per mL. Apply 5 μL.
Spray reagent— Dissolve 0.2 g of ninhydrin in 100 mL of a mixture of butyl alcohol and 2 N acetic acid (95:5).
Developing solvent system— Prepare a mixture of butyl alcohol, glacial acetic acid, and water (60:20:20).
Procedure— Proceed as directed for Thin-Layer Chromatography under Chromatography 621 . After air-drying the plate, spray with Spray reagent, and heat between 100 and 105 for about 15 minutes. Examine the plate under white light. The chromatogram obtained from the System suitability solution exhibits two clearly separated spots. Any secondary spot in the chromatogram obtained from the Test solution is not larger or more intense than the principal spot in the chromatogram obtained from the Standard solution: not more than 0.5% of any individual impurity is found; and not more than 2.0% of total impurities is found.
Assay— Transfer about 130 mg of Leucine, accurately weighed, to a 125-mL flask, dissolve in a mixture of 3 mL of formic acid and 50 mL of glacial acetic acid, and titrate with 0.1 N perchloric acid VS, determining the endpoint potentiometrically. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 13.12 mg of
C6H13NO2.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Curtis Phinney
1-301-816-8540 (DSN05) Dietary Supplements - Non-Botanicals
Reference Standards Lili Wang, Technical Services Scientist
1-301-816-8129
RSTech@https://www.360docs.net/doc/8117600387.html,
USP32–NF27 Page 2758
Chromatographic Column—
LEUCINE
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.
亮氨酸
c6h13no2 131.17
亮氨酸。
61-90-5亮氨酸[ ]。
?亮氨酸含量不少于百分之98.5，不超过百分之101.5 c6h13no2亮氨酸，作为计算的基础。
包装与贮存：保存在封闭的容器。
药典参考标准11—
美国药典亮氨酸。
美国药典缬氨酸。
识别，红外吸收197k。
比旋光度781s：+ 14.9和+ 17.3之间。
测试解决方案：40毫克每毫升，在6盐酸。
791：5.5和7，在一个解决方案（1，100）。
干燥失重731 -干在105 3个小时就不超过0.2%的重量。
灼烧残渣281：不超过0.4%。
氯化221 - 0.73-g部分显示没有氯比相当于0.50毫升的盐酸（0.05%）0.020。
硫酸221 - 0.33-g部分没有显示出更比硫酸相当于0.10毫升0.020的硫酸
（0.03%）。
铁241 : 0.003%。
重金属，方法231：0.0015%。
色谱纯度—
吸附剂：0.25毫米层色谱硅胶混合物。
测试解决方案-解散一个准确称量的亮氨酸0.1盐酸获得的溶液浓度为10毫克每毫升5μ申请L
标准溶液溶解一个准确称量药典亮氨酸在0.1盐酸获得解决方案有一个已知的
浓度约为0.05毫克每毫升5μL [注意事项：本方案具有浓度相当于约0.5%的测试解决方案。]
系统适用性的解决方案-准备在0.1盐酸溶液含有0.4毫克每药典和美国药典缬氨酸亮氨酸遥感应用μ每毫升5 L。
喷雾试剂溶解0.2克的茚三酮在100毫升的混合物丁醇和2醋酸（18）。
显影溶剂系统-准备混合丁醇，乙酸，水（60 : 20 :）。
程序：按621下的薄层色谱法。风干后的板，喷雾喷雾试剂，与热之间的100和105约15分钟。检查板下白光。色谱系统适用性解决方案展品从2明确分开的点。任何中学获得了色谱点的测试解决方案是没有更大或更激烈的比主获得了色谱点从标准溶液：不超过0.5%的任何单个杂质被发现；和不超过2%的杂质被发现。
检测转移约130毫克的亮氨酸，准确称量，以125-ml瓶，溶解在混合3毫升甲酸50毫升冰醋酸，和0.1的高氯酸滴定终点判断potentiometrically队。进行空白检测，并作必要的修正。每毫升0.1的高氯酸相当于13.12毫克的c6h13no2。
辅助信息-请检查您的问题在常见问题联系之前，美国药典。
话题/问题联系专家委员会
柯蒂斯菲尼专著
1-301-816-8540（dsn05）膳食补充剂- non-botanicals
莉莉王的参考标准，技术服务的科学家
1-301-816-8129
rstech@https://www.360docs.net/doc/8117600387.html,
usp32–nf27 2758页
色谱柱—
亮氨酸
色谱柱的文本是不从，而不是一部分，美国药典32和因子27。
Isoleucine
C6H13NO2 131.17
l-Isoleucine.
l-Isoleucine [73-32-5].
? Isoleucine contains not less than 98.5 percent and not more than 101.5 percent of C6H13NO2, as l-isoleucine, calculated on the dried basis. Packaging and storage— Preserve in well-closed containers.
USP Reference standards 11 — USP L-Isoleucine RS. USP L-Valine RS. Identification, Infrared Absorption 197K .
Specific rotation 781S : between +38.9 and +41.8 .
Test solution: 40 mg per mL, in 6 N hydrochloric acid.
pH 791 : between 5.5 and 7.0, in a solution (1 in 100).
Loss on drying 731 — Dry it at 105 for 3 hours: it loses not more than 0.3% of its weight.
Residue on ignition 281 : not more than 0.3%.
Chloride 221 — A 0.73-g portion shows no more chloride than corresponds to 0.50 mL of 0.020 N hydrochloric acid (0.05%).
Sulfate 221 — A 0.33-g portion shows no more sulfate than corresponds to 0.10 mL of 0.020 N sulfuric acid (0.03%).
Iron 241 : 0.003%.
Heavy metals, Method I 231 : 0.0015%.
Chromatographic purity—
Adsorbent: 0.25-mm layer of chromatographic silica gel mixture.
Test solution— Dissolve an accurately weighed quantity of Isoleucine in 0.1 N hydrochloric acid to obtain a solution having a concentration of 10 mg per mL. Apply 5 μL.
Standard solution— Dissolve an accurately weighed quantity of USP
l-Isoleucine RS in 0.1 N hydrochloric acid to obtain a solution having a known concentration of about 0.05 mg per mL. Apply 5 μL. [note—This solution has a concentration equivalent to about 0.5% of that of the Test solution.]
System suitability solution— Prepare a solution in 0.1 N hydrochloric acid containing 0.4 mg each of USP l-Isoleucine RS and USP l-Valine RS per mL. Apply 5 μL.
Spray reagent— Dissolve 0.2 g of ninhydrin in 100 mL of a mixture of butyl alcohol and 2 N acetic acid (95:5).
Developing solvent system— Prepare a mixture of butyl alcohol, glacial acetic acid, and water (60:20:20).
Procedure— Proceed as directed for Thin-Layer Chromatography under Chromatography 621 . After air-drying the plate, spray with Spray reagent, and heat between 100 and 105 for about 15 minutes. Examine the plate under white light. The chromatogram obtained from the System suitability solution exhibits two clearly separated spots. Any secondary spot in the chromatogram obtained from the Test solution is not larger or more intense than the principal spot in the chromatogram obtained from the Standard
solution: not more than 0.5% of any individual impurity is found; and not more than 2.0% of total impurities is found.
Assay— Transfer about 130 mg of Isoleucine, accurately weighed, to a
125-mL flask, dissolve in a mixture of 3 mL of formic acid and 50 mL of glacial acetic acid, and titrate with 0.1 N perchloric acid VS, determining the endpoint potentiometrically. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 13.12 mg of
C6H13NO2.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact E xpert Committee
Monograph Curtis Phinney
1-301-816-8540 (DSN05) Dietary Supplements - Non-Botanicals Reference Standards Lili Wang, Technical Services Scientist
1-301-816-8129
RSTech@https://www.360docs.net/doc/8117600387.html,
USP32–NF27 Page 2698
Chromatographic Column—
ISOLEUCINE
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.
异亮氨酸
c6h13no2 131.17
异亮氨酸。
73-32-5异亮氨酸[ ]。
?异亮氨酸含量不少于百分之98.5，不超过百分之101.5 c6h13no2异亮氨酸，作为计算的基础，干。
包装与贮存：保存在封闭的容器。
药典参考标准11 -美国药典药典缬氨酸异亮氨酸卢比卢比。
识别，红外吸收197k。
比旋光度781s：+ 38.9和+ 41.8之间。
测试解决方案：40毫克每毫升，在6盐酸。
791：5.5和7，在一个解决方案（1，100）。
干燥失重731 -干在105 3个小时就不超过0.3%的重量。
灼烧残渣281：不超过0.3%。
氯化221 - 0.73-g部分显示没有氯比相当于0.50毫升的盐酸（0.05%）0.020。
硫酸221 - 0.33-g部分没有显示出更比硫酸相当于0.10毫升0.020的硫酸（0.03%）。
铁241 : 0.003%。
重金属，方法231：0.0015%。
色谱纯度—
吸附剂：0.25毫米层色谱硅胶混合物。
测试解决方案-解散一个准确称量的异亮氨酸0.1盐酸获得溶液浓度为10毫克每毫升5μ申请L
标准溶液溶解一个准确称量药典异亮氨酸在0.1的盐酸获得解决方案有一个已知的浓度约为0.05毫克每毫升5μL [注意事项：本方案具有浓度相当于约0.5%的测试解决方案。]
系统适用性的解决方案-准备在0.1盐酸溶液含有0.4毫克每药典和美国药典异亮氨酸缬氨酸遥感应用μ每毫升5 L。
喷雾试剂溶解0.2克的茚三酮在100毫升的混合物丁醇和2醋酸（18）。
显影溶剂系统-准备混合丁醇，乙酸，水（60 : 20 :）。
程序：按621下的薄层色谱法。风干后的板，喷雾喷雾试剂，与热之间的100和105约15分钟。检查板下白光。色谱系统适用性解决方案展品从2明确分开的点。任何中学获得了色谱点的测试解决方案是没有更大或更激烈的比主获得了色谱点从标准溶液：不超过0.5%的任何单个杂质被发现；和不超过2%的杂质被发现。
检测转移约130毫克的异亮氨酸，准确称量，以125-ml瓶，溶解在混合3毫升甲酸50毫升冰醋酸，和0.1的高氯酸滴定终点判断potentiometrically队。进行空白检测，并作必要的修正。每毫升0.1的高氯酸相当于13.12毫克的c6h13no2。
辅助信息-请检查您的问题在常见问题联系之前，美国药典。
话题/问题联系专家委员会
柯蒂斯菲尼专著
1-301-816-8540（dsn05）膳食补充剂- non-botanicals
莉莉王的参考标准，技术服务的科学家
1-301-816-8129
rstech@https://www.360docs.net/doc/8117600387.html,
usp32–nf27 2698页
色谱柱—
异亮氨酸
色谱柱的文本是不从，而不是一部分，美国药典32和因子27。