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1.
化妆品试样经水提取,采用离子排斥色谱法测定化妆品中硼酸的含量。以IonPac ICEBorate(250mm×9mm,7.5μm)排斥色谱柱为离子交换柱,以3mmol·L~(-1)甲烷磺酸(MSA)-60mmol·L~(-1)甘露醇混合溶液为淋洗液,采用非抑制电导器检测。硼酸在0.12~20.0mg·L~(-1)范围内呈线性范围,方法的检出限(3s)为0.85mg·kg~(-1)。方法用于化妆品试样中硼酸的测定,平均加标回收率在93.2%~103.5%之间,相对标准偏差(n=6)在2.4%~5.9%之间。  相似文献   

2.
建立了磷酸蒸馏-离子色谱法测定药物中氰根总量的方法。样品在加入磷酸的环境下,加热蒸馏,将氰根转化成氰化氢的形式被蒸馏出来,经过冷凝管后被氢氧化钠溶液吸收。吸收液用离子色谱-安培检测器测定氰根含量。离子色谱条件:IonPac AS11-HC色谱柱(250mm×4mm)和IonPac AG11-HC保护柱(50mm×4mm),流量1.0mL·min~(-1),4mmol·L~(-1)氢氧化钠淋洗液。氰根的质量浓度在0.02~1.0mg·L~(-1)内与其峰面积之间呈线性关系,相关系数为0.999 7,检出限(3S/N)为0.004 mg·L~(-1),样品的加标回收率为100%~102%,相对标准偏差(n=6)为1.0%~2.1%。该方法灵敏度好、精密度和重复性高,有效避免了药物基体的干扰,为难以消除的基体药物中氰根的测定提供新方法和新思路。  相似文献   

3.
采用离子色谱法测定工作场所空气中六价铬的含量。采用碱性微孔滤膜采集工作场所空气样品,经4.0mmol·L~(-1)碳酸钠溶液超声洗脱后,选用Metrosep A Supp 4-250型阴离子色谱柱(250mm×4.0mm)进行色谱分离。以4.0mmol·L~(-1)碳酸钠-1.0mmol·L~(-1)碳酸氢钠混合液为流动相,抑制型电导检测器测定。六价铬的质量浓度在0.01~10.0mg·L~(-1)内与其峰面积呈线性关系,方法的检出限(3S/N)为4×10-3 mg·L~(-1)。加标回收率在95.2%~97.6%之间,测定值的相对标准偏差(n=6)在2.2%~3.8%之间。  相似文献   

4.
采用离子色谱法测定瓶装水中7种阴离子的含量。水样经Ion Pac AG14保护柱及IonPac AS14分离柱分离,以3.5mmol·L~(-1)碳酸钠-1.0mmol·L~(-1)碳酸氢钠溶液为淋洗液,采用抑制电导器检测。F~-和PO_4~(3-)分别在0.05~1.20mg·L~(-1)和0.80~3.00mg·L~(-1)范围内,Cl~-、NO_2~-、Br~-、NO_3~-和SO_4~(2-)均在0.20~4.80mg·L~(-1)范围内呈线性关系,检出限(3S/N)在0.025~0.126mg·L~(-1)之间。方法用于瓶装水中7种阴离子的测定,加标回收率在92.8%~102.0%之间,相对标准偏差(n=7)均小于4.0%。  相似文献   

5.
本文建立了离子色谱等度测定富锂锰基正极材料中硫酸根离子的方法。样品经浓盐酸溶解后,经氢柱过滤后进样,色谱柱采用SH-AP-1分离柱,流动相15 mmol·L~(-1)氢氧化钾溶液,流速0.6 mL·min~(-1)。结果表明:在0.02~10 mg·L~(-1)范围内,硫酸根离子浓度与峰面积呈良好线性关系(R~2=0.9999),检出限为10 mg·kg~(-1),平均加标回收率为92.39~107.53%,相对标准偏差为0.84~4.11%(n=7)。该方法准确、简便、灵敏、重复性好,且成本低,可用于富锂锰基中硫酸根离子的实际检测。  相似文献   

6.
采用自动快速燃烧炉-离子色谱法测定煤炭中氯的含量。优化的试验条件如下:(1)燃烧管进口温度为950℃,出口温度为1 050℃;(2)称样量为10 mg;(3)以4.5 mmol·L~(-1)碳酸钠-1.4mmol·L~(-1)碳酸氢钠混合液为吸收液。以阴离子色谱柱为分离柱,4.5 mmol·L~(-1)碳酸钠-1.4mmol·L~(-1)碳酸氢钠混合液为淋洗液,抑制型电导检测器测定。以PO_4~(3-)作为内标物,氯的线性范围为0.5~20μg·L~(-1),检出限(3S/N)为0.086mg·L~(-1)。方法应用于煤炭标准物质和实际样品的分析,测定值与认定值相符,测定值与国家标准方法的测定结果相符,测定值的相对标准偏差(n=6)为2.4%~7.5%。  相似文献   

7.
分别采用KOH和Na_2CO_3/NaHCO_3淋洗液体系,建立了离子色谱直接测定聚合级乙二醇中痕量氯离子含量的两种方法。采用抽真空手动进样方式,分别以IonPac AS19(4 mm×250mm)为分析柱,IonPac AG19(4mm×50mm)为保护柱,5mmol·L~(-1) KOH溶液为淋洗液;以IonPac AS23(4mm×250mm)为分析柱,IonPac AG23(4mm×50mm)为保护柱,4.5mmol·L~(-1)Na_2CO_3-0.8mmol·L~(-1) NaHCO_3混合溶液为淋洗液进行分离,以电导检测器检测。两种方法中,氯离子的质量比在一定范围内与峰面积呈线性关系,检出限(10S/N)分别为0.002,0.006mg·kg~(-1),加标回收率分别为94.7%~100%,92.3%~99.8%,测定值的相对标准偏差(n=3)小于5.0%。两种方法测定聚合级乙二醇中痕量氯离子的结果具有一致性。  相似文献   

8.
建立了高效液相色谱(HPLC)外标定量分析咪唑生产工艺中反应液中咪唑及杂质2-甲基咪唑和4-甲基咪唑含量的方法。在色谱分析中,选用Supersil-ODS-B色谱柱为固定相;选用体积比为40∶60的乙腈-离子对试剂(溶液pH为3.5,内含16 mmol·L~(-1)十二烷基硫酸钠和17mmol·L~(-1)磷酸二氢钾)溶液为流动相进行等度洗脱;采用二极管阵列检测器进行检测,检测波长为210nm。结果显示:咪唑、2-甲基咪唑及4-甲基咪唑标准曲线的线性范围均为10~100mg·L~(-1),检出限(3S/N)分别为0.02,0.02,0.03mg·L~(-1)。咪唑在20mg·L~(-1)和100mg·L~(-1)添加水平下的平均加标回收率分别为100%,99.2%,相对标准偏差(n=8)为0.27%。用本方法对同一批反应液不同反应阶段的9个样品中咪唑进行了测定,测定值为10.11%~10.71%;杂质2-甲基咪唑有检出,但低于测定下限;杂质4-甲基咪唑未检出。与气相色谱法进行了比对,两者测定结果基本一致。试验结果表明,该方法准确度好、灵敏度高、重现性好,能够准确测定咪唑生产工艺中反应液中咪唑、2-甲基咪唑及4-甲基咪唑的含量。  相似文献   

9.
以手性色谱柱为分离柱,串联蒸发光散射检测器(ESLD),采用反相高效液相色谱法测定普瑞巴林原料药中普瑞巴林R-异构体的含量。色谱条件如下:CHIRALPAK ZWIX(+)(4.0mm×150mm,3μm)为手性分离柱,柱温为25℃;甲醇-乙腈-水-甲酸-二乙胺(450+450+100+2.0+2.5)为流动相,流量为0.5 mL·min~(-1);ESLD漂移管温度为70℃,载气流量为2.0L·min~(-1)。普瑞巴林R-对映异构体的线性范围为0.80~4.5mg·L~(-1),检出限为0.30mg·L~(-1),测定下限为0.80mg·L~(-1)。加标回收率为93.8%~94.5%,测定值的相对标准偏差(n=6)小于2.5%。  相似文献   

10.
称取羧甲基淀粉钠样品(0.50g左右),加超纯水定容至100mL,摇匀,静置。取上清液过反相固相萃取柱,弃去先流出液3mL,收集其后流出液2mL(供测定Cl-离子用的试液需再次稀释10倍),供色谱分析。选用SH-AC-4型阴离子交换柱(250mm×4.6mm)进行色谱分离,以2.4mmol·L~(-1)碳酸钠-6.0mmol·L~(-1)碳酸氢钠溶液为流动相,用抑制型电导检测器测定。所测5种阴离子均在一定的质量浓度范围内与其峰面积呈线性关系,方法的检出限(3S/N)为0.027,0.020,0.007 0,0.16,0.022 mg·L~(-1)。方法用于羧甲基淀粉钠样品的分析,加标回收率在88.3%~108%之间,测定值的相对标准偏差(n=5)在0.68%~11%之间。  相似文献   

11.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

12.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

13.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

14.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

15.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

16.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

17.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

18.
An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.  相似文献   

19.
20.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

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