吡罗昔康凝胶有效成分的高效液相色谱研究

本文提出了采用内标法 ,将 HPLC用于吡罗昔康凝胶有效成分测定的新方法。讨论了流动相及内标的选择 ,进样量和空白基质的影响等。在优化的实验条件下 ,吡罗昔康浓度在 0 .0 2～ 0 .2 mg/m L范围内 ,其浓度与吡罗昔康和内标的峰面积之比呈线性关系。应用于实际样品分析 ,其结果与紫外分光光度法一致 ,平均回收率为 99.6% ,相对标准偏差为 1 .0 %。方法简单 ,准确度高 ,专属性强 ,可用于吡罗昔康凝胶样品的稳定性考察和质量控制     

核磁共振波谱法测定片剂中盐酸巴马汀含量

以氘代甲醇为溶剂,马来酸为内标,通过比较马来酸内标峰与盐酸巴马汀定量峰的峰面积,采用核磁共振法测定了黄藤素片中盐酸巴马汀的含量。结果显示,该方法的线性范围为1. 00～10. 00 g/L,相关系数(r)为0. 999 3,定量下限为25. 0 mg/L,检出限为8. 5 mg/L,回收率为98. 5%～104%。测定结果与高效液相色谱法基本一致。该方法操作简便、测定结果准确,且与结构鉴定同步完成,适用于黄藤素片的质量控制。     

在线凝胶渗透色谱-气相色谱串联质谱法测定动物源性食品中氯霉素

建立了在线凝胶渗透色谱-气相色谱串联质谱(GPC-GC-MS/MS)测定动物源性食品中氯霉素的方法。样品经提取、净化、衍生化和定容后,用大体积进样装置取100μL进样,过凝胶渗透色谱柱后由切换阀排出残留的脂肪和色素等大分子物质,剩余的组分经色谱柱分离,质谱选择EI源多反应监测模式(MRM)检测,内标法定量。氯霉素浓度在0. 25～10 ng/mL范围内和其衍生物与内标衍生物的峰面积比呈线性关系,相关系数r=0. 9976,检出限为0. 05μg/kg,在低、中和高3个添加水平下,回收率在84. 0%～96. 1%之间; RSDs在2. 1%～8. 2%之间。该方法检出限低,精密度和准确度高,适用于动物源性食品中氯霉素的测定。     

基体辅助激光解吸电离飞行时间质谱用于人参皂甙Rg3的定量分析

考察了基体辅助激光解吸电离时间飞行质谱用于人参皂甙Rg3 定量分析时内标的选择。加入棉子糖作为内标时 ,Rg3 的定量标准曲线的回归系数R2 =0 .938,平均相对误差为 2 8 6 % ;加入性质相近的芦丁后 ,Rg3 的定量标准曲线的回归系数R2 =0 993,平均相对误差为 7 5 %。分辨率的提高以及采用Rg3 和内标物的质谱峰的相对面积来代表Rg3 的浓度可以使定量的重现性明显改善     

金属材料分析方法的选择和施行第二讲纯铝的分析及其方法的选择(续)

2 .5　硅的测定方法的选择从高纯铝的技术规范可见在 5个牌号中仅ＬＧ5中硅的含量要求低于 0 .0 0 0 2 5 % ,而从ＬＧ4到ＬＧ1,硅量应分别控制在 0 .0 15 % ,0 .0 4 % ,0 .0 6%和 0 .0 8%以下。因此选择方法时可分别考虑 ,即选择一种测定范围为 0 .0 0 0 10 %～ 0 .0 0 0 5 0 %的方法 ,供分析ＬＧ5试样用。另选一种测定范围在 0 0 10 %～ 0 .10 %之间的方法 ,用于分析其余 4个牌号的样品。在目前应用于测定纯铝中硅的方法都是以形成硅钼杂多酸的反应为基础的光度分析法 ,只是在许多操作细节上有区别 ,各方法的提要如下。(1)方法 1　ＧＢ/Ｔ…     

海产品中残留三唑磷的GC/MS分析

建立了海产品中残留三唑磷农药的毛细管气相色谱-质谱联用检测法.向冷冻干燥后的样品中加入邻苯二甲酸二戊酯作为定量内标,用乙酸乙酯正己烷(11 V/V)提取,浓缩定容后用EI源在SIM检测模式下进行检测.结果表明,三唑磷与内标在SBP-50柱上得到良好的分离,色谱出峰尖锐,没有杂峰干扰.方法在2.5～50 ng/mL浓度范围内线性关系良好,线性方程为Y=8.261×10-4x,相关系数为0.9998.方法的最低检测限低于0.3 ng/mL.当向1.00g样品中添加三唑磷10～500 ng/mL时,平均回收率分别达到95.6%～100.1%,标准相对偏差为2.37%～3.55%.对采自浙江沿海几种海产品测定,三唑磷含量在0～1.34 ng/g范围内.     

异硫氰酸苯酯柱前衍生化反相高效液相法同时测定18种氨基酸

 建立了一种利用反相高效液相同时测定 18种氨基酸的方法。以正亮氨酸为内标物 ,异硫氰酸苯酯为柱前衍生剂 ,用C18柱在柱温 38℃下采用二元梯度洗脱 ,于 2 5 4nm波长处检测。氨基酸质量浓度在 3 5mg/L～ 5 5 6mg/L时 ,其峰面积与内标物峰面积的比值和氨基酸的质量浓度的线性相关系数 ,除胱氨酸 (0 96 2 )外均大于 0 99;18种氨基酸的加标回收率在 96 0 %～ 10 2 .4 %。信噪比为 2时 ,亮氨酸最低检测限为 0 5mg/L。应用该方法对小牛血去蛋白注射液中的游离氨基酸含量进行了测定 ,取得了满意的结果。     

气相法分析血浆中的全氟辛酸

 采用气相 电子捕获法测定了人血浆中全氟辛酸的含量。将血浆中的全氟辛酸酯化后进行分析 ,以全氟癸酸为内标。柱为HP 1熔融石英毛细管柱 (30m× 0 2 5mmi.d .× 0 2 5 μm)。方法的线性范围为 2 0 0 0μg/L～ 4 0 0× 10 3 μg/L ,线性相关系数r =0 994 6。平均回收率为 99 2 % ,相对标准偏差 (RSD)为 0 95 % ,血浆中全氟辛酸的检出限为 6 0 μg/L。方法准确、可靠 ,分析结果令人满意。     

高效液相色谱法分析生物样品中的敌鼠

 研究用阴离子交换、氰基及硅胶柱固相萃取技术分离提取血、尿、肝及肾中的敌鼠。以香豆素作内标 ,用高效液相色谱 二极管阵列检测器方法进行分离鉴定。色谱条件 :分析柱为HypersilBDSC18(5 μm ,15 0mm× 4 6mmi.d .) ,保护柱为PhenomenexODS(4mm× 3 0mmi.d .) ;流动相 :A为 0 5 %离子对A水溶液 ,B为 0 5 %离子对A甲醇溶液 ,以梯度淋洗程序分离 ;检测波长为 2 86nm。当敌鼠的质量浓度在 1mg/L～ 10 0mg/L范围时 ,其浓度同其峰面积与内标物的峰面积之比有良好的线性关系 (r=0 9999) ,最小检出限量为 5ng(按S/N =3计 )。     

电感耦合等离子体原子发射光谱法测定化妆品中硼酸及硼酸盐含量

化妆品样品采用微波消解法处理,用电感耦合等离子体原子发射光谱法测定样品溶液中的硼酸和硼酸盐含量。选择钇元素作为内标元素,选择波长249.678nm谱线作为硼的分析线。硼的质量浓度在1.0mg.L-1以内与其发射强度呈线性关系,方法的检出限(3s)为0.002mg.L-1。方法用于分析了几类化妆品样品,回收率在95.2%～100%之间,测定值的相对标准偏差(n=10)在2.4%～3.8%之间。     

A quick,easy, cheap,effective, rugged,and safe method for the simultaneous detection of four triazolone herbicides in cereals combined with ultrahigh performance liquid chromatography with tandem mass spectrometry

This paper describes a novel, rapid, and sensitive analytical method for monitoring four triazolone herbicides in cereals (wheat, rice, corn, and soybean), using a quick, easy, cheap, effective, rugged, and safe sample extraction procedure followed by ultrahigh performance liquid chromatography coupled with tandem mass spectrometry. The four triazolone herbicides (amicarbazone, carfentrazone‐ethyl, sulfentrazone, and thiencarbazone‐methyl) were extracted using acidified acetonitrile (containing 1% v/v formic acid) and subsequently purified with octadecylsilane (C₁₈) prior to sample analysis. Ultrahigh performance liquid chromatography coupled with tandem mass spectrometry was operated in positive and negative ionization switching mode. Amicarbazone and carfentrazone‐ethyl were detected in the positive mode (ESI+), while sulfentrazone and thiencarbazone‐methyl were detected in the negative mode (ESI?). All compounds were successfully separated in less than 3.0 min. Further optimization achieved desired recoveries ranging from 74.5 to 102.1% for all analytes with relative standard deviation values ≤17.2% in all tested matrices at three levels (10, 100, and 500 μg/kg). The limits of detection for all compounds were ≤2.3 μg/kg, and the limits of quantitation did not exceed 7.1 μg/kg. The developed method showed excellent linearity (R² ≥ 0.994) and was proven to be highly efficient and reliable for the routine monitoring of triazolone herbicides in cereals.     

Mass calibration of a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer including the rise time of the delayed extraction pulse

To utilize fully modern MALDI-TOF and TOF/TOF mass spectrometers with mass resolution exceeding 10,000 and 2 ppm precision of flight time measurements for high mass accuracy, the model of ion motion used in the mass calibration equation must be expanded. The standard three-term equation providing up to 5-10 ppm (rms) mass accuracy with internal standards was modified with an additional term accounting for the finite rise time of the high-voltage extraction pulse. This new four-term calibration equation minimizes the effect of systematic error resulting from the fact that ion velocities are mass dependent due to the rise time of the extraction pulse. Applying this new calibration equation to a mass spectrum obtained in an axial MALDI-TOF MS containing 70 peaks (sodiated PEG), each with a signal-to-noise ratio greater than 100, a mass accuracy of 1.6 ppm (rms) was obtained over the mass range 1.0-4.0 kDa compared with 3.6 ppm (rms) with the standard three-term equation. The physical basis of the effects of the finite extraction pulse rise time on mass calibration is examined for axial MALDI-TOF mass spectrometers, as well as for orthogonal acceleration TOF mass spectrometers.     

高效液相色谱–串联质谱法同时测定土壤中8种杀菌剂残留

建立高效液相色谱-串联质谱法同时测定土壤中戊唑醇、腈菌唑、腈苯唑、氟硅唑、三唑酮、丙环唑、烯唑醇、苯醚甲环唑8种杀菌剂残留量的方法。采用QuEChERS样品前处理方法对土壤样品进行提取、净化和富集,用电喷雾离子源、正负离子扫描,以多反应监测(MRM)模式进行定性和定量分析。在优化的实验条件下,8种杀菌剂的质量浓度在0.01~0.50 mg/L范围内与色谱峰面积均成良好的线性关系,相关系数均大于0.995,方法检出限为0.005~0.010 mg/kg。样品平均加标回收率为85.6%~102.2%,测定结果的相对标准偏差为4.6%~13.2%(n=5)。该方法操作简便,灵敏度和准确度高,满足土壤中戊唑醇等8种杀菌剂残留量的测定要求。     

基体归一定量技术在激光烧蚀-等离子体质谱法锆石原位多元素分析中的应用

探讨了内标法和基体归一法校准的基本原理。基体归一校准法的基本步骤为:先用简单外标法测得样品中尽可能全的主、次、痕量元素含量,氧化物加和后进行100%归一,得到灵敏度校正系数,对所有元素的测定结果进行修正。修正结果的可靠性在很大程度上取决于测定元素是否"完全"。由于锆石的基体元素组成简单且易于测定,很适合用基体归一法校准。在激光剥蚀-电感耦合等离子体质谱法(LA-ICP-MS)微区原位分析中,应用基体归一校准法的最大优点是:可以避免预先用其它微区分析技术对未知样品中的内标元素进行定量。该技术可适用于具有环带结构、难以找到均匀分布的内标元素的地质样品的元素空间分布测定。在高分辨ICP-MS(Element2)和NewWave-UV-213激光系统上,应用基体归一定量技术同时分析了锆石中主、次、痕量共54种元素。对未知锆石样品的分析,基体归一法与内标法结果的一致性令人满意。分析德国蛇纹岩标准玻璃ATHO-G中相对误差<25%的有52个元素,<10%的有36个元素;大多数元素的相对标准偏差<10%。     

Enhanced spectrophotometric determination of chromium (VI) with diphenylcarbazide using internal standard and derivative spectrophotometry

In the present work, erioglaucine A was applied as internal standard to enhanced spectrophotometric determination of chromium (VI) with diphenylcarbazide. The following procedure was used: (1) addition of internal standard and formation of ion pairs of Cr (VI) with benzyltributylammonium bromide (BTAB) (sample volume 100 ml), (2) extraction to 10 ml of methylene chloride, (3) evaporation in nitrogen stream, and (4) redissolution in a micro-volume with addition of diphenylcarbazide for color development (final volume 200 mul). The preconcentration factor achieved was about 400 and it was shown that, using internal standard, the analytical errors due to sample treatment were reduced. The analytical signals for chromium and internal standard were obtained at 591.30 and 653.50 nm from first derivative spectra, normalized against (1)D(653.50nm). The analytical characteristics evaluated were: detection limit = 0.06 mug l(-1), quantification limit = 0.19 mug l(-1), precision for 1 mug l(-1) 14.2%, and for 10 mug l(-1) 3.2%, correlation coefficient of linear regression was 0.9985. The proposed procedure was applied to determination of chromium (VI) in tap water. Total chromium was determined by electrothermal atomic absorption spectrometry, the recovery of hexavalent chromium added was then evaluated and compared with the results of the proposed procedure. In this experiment, good agreement was obtained between results obtained by the two methods.     

Determination of phthalates in wine by headspace solid-phase microextraction followed by gas chromatography-mass spectrometry. Use of deuterated phthalates as internal standards

This study proposes the use of deuterated phthalates as internal standards for the accurate determination of phthalates in wine by headspace solid-phase microextraction followed by gas chromatography-mass spectrometry. Unlike other internal standards proposed previously such as benzyl benzoate, deuterated phthalates enabled matrix-error free determinations to be performed without standard addition because statistically equal slopes were obtained for synthetic, white, rose and red wines. The relative standard deviation values under intermediate precision conditions ranged from 0.24 to 4.6%, and detection limits below 35 ng L(-1) were obtained. Recovery values were around 100% in most of cases and the method provided similar results to standard addition. Finally, the method was used to screen phthalate levels in 10 wine samples.     

氟喹诺酮三唑酮衍生物抗增殖活性的CoMFA模型

应用比较分子力场分析法(CoMFA)研究了18种氟喹诺酮三唑啉酮衍生物对人白血病HL60细胞的体外抗增殖活性(pH)。建立的模型在高相关系数值(R2=0.969)和交叉验证系数值(R2cv=0.473)方面显示出良好的相关和预测能力。空间场和静电场对pH的贡献分别为58.5%和41.5%。基于CoMFA等高线图,揭示了该系列化合物抗增殖活性的一些关键结构因素,如疏水作用、空穴契合、库仑力及氢键等。这些结果为理解其作用机制、设计具有高抗增殖活性的新型氟喹诺酮三唑啉酮类化合物以及预测其活性提供了有益的理论参考。     

土壤、沉积物系列标准物质中38种元素的ICP-MS定值

探讨了电感耦合等离子体质谱测定土壤元素的基体效应及元素间的基体干扰，采用模拟土壤元素天然组成比值的校正溶液，利用^115In-^103Rh双内标校正系统有效地抑制了分析信号的动态漂移，建立了测定土壤中元素的ICP－MS方法；对GBW07410－07416土壤、沉积物系列标准物质进行定值，测定结果与XRF分析结果比较，同时用于GBW07404、GBW07405、GBW07408、GBW07309管理样分析，结果令人满意。     

食品中三唑酮的酶联免疫吸附分析

制备人血清白蛋白和三唑酮的结合物作为免疫原,免疫兔子获得了抗三唑酮的抗体,并建立了三唑酮的酶联免疫吸附分析法。此方法被成功的应用于黄瓜、梨等食品中三唑酮的分析,最低检出限为40ng/g样品,回收率为92.44％～98.18％。并与气相色谱分析结果有很好的一致性。     

电感耦合等离子体质谱法(ICP-MS)测定高纯氧化铒中稀土杂质

从同位素的选择、基体效应,内标元素的选择及仪器工作条件等方面对实验参数进行了优化,重点研究了等离子体功率及仪器分辨率的改变对铒基体所形成的氢化物多原子离子干扰的影响。通过提高等离子体功率、改变仪器分辨率及数学方程校正等方法,减少和剔除了ErH对Ho和Tm测定的干扰。实验中选取Cs为内标元素,测定了不同含量的高纯氧化铒样品。分析结果与标准加入法结果进行了比较,之间无显著性差异。