顶空气相色谱法测定尿素中甲醇

本文采用顶空进样方式,DB-624毛细管柱,FID检测器,测定尿素中甲醇残留量。结果在0.4～200μg/mL质量浓度范围内具有良好的线形关系,相关系数大于0.9999,平均回收率为在92.5%～98.6%之间,变异系数小于2%,检测限为0.2μg/mL。     

电感耦合等离子体发射光谱法测定切削液中铁、铜、铝元素含量

本文介绍了利用电感耦合等离子体发射光谱法(ICP-OES)同时快速测定切削液中铁、铜、铝元素的方法。确定各元素分析谱线为:铁238.204nm、铜327.393nm、铝396.151nm。检出限分别为铁0.010μg/mL,铜0.003μg/mL,铝0.006μg/mL,相对标准偏差(RSD,n=11)均小于5%,加标回收率在94～105.5%之间。此方法测定结果快速准确可靠,可用于企业实际生产检测需要。     

用火焰原子吸收光谱法测中草药中的金属元素

在微波消解罐内用硝酸消化样品,采用火焰原子吸收光谱法对9种中草药中的K、Na、Mg、Mn、Fe、Zn、Cu七种金属元素进行分析测定,并研究了最佳实验条件。在选定条件下,钾的检测限为0.0019μg/mL,钠的检测限为0.0077μg/mL,镁的检测限为0.0024μg/mL,铁检出限为0.0047μg/mL,锌检出限为0.0032μg/mL,铜检出限为0.0052μg/mL,锰检出限为0.0028μg/mL,相对标准偏差为0.54%～3.2%,回收率为94.8%～101.7%。用于中草药中金属元素的测定,简便、省时、准确,结果满意。     

UPLC同时测定决明子中橙黄决明素、大黄素、大黄酚和大黄素甲醚的含量

建立UPLC同时测定决明子中橙黄决明素、大黄素、大黄酚和大黄素甲醚含量的方法,采用ACQUITY UPLCBEH-C18色谱柱(2.1 mm×50 mm×1.7μm),乙腈和0.1%磷酸水溶液为流动相,采用梯度洗脱,流速为0.6 mL/min,检测波长为284nm。结果表明橙黄决明素、大黄素、大黄酚和大黄素甲醚分别在3.002～30.02μg/mL、2.500～25.00μg/mL、10.430～104.30μg/mL和5.916～59.16μg/mL的浓度范围内均有良好的线性关系(r=0.999 9),回收率均大于95%,RSD均小于2%。该方法快速,准确,重现性好,可用于测定决明子中橙黄决明素、大黄素、大黄酚和大黄素甲醚的含量。     

全自动固相萃取-气相色谱质谱法监测地表水中的5种有机磷类农药残留量

建立全自动固相萃取-气相色谱质谱法监测地表水中的5种有机磷类(对硫磷、甲基对硫磷、马拉硫磷、内吸磷、乐果)农药残留量的检测方法。采用全自动固相萃取技术,选择HLB固相萃取柱对地表水样进行富集和净化;采用多反应监测模式(MRM)经气相色谱质谱联用仪(GC-MS)对样品进行测定,外标法定量。5种有机磷类农药残留量的质量浓度在0.02～2.0μg/mL范围内线性关系良好,线性相关系数均大于0.995,检出限如下:对硫磷:0.014μg/mL、甲基对硫磷:0.010μg/mL、马拉硫磷:0.011μg/mL、内吸磷:0.018μg/mL、乐果:0.008μg/mL。该方法的平均回收率在82.7%～94.8%之间,重复性与精密度测定结果的相对标准偏差均小于5.0%(n=6)。该方法灵敏度与准确度高,自动化程度高,适用于地表水中有机磷类农药残留的监测。     

顶空-气相色谱法测定卷烟主流烟气粒相物中吡啶

为研究气相色谱测定卷烟主流烟气粒相物中吡啶含量,采用碳酸钠水溶液作基质校正剂,通过顶空进样、DB-WAXETR色谱柱分离、火焰离子化检测器检测。结果表明:吡啶在0.20~16.20μg/mL质量浓度范围内线性拟合度为0.9998,加标回收率在98.4%~104.7%之间,定量限为0.08μg/支,RSD小于5%,该方法可以快速、准确地测定卷烟主流烟气粒相物中吡啶。     

茶叶中多菌灵和甲萘威农药残留量的测定

采用高效液相色谱法测定茶叶中多菌灵和甲萘威农药残留。通过乙腈提取凝胶渗透色谱净化(GPC)和在线浓缩方式预处理;样品检测条件:色谱柱为WatersC18柱(3.0×250mm,5μm),采用乙腈和水为流动相进行梯度洗脱,柱温30℃,流速0.5mL/min,PDA检测器,检测波长为285.2nm和220.3nm,进样量5μL。回收率为84.5%～103.2%;RSD为3.2%～4.5%;多菌灵的农药检测限为0.1μg/mL、甲萘威的农药检测限为0.03μg/mL。     

高效液相色谱法检测鱼肝中维生素A

鱼肝经添加无水硫酸钠研磨、均质后,用无水乙醚提取维生素A(视黄醇,Retinol),用高效液相色谱法检测。流动相:乙腈:甲醇=80:20,流速:0.8mL/min,柱温:40℃,紫外检测波长325nm,进样量20μL。该方法浓度检测低限0.007μg/mL,浓度定量低限0.023μg/mL,在0.05μg/mL至10.0μg/mL之间线性良好,相关系数0.9998,回收率为91～96%,相对标准偏差为2.0～3.1%。该方法步骤简易、结果准确。     

石墨炉原子吸收光谱测定三甲基镓中痕量元素

介绍一种石墨炉原子吸收光谱测定三甲基镓的方法。用乙醇分解三甲基镓,分解产物的水解溶液用于检测四种痕量元素Cu、Fe、Ms、Si。分解和测定过程的相对标准偏差小于24.0％。检测限:Cu为0.4μg/g,Fe为0.4μg/g,Mg为0.09μg/g,Si为0.4μg/g。     

UPLC测定黄连中盐酸小檗碱和盐酸巴马汀的含量

建立UPLC测定黄连中盐酸小檗碱和盐酸巴马汀含量的方法。采用ACQUITY UPLC BEH-C18色谱柱(2.1mm×50 mm×1.7μm),以乙腈-0.05mol/L磷酸二氢钾溶液为流动相,梯度洗脱,流速为0.2 mL/min,检测波长为350 nm。结果表明盐酸小檗碱和盐酸巴马汀分别在0.037 2～0.297 6μg/mL,0.008 2～0.065 6μg/mL的浓度范围内均有良好的线性关系(r=0.9999),回收率均大于95%,RSD均小于2%。该方法快速、准确、重现性好,可用于测定黄连中盐酸小檗碱和盐酸巴马汀的含量。     

反相液相色谱法测定复方泰妙菌素注射液中泰妙菌素、磺胺嘧啶钠的含量

目的：建立反相液相色谱法测定复方泰妙菌素注射液中泰妙菌素、磺胺嘧啶钠的含量的方法。方法：采用Shim—packCLC—ODS柱（150mm×6mm,5μm）,流动相为80％乙腈-0．7％磷酸氢二铵（体积比为0．3：0．7）并用氨试液调节pH至8．0±0．1。流速为1．0mL／min,检测波长为208nm,柱温为40℃。结果：在此色谱条件下两者能完全分离,泰妙菌素在5-40μg／mL和磺胺嘧啶钠在10—80μg／mL的范围内浓度与峰面积呈良好的线性关系,回归方程和相关系数分别为：A=47205．9p＋2003．72,R=0．9999;A=77050p＋5514．75,R=0．9999。泰妙菌素和磺胺嘧啶钠的平均回8：4分别为99．99％、99．7％;RSD分别为0．70％、0．95％。结论：方法简便、快速、准确,可用作复方泰妙菌素注射液的含量测定。     

五种磺胺类药物残留的快速测定

采用反相高效液相色谱法(RP-HPLC),同时快速测定五种磺胺类药物残留。在Waters Nova-Pak C18 柱上,用紫外或PDA检测器,流速1.0 mL/min,柱温35℃,于267 nm波长处检测,流动相为5 mmol/L NaH2PO4 溶液-乙腈溶液(体积比为70∶30),磷酸调pH 3.0。完成整个色谱分离只须3.5 min,比原来的11 min大大减少了分离时间。     

水产品中四环素类抗生素残留量的高效液相色谱测定方法

本文建立了高效液相色谱(HPLC)检测水产品中3种四环素类抗生素残留量的方法。采用4%高氯酸溶液提取样品中的残留抗生素,经浓缩处理,以乙氰和0.01mol·L-1NaH2PO4(18∶82,v/v)为流动相,流速1mL·min-1,3种抗生素组分峰能与杂质峰完全分开,检测波长为355mm。在50~1000μg·mL-1范围内,峰面积与抗生素浓度呈良好的线性关系(r2>0.99),以测量的3倍标准偏差计算方法的检出限分别为0.045μg·g-1(土霉素)、0.041μg·g-1(四环素)和0.080μg·g-1(金霉素)。平均加标加收率分别为96.5%(土霉素)、87%(四环素)和73.2(金霉素)。精密度(RSD)小于5%。实验检测了几种常见水产品样品的四环素类抗生素残留量,发现在本检出水平下被检测的几种鱼和虾样品均未能检出。     

体外壳聚糖-明胶-生长因子缓释支架对骨髓间充质干细胞增殖的影响

制备具有缓释功能的壳聚糖-明胶-碱性成纤维细胞生长因子(bFGF)-肝细胞生长因子(HGF)三维大孔支架,探讨两种生长因子在体外对骨髓间充质干细胞(BMSCs)增殖的协同作用。方法:采用冷冻干燥法,将不同比例的壳聚糖、明胶、bFGF和HGF依次混合,使其成为具有一定孔径的三维缓释支架。取SD大鼠乳鼠股骨和胫骨骨髓,分离、培养BMSCs。取生长状态良好的第三代BMSCs,将其接种于96孔板后,加入支架混合培养,5d后进行MTT细胞增殖测定。结果:在与含1μg/mL的bFGF支架混合培养,以及与同时含1μg/mL的bFGF、1μg/mL的HGF支架混合培养后,BMSCs增殖明显(P<0.05),但这二组间无统计学差异(P>0.05)。分别与含0.1μg/mL的bFGF支架、0.01μg/mL的bFGF支架、1μg/mL的HGF支架混合培养后,细胞增殖无统计学意义(P>0.05)。结论:壳聚糖-明胶可作为生长因子缓释支架材料;bFGF具有促进BMSCs增殖的作用,促进作用的大小与加入bFGF的量有关;HGF对BMSCs不具有增殖作用;在实验浓度范围内bFGF和HGF体外促进BMSCs增殖上不具有协同性。     

Triton X-100-5-Br-PADAP分光光度法选择性测定乳粉中微量铁

报道了以2-(5-溴-吡啶偶氮)-5-二乙氨基酚(5-Br-PADAP)为显色剂,应用分光光度法高选择性测定铁(Ⅲ)的新方法。实验结果表明,在pH4.0的乙醇介质中和Triton X—100、盐酸羟氨存在下,以746nm为测定波长,可选择性测定铁(Ⅲ)含量。本法线性范围为0～1.3μg/ml,表观摩尔吸收系数为2.94×10~4L·mol~(-1)·cm~(-1),批内和批间精密度cv%分别为1.2%、2.3%,平均回收率为98.9%。已用于乳粉中微量铁的直接测定,常见共存成分对测定无干扰。     

Simultaneous determination of methocarbamol and aspirin in presence of their pharmacopeial-related substances in combined tablets using novel HPLC-DAD method

Objective and Significance: Methocarbamol (MET) and aspirin (ASP) are widely used as a muscle relaxant combination. The USP reports guaifenesin (GUA) and salicylic acid (SAL) as related substances and hydrolytic products of MET and ASP, respectively. This work aimed at developing and validating a simple and sensitive RP-HPLC method for the determination of both drugs as well as their related substances (at their pharmacopeial limits) in their bulk powders, laboratory prepared mixtures, and MET-ASP combined tablets. Methods and Results: Chromatographic separation was achieved in less than 9?min with the required resolution, peak symmetry, and accuracy on C₁₈ column using isocratic elution system of diluted acetic acid (pH 3.2): acetonitrile at the ratio of 79: 21, v/v, at a flow rate of 1?mL/min. Detection was achieved with photodiode array at 233?nm for MET, GUA, and SAL and at 273?nm for ASP. The developed method has been validated as per ICH guidelines and the calibration plots were linear over the concentration ranges of 2–150, 0.4–30, 25–450, and 0.2–27?μg/mL for MET, GUA, ASP, and SAL, respectively. Conclusion: The optimized method proved to be specific, robust and precise for the quality control of the studied drugs in pharmaceutical preparations to ascertain that their related substances are not exceeding the permitted pharmacopeial limits.     

Does P-glycoprotein contribute to amphotericin B epithelial transport in Caco-2 cells?

Introduction: Amphotericin B (AmB) is a highly efficacious therapeutic for invasive fungal infections and protozoal diseases. Increasing prevalence of these conditions warrants the development of an oral AmB formulation. Efflux transporters, such as the ABCB1 gene product P-glycoprotein, affect the oral bioavailability and disposition of a range of clinically relevant compounds. At present, it remains to be determined whether AmB is a substrate of P-glycoprotein mediated efflux. The objective of this study was to determine whether P-glycoprotein contributes to the epithelial transport of AmB in a Caco-2 cell model.

Methods: Stimulation of P-glycoprotein ATPase activity was assessed using membranes containing human recombinant P-glycoprotein. An ABCB1 knockdown Caco-2 cell model was employed to determine non-toxic concentrations of AmB. AmB cellular association, following a 180?min incubation, was determined using an high performance liquid chromatography-ultraviolet (HPLC-UV) assay.

Results: At the concentrations investigated, AmB did not stimulate P-glycoprotein ATPase activity. Non-toxic concentrations of AmB were 1?μg/mL–5?μg/mL; these were used in subsequent experiments. No significant difference in AmB cellular association was observed for ABCB1 small interfering ribonucleic acid transfected and non-transfected Caco-2 cells, following a 180?min incubation with 1?μg/mL and 2.5?μg/mL AmB. However, significantly greater AmB was associated with transfected cells as compared to non-transfected cells, when cells were incubated with 5?μg/mL AmB.

Conclusions: These results suggest that AmB is not a substrate of P-glycoprotein mediated efflux in this Caco-2 cell model. P-glycoprotein is not expected to be a major barrier to the oral absorption and disposition of AmB.     

A validated stability indicating LC method for Nateglinide

A simple, isocratic, rapid and accurate reverse phase high-performance liquid chromatography (RP-HPLC) method was developed for the quantitative determination of Nateglinide. The developed method is also applicable for determination of related substance in bulk drugs. The chromatographic separation was achieved on a Hypersil C18 (250 × 4.6 mm 5 μm) column using aqueous mixture of 0.025 M potassium hydrogen phosphate and 0.1% triethyl amine, v/v (pH 3.0 with dilute phosphoric acid)—methanol (25:75, v/v) as a mobile phase. Solution concentrations were measured on a weight basis to avoid the use of an internal standard. The chromatographic resolutions between Nateglinide and its potential impurities A and B were found to be greater than four. Forced degradation studies were performed for Nateglinide using acid (0.5 N hydrochloric acid), base (0.5 N sodium hydroxide), oxidation (3% hydrogen peroxide) heat (60°C) and UV light (254 nm). The limit of detection and limit of quantification of Nateglinide, impurities A and B were found to be 0.05 and 0.15 μg /mL, respectively for 20 μL injection volume. The percentage recovery of Nateglinide was ranged from 98.4 to 100.9. The percentage recovery of impurities in Nateglinide sample was ranged from 96.8 to 103.5. The developed RP-HPLC method was validated with respect to linearity, accuracy, precision, robustness, and forced degradation studies prove the stability indicating power of the method.     

微波消解-冷原子荧光光谱法测定V2O5-WO3/TiO2系脱硝催化剂中汞的含量

该文采用酒石酸+氢氟酸+硝酸体系微波消解处理V₂O₅-WO₃/TiO₂脱硝催化剂试样,以氢化物发生-冷原子荧光光谱法(HG-AFS)测定其中汞的含量。文中探讨原子化器炉温、原子化器高度、载气及屏蔽气流量及硼氢化钾-氢氧化钠浓度等关键参数对汞测定的影响,并通过系列试验确定上述关键参数的最优解:还原剂浓度为0.2 g/L(硼氢化钾)–2.0 g/L(氢氧化钠),载气和屏蔽气流量分别为600 mL/min和800 mL/min,原子化器炉温200℃,原子化器高为10 mm。共存元素干扰试验表明,在该实验条件下,少量As(Ⅲ)的干扰可加入高锰酸钾(1.0 g/L)将其氧化成As(Ⅴ)得以消除,Pb(Ⅱ)的干扰可加入1.0 mL硫酸(1+5)生成硫酸铅沉淀消除。汞的浓度在0~2.0μg/L范围内线性相关系数为0.9997,方法检出限为0.02μg/L。方法用于实际样品分析,相对标准偏差(RSD,n=7)小于4.0%,加标回收率为95%~104%。