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固相微萃取-高效液相色谱联用测定环境水样中双酚A的自由溶解态浓度 总被引:6,自引:1,他引:6
应用可忽略耗损固相微萃取与高效液相色谱联用技术测定了环境水样中双酚A的自由溶解态浓度。为了获得高的灵敏度并减小环境因素(如温度和搅拌等)的影响,采用商品化固相微萃取纤维CW/TPR进行平衡采样。在环境水样常见pH(5~8)、缓冲容量(5~200mmol/L)和盐度(0~500mmol/L)条件下,4h可以达到萃取平衡。100mL样品足以避免样品耗损。以配制在250mmol/L NaCl和125mmol/L磷酸盐溶液(pH6.4)中的双酚A标准溶液进行校准,可以将缓冲液(0~200mmol/L)、盐度(0~500mmol/L)和pH(5.7~8.5)的影响控制在15%偏差范围以内。如需更准确的测定,也可以对样品pH值的影响加以校正。pH为6.4时,方法的线性范围为0.1~250μg/L,检出限为0.03μg/L,相对标准偏差(5μg/L,n=3)为1.1%。采用本方法测定了污水处理厂排水口的双酚A的自由溶解态浓度。 相似文献
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糊精介质中西酞普兰的毛细管电泳手性分离与定量测定 总被引:1,自引:0,他引:1
以糊精作为毛细管电泳手性分离选择剂,对药物西酞普兰对映体的分离进行研究。考察了糊精浓度、缓冲液体系离子强度和pH及分离电压对对映体分离的影响。在糊精7.0%(m/V)、磷酸盐80mmol/L(pH5.4)的运行缓冲液中,分离电压20kV时,西酞普兰对映体分离度达3.9,同时对拆分机理进行了初步探讨。测定S-(+)-西酞普兰原料药中R-(-)异构体的含量,在0.05~4.00g/L浓度范围内线性关系良好,R-(-).西酞普兰与S-(+)-西酞普兰的检出限分别为25.3mg/L和27.3mg/L,线性相关系数均在0.9970以上;RSD低于3.2%。 相似文献
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通过对缓冲体系、缓冲液浓度、酸度、乳酸钙浓度、乙胺浓度、电泳电压和进样时间的优化选择,用石英芯片电泳一紫外检测法分离了纯人白蛋白和人运铁蛋白;在75mmol/L硼酸盐(pH10.55)(含0.8mmol/L乳酸钙、1%(φ)乙胺)运行缓冲液中,上述两组分在3min内完全分离;纯人白蛋白和人运铁蛋白的线性范围分别为1.0~15.0g/L和1.0~10.0g/L;检出限(S/N=3)均为0.5g/L,应用于临床尿蛋白分离测定,并与Helena琼脂糖凝胶电泳仪电泳结果进行比较,获得一致结果。 相似文献
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反相高效液相色谱法测定人血浆中利培酮及其代谢物的质量浓度 总被引:3,自引:0,他引:3
建立了测定人血浆中利培酮及其活性代谢物9-羟利培酮质量浓度的反相高效液相色谱方法。用Zor-baxODSC18色谱柱,以V(甲醇):V(水):V(1mol/L醋酸铵):V(3mol/L氨水)=300:50:3:1为流动相,检测波长为280nm,流速为0.8mL/min。利培酮的线性范围为2~600μg/L(r=0.996),回收率为(98.2±3.5)%,日内与日间的标准偏差分别为4.12%和4.83%;9-羟利培酮的线性范围为2~800μg/L(r=0.998),回收率为(97.8±3.8)%,日内与日间的标准偏差分别为4.28%和4.81%。 相似文献
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毛细管电泳法测定单胺氧化酶活性 总被引:3,自引:1,他引:2
应用毛细管电泳技术,建立了快速测定单胺氧化酶(MAO)活性的方法。研究对分离缓冲液pH值、浓度、毛细管表面改性剂十四烷基三甲基溴化铵(TTAB)浓度等影响因素进行优化,探讨了方法的可行性,确立了最佳分离条件。以70cm×50μm(i.d.)未涂敷熔融石英毛细管为色谱分离柱,运行电压15kv,运行缓冲液:0.5mmol/LTTAB,磷酸盐缓冲液(50mmol/L,pH 10.5);紫外检测波长:214nm。MAO催化犬尿胺(Kyn)反应的产物4-羟基喹啉(4-HQ)的浓度和峰面积的线性范围为5~1000μmol/L,相关系数为0.9997,相对标准偏差(RSD)小于5.6%(n=5),检出限为2μmol/L(S/N=3)。实验证明,此方法可以用于生物样品中MAO催化活性的检测。 相似文献
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离子交换色谱法检测离子液体中阴离子 总被引:3,自引:0,他引:3
建立了用阴离子交换分离柱、化学抑制模式、电导检测测定系列离子液体中BF4^-阴离子及其他杂阴离子(F^-、Cl^-、Br^-)含量的方法,并用于在线监控离子液体合成工艺中阴离子杂质含量。确定淋洗液组成为1.6mmol/L Na2CO3+3.9mmol/L NaHCO3,流速为0.6mL/min。本方法对所测阴离子检出限分别为50μg/L(F^-、Br^-)和80μg/L(BF4^-);线性范围在3个数量级以上;r〉0.999;回收率在98%~102%之间。方法用于对离子液体小试工艺样品分析及过程监控时,结果满意,样品的RSD小于2.6%(n=6)。 相似文献
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《Biomedical chromatography : BMC》2018,32(9)
A highly selective and sensitive liquid chromatography–tandem mass spectrometry (LC MS/MS) method was developed for the quantification of metronidazole (MTZ) in human feces. The analyte was recovered from feces after liquid–liquid extraction with ethyl acetate and separated on Waters Symmetry® C18 (100 × 4.6 mm, 5μm) column using 0.1% formic acid in water and acetonitrile (40:60, v/v) as the mobile phase. A stable‐deuterated internal standard metronidazole‐d4 (MTZ‐d4) was used in the study. Mass analysis was performed on a triple quadrupole mass spectrometer in the positive electrospray ionization mode. A linear response function of MTZ was established in the concentration range of 0.50–250 ng/g, based on dry mass. The mean extraction recovery of MTZ (97.28%) and MTZ‐d4 (96.76%) from spiked feces samples was consistent at higher as well as lower concentrations. Post‐column infusion analysis showed no ion‐suppression/enhancement effects and the mean IS‐normalized matrix factor ranged from 0.986 to 1.013. Spiked feces samples stored at −20 and − 70°C for long‐term stability were stable for at least 3 months, while extracted samples (dry and wet extracts) were stable up to 24 h. The method was applied to determine MTZ in feces of 12 healthy Indian subjects. 相似文献
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高效液相色谱-串联质谱联用测定蜂王浆中的三种硝基咪唑类残留 总被引:9,自引:0,他引:9
建立了高效液相色谱-串联质谱联用测定蜂王浆中甲硝唑(MTZ)、二甲硝唑(DMZ)和洛硝哒唑3(RNZ)种硝基咪唑类残 留的方法。使用氢氧化钠溶液溶解样品后,以乙酸乙酯液液萃取提取蜂王浆样品中的硝基咪唑类残留物。该法简便快捷, 适合大批量样品处理。采用氘代二甲硝唑作为内标和利用高选择性反应监测(H-RSM)技术,降低了基质干扰,增加了定量的 准确性。实验结果表明DMZ检测下限可以达到1.0 μg/kg,MTZ和RNZ检测下限可以达到0.5 μg/kg(S/N大于5);DMZ 定量下限可以达到2.0 μg/kg,MTZ和RNZ定量下限可以达到1.0 μg/kg(S/N大于10)。线性范围为2.0~200 μg/L, 添加回收率为96.6%~110.6%(内标校正),相对标准偏差(RSD)为2.1%~7.4%。 相似文献
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高效液相色谱法分析人血清中硫唑嘌呤和巯嘌呤的浓度 总被引:3,自引:0,他引:3
建立了用HPLC同时测定人血清中硫唑嘌呤(AZP)和6-巯基嘌呤(6-MP)浓度的方法。血清样品经乙腈除蛋白后在常压和37℃下用氮气吹干,残余物用100μL洗脱液溶解,离心后上清液直接进样。以SpherisorbC18固定相,采用梯度洗脱,从V(乙腈)∶V(0.01mol/L磷酸二氢钾)=3∶97经5min时变为18∶82,15min后再变为50∶50,检测波长开始为325nm,10min后为278nm,甲硝唑(MNZ)为内标。AZP和6-MP平均回收率分别为(100.6±4.2)%和(102.4±4.5 )%。 相似文献
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To simultaneously measure 3-methoxy-4-hydroxyphenylglycol (MHPG), 5-hydroxyindoleacetic acid (5HIAA), and homovanillic acid (HVA) in human cerebrospinal fluid (CSF), we used an acetonitrile protein precipitation, reversed-phase high-performance liquid chromatography with coulometric detection, and 3-methoxy-4-hydroxyphenyllactic acid (MHPLA) as an internal standard for all three metabolites. MHPG, 5HIAA, HVA, and MHPLA were stable for one month when stored in CSF at -70 degrees C. Three determinations were made in triplicate for each of seven subjects over a 30-day storage period and the coefficients of variation within subject for these determinations ranged from 0.075 to 0.165 for MHPG, 0.045 to 0.148 for 5HIAA and 0.053 to 0.181 for HVA. Means and standard deviations of CSF concentrations were 10.7 +/- 3.0 ng/ml for MHPG, 22.4 +/- 9.9 ng/ml for 5HIAA, and 39.9 +/- 21.4 ng/ml for HVA. This method provides simple sample preparation, sensitivity, and cost advantages, as well as simultaneous extraction and quantitation of MHPG, 5HIAA, and HVA using an internal standard. 相似文献
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Sastre Toraño J Rijn-Bikker Pv Merkus P Guchelaar HJ 《Biomedical chromatography : BMC》2000,14(5):306-310
A validated new and precise reversed-phase high-performance liquid chromatographic method for the determination of melatonin in human plasma and cerebrospinal fluid, with 5-fluorotryptamine as internal standard, is described. Liquid-liquid extraction with dichloromethane was performed under alkaline conditions. After evaporation of the organic solvent, the extract was dissolved in eluent and chromatographed on a base-deactivated octadecyl column, using an eluent composed of 650 mL potassium dihydrogenphosphate solution (0.07 mol/L water), adjusted to a pH of 3.0 with a 43% phosphoric acid solution, mixed with 350 mL methanol. Fluorescence detection at an excitation wavelength of 224 nm and an emission wavelength of 348 nm was used for quantitation. Melatonin and 5-fluorotryptamine chromatographed with retention times of 5.3 and 9. 3 min, respectively. Mean recoveries of 96% (n = 10) and 95% (n = 5) were found for melatonin in plasma and cerebrospinal fluid respectively. 5-Fluorotryptamine was found to have a mean recovery of 90% (n = 10) and 82% (n = 5) in plasma and cerebrospinal fluid, respectively. The repeatability coefficients of variation for both melatonin and 5-fluorotryptamine in plasma were 4-5% [five different samples (r = 5) on two consecutive days (n = 2)], with reproducibility coefficients of 1.6-7% (n = 2, r = 5) and 0.9-4% (n = 2, r = 5) for melatonin and internal standard, respectively. In cerebrospinal fluid the repeatability coefficient of variation of the extraction procedure was 5% (n = 1, r = 5) for melatonin and 7% (n = 1, r = 5) for 5-fluorotryptamine. The correlation coefficients of the calibration curves were 0.9998 (n = 2) in plasma at a concentration range of 0.108-25.9 ng/mL and 0.9994 (n = 2) at a concentration range of 0.108-25.9 ng/mL in cerebrospinal fluid. The limit of detection was determined at 8 pg/mL which enables to measure melatonin concentrations at physiological concentrations reached during daytime. 相似文献
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《Biomedical chromatography : BMC》2018,32(8)
A highly sensitive, selective and rugged method has been described for the quantification of metronidazole (MTZ) in human plasma by liquid chromatography–tandem mass spectrometry using metronidazole‐d4 as the internal standard (IS). The analyte and the IS were extracted from 100 μL plasma by liquid–liquid extraction. The clear samples obtained were chromatographed on an ACE C18 (100 × 4.6 mm, 5 μm) column using acetonitrile and 10.0 mm ammonium formate in water, pH 4.00 (80:20, v/v) as the mobile phase. A triple quadrupole mass spectrometer system equipped with turbo ion spray source and operated in multiple reaction monitoring mode was used for the detection and quantification of MTZ. The calibration range was established from 0.01 to 10.0 μg/mL. The results of validation testing for precision and accuracy, selectivity, matrix effects, recovery and stability complied with current bioanalytical guidelines. A run time of 3.0 min permitted analysis of more than 300 samples in a day. The method was applied to a bioequivalence study with 250 mg MTZ tablet formulation in 24 healthy Indian males. 相似文献
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A simple procedure for the determination of pyrazinamide in plasma and cerebrospinal fluid in the rabbit is described. The assay involves a preliminary extraction of the drug and an internal standard, paracetamol, from the acidified sample (pH 4.2). The extract is evaporated to dryness at 45 degrees C and the residue is redissolved in methanol (50 microliters). A 25-microliters aliquot is injected into the liquid chromatograph and eluted with acetonitrile-10 mM phosphate buffer of pH 3.5 (10:90, v/v) on a 30-microns C8 pre-column linked to a 5-microns C8 reversed-phase column at ambient temperature (25 +/- 1 degree C). The eluate is detected at 215 nm. The method has been used to investigate the disposition of pyrazinamide in plasma and cerebrospinal fluid in six rabbits. 相似文献