超高效液相色谱-质谱法测定饮用水中14种氟喹诺酮类抗生素的残留量

采用超高效液相色谱-质谱法测定饮用水中的14种氟喹诺酮类抗生素的残留量。饮用水样品经Oasis HLB(200mg/6mL)固相萃取柱富集。柱上的浓集物用甲醇洗脱,洗脱液以Acquity UPLC BEH C_(18)色谱柱为分离柱,以不同体积比的0.1%(体积分数)甲酸溶液和0.1%(体积分数)甲酸乙腈溶液的混合液为流动相进行梯度洗脱,采用电喷雾正离子模式进行质谱检测。14种氟喹诺酮类抗生素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)在0.04~1.8ng·L~(-1)之间。以空白样品为基体进行加标回收试验,所得回收率在69.2%~85.2%之间,测定值的相对标准偏差(n=6)在4.5%~11%之间。     

亲水色谱柱-超高效液相色谱法测定饲料中纳多洛尔含量

用Waters AcQuity BEH Hilic亲水色谱柱-超高效液相色谱法测定了饲料中纳多洛尔的含量。样品先后2次用1%(φ)酸化甲醇溶液15,10mL超声提取,合并两次上清液,并分取5mL,通过MCX SPE小柱净化。用5%(φ)氨化甲醇溶液5mL洗脱。洗脱液在40℃用吹氮蒸干。残渣用由乙腈、0.5%甲酸溶液和水以体积比10比15比75组成的混合液1mL溶解,分取1.0μL进行色谱分析。采用亲水色谱柱为固定相及上述乙腈-甲酸溶液-水的混合液作流动相,纳多洛尔得到很好分离,纳多洛尔的质量浓度在0.01~20mg·L-1之间与峰面积呈线性关系。方法的测定下限(10S/N)为0.01mg·kg-1。用标准加入法测得回收率在78.5%~95.0%之间,测定值的相对标准偏差(n=5)均小于8%。     

高效液相色谱法测定壮阳保健品中4种硫代西地那非类药物

提出了用高效液相色谱法测定壮阳保健品中4种非法加入的硫代西地那非类药物的方法。样品用乙腈-水(1+1)溶液超声提取。用ACE C18色谱柱分离,柱温为35℃,进样量为10μL,所用流动相为由(A)三乙胺溶液-甲醇-乙腈(60+20+20)混合液和(B)三乙胺溶液-甲醇-乙腈(8+46+46)混合液,以不同体积比混合的溶液进行梯度淋洗。检测波长为230nm。4种药物的线性范围均在1.00~100mg·L-1范围内,检出限(3S/N)均为67μg·kg-1。加标回收率在92.0%~101%之间,测定值的相对标准偏差(n=6)均小于1.5%。对阳性样品进一步用LC-MS/MS确证。此外,还研究了硫代西地那非的二级质谱裂解规律和紫外光谱特征。     

固相萃取-高效液相色谱法测定鱼制品中8种杂环胺类化合物

鱼制品样品(2g)用2.0mol·L-1氢氧化钠溶液10mL超声提取20min,用二氯甲烷50mL淋洗装有15g硅藻土的层析柱,洗脱液经MCX柱进行固相萃取分离。用氨水-甲醇(10+90)混合液淋洗MCX柱,洗脱液于40℃吹氮蒸干,残渣用甲醇1.0mL溶解供色谱分析。以TOSOH TSK gel ODS-80TM色谱柱为固定相,用(A)乙腈和(B)pH 3.5的0.01mol·L-1磷酸溶液以不同体积比组成的混合液作流动相进行梯度淋洗。用二极管阵列检测器测定。8种杂环胺类化合物的质量浓度均在0.005~1.0mg·L-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.3~3.8μg·kg-1之间。以空白样品为基体进行加标回收试验,所得回收率在51.8%~93.7%之间,测定值的相对标准偏差(n=6)在0.89%~3.7%之间。     

固相萃取-高效液相色谱法测定水中洛克沙胂

建立了水中洛克沙胂固相萃取-高效液相色谱检测方法。水样pH<2时,用高分子聚合物萃取柱(Poly-Sery PSD)对洛克沙胂富集后,用乙酸乙酯和丙酮混合液(体积比4∶1)1 mL淋洗除去干扰物和柱上残留水分,柱上洛克沙胂用5 mL丙酮洗脱。洗脱液经N2吹至近干,用体积分数0.05%H3PO4溶液定容至0.50 mL于液相色谱检测。以Shimpak-ODS C18柱为分析柱,以V(甲醇):V(100mL/L甲酸溶液):V(0.02 mol/L KH2PO4溶液)=60:20:20为流动相。柱温为30℃,流速1.0 mL/min,检测波长为267 nm。在0.01~5.0 mg/L范围内相关系数大于0.999。空白水中不同浓度的加标回收率在83%~91%之间,相对标准偏差在5.1%~13%之间。方法用于检测饲料加工厂和养鸡场厂房周边的排污废水,部分样品中检出洛克沙胂,质量浓度范围在0.041~0.053μg/L之间。     

固相萃取-高效液相色谱-串联质谱法同时测定不同基质保健食品中10种减肥药物

采用固相萃取-高效液相色谱-串联质谱法同时测定不同基质保健食品中10种减肥药物。保健食品样品采用甲醇超声提取,经Oasis HLB固相萃取柱净化,以Zorbax-SB-C_(18)色谱柱为分离柱,以不同体积比的10mmol·L~(-1)乙酸铵-0.1%(体积分数)甲酸溶液和乙腈的混合液为流动相进行梯度洗脱,采用电喷雾正离子源多反应监测模式检测。10种减肥药物的质量浓度均在1.0~100.0μg·L~(-1)内与其对应的峰面积呈线性关系,方法的检出限(3S/N)为1.2~3.8μg·kg~(-1)。以空白样品为基体进行加标回收试验,所得回收率为79.5%~106%,测定值的相对标准偏差(n=6)为2.5%~9.7%。     

反相液相色谱法测定农药中氯菊酯

建立反相液相色谱法测定农药中氯菊酯含量的方法.采用C18反相色谱柱(250 mm×4.6 mm,5μm),以甲醇–水溶液(体积比为9:1)为流动相,流量为0.8 mL/min,检测波长为230 nm,柱温为35℃,进样体积为10μL,以外标法测定农药中氯菊酯的含量.氯菊酯的质量浓度在1～200μg/mL范围内与色谱峰面...     

固相萃取-超高效液相色谱-串联质谱法测定水中13种抗生素的含量

采用固相萃取-超高效液相色谱-串联质谱法测定水中13种抗生素的含量。水样中的抗生素富集于PLS固相萃取柱上,用甲醇洗脱,洗脱液进行LC分离,以Endeavorsil C18色谱柱为分离柱,以不同体积比的0.4%(体积分数)甲酸-水溶液和甲醇-乙腈(40+60)溶液的混合液为流动相进行梯度洗脱。质谱分析中,采用电喷雾正离子源多反应监测模式检测。13种抗生素均在一定的质量浓度范围内与其对应的峰面积呈线性关系,方法的检出限(3S/N)在0.4~1.5ng·L~(-1)之间。以空白样品为基体进行加标回收试验,所得回收率在70.4%~101%之间,测定值的相对标准偏差(n=5)在1.1%~4.8%之间。     

固相萃取-高效液相色谱-原子荧光光谱法联用测定水中无机汞(Ⅱ)及有机汞

采用固相萃取-高效液相色谱-原子荧光光谱法联用技术测定了水样中无机汞及有机汞。水样流经以DDTC溶液改性的C18固相萃取小柱。用含有10%(体积分数)乙腈的混合洗脱液4mL,分4次,以1~2mL·min-1流量从小柱上将3种形态的汞洗脱。收集洗脱液,混匀,过滤后通过Venusil MP C18色谱柱,用乙腈、145mmol·L-1乙酸铵溶液和20mmol·L-1半胱氨酸溶液(5+45+50)混合液作为流动相进行色谱分离。根据选定的形态分析条件,用原子荧光光谱法进行测定。汞质量浓度在0.5~20μg·L-1范围内与其峰面积呈线性关系,汞(Ⅱ)、甲基汞、乙基汞的检出限(3S/N)依次为1.6,0.5,1.2ng·L-1。加标回收率在71.2%~95.2%之间,测定值的相对标准偏差(n=6)在4.9%~10%之间。     

发用防晒剂DDABDT的反相高效液相色谱法测定

建立了反相高效液相色谱法测定发用防晒剂二甲基对胺基苯甲酰胺丙基十二烷基二甲胺甲苯磺酸盐(简称DDABDT)的方法.采用的色谱条件为色谱柱Symmetry C8柱,流动相为V(乙腈):V(10 mmol/L NaAc)=65:35溶液(含体积分数0.02%三氟乙酸,pH5.04),流速1.0 mL/min;检测波长305 nm;进样量20μL.DDABDT质量浓度为0.05～1000 mg/L时,其浓度与峰面积呈良好的线性关系(R2＞0.999),检出限为0.02 mg/L(S/N=3).洗发水A中DDABDT的回收率在98.0%～102%之间,发样提取液中DDABDT的平均回收率在85%～108%之间.洗发水中DDABDT浓度测定日内和日间相对标准分别为1.2%,3.4%.头发吸附DDABDT含量测定日内和日间相对标准偏差(RSD)分别为9.1%,9.8%.同时以高效液相色谱-电喷雾离子化质谱对色谱法测定样品的DDABDT峰进行了验证.该方法已用于洗发水及头发吸附DDABDT的分析.     

Chemiluminescence detection coupled to high-performance frontal analysis for the determination of unbound concentrations of drugs in protein binding equilibrium

High-performance frontal analysis coupled with chemiluminescence detection (HPFA-CL) was developed for the determination of unbound oxacillin concentration in human serum albumin solution. The HPFA system consisted of an ISRP column and a mobile phase of 67 mM potassium phosphate buffer of pH 7.4 and ionic strength of 0.17. The luminol-H2O2-Co2+ system was used in the chemiluminescence detection. An enhancement of luminol chemiluminescence by oxacillin was investigated and employed for determining the concentration of oxacillin in the HPFA eluate. Sample solutions were directly injected onto the column; the drug was eluted as a zonal peak with a plateau region. The unbound drug concentrations were determined by using the height of the plateau. The results agreed with those obtained with conventional ultrafiltration-HPLC method. Good reproducibility was confirmed by the within run and between run RSD < or = 7.4%. HPFA-CL provided a selective method for determination of unbound drug concentration in protein binding equilibrium.     

Effect of protein binding on high performance liquid chromatography analysis of drugs with an internal-surface reversed-phase silica column

The effect of protein binding on the high performance liquid chromatography (HPLC) elution profile of drugs injected directly onto an internal-surface reversed-phase (ISRP) silica column was investigated. When a relatively large volume (greater than or equal to 100 microliters) of the sample solution containing warfarin and bovine serum albumin (BSA) was applied directly onto the ISRP column and elution was carried out with the mobile phase containing an organic modifier, two distinct peaks, both due to warfarin, appeared separated from the protein peak. The peak splitting was not observed in the case of antipyrine-BSA mixed solution, where the protein binding is weak. It was found that the drug bound at the strong-binding site on the BSA molecule was released slowly during the process of chromatography and was eluted as the first peak with a shorter retention time, while the drug bound at the weak-binding site was released quickly, and was eluted as the second peak together with the free drug. The warfarin-BSA interaction at the strong-binding site was evaluated, under minimum influence from the other binding site, from the warfarin concentration obtained from the first peak and the free warfarin concentration determined by the ultrafiltration method.     

Specific determination of unbound oxacillin in protein solution with cefoperazone by high-performance frontal analysis with chemiluminescence detection

Unbound oxacillin concentrations in human serum albumin (HSA) solutions in the presence or absence of cefoperazone were determined using high-performance frontal analysis coupled with chemiluminescence detection (HPFA-CL). The HPFA was performed on an ISRP column with 67 mM potassium phosphate buffer of pH 7.4 and ionic strength of 0.17 as the mobile phase. The luminol-H(2)O(2)-Co(2+) system was employed in the chemiluminescence detection. The detection was highly specific for oxacillin in the presence of cefoperazone. Although both drugs in HSA solutions co-eluted in the same region in HPFA, cefoperazone did not interfere with the determination of unbound concentration of oxacillin. In the solution of 100 microM HSA and 11.33 micro M oxacillin the bound percentage of oxacillin to HSA was estimated as 80.5%. Addition of 30.98 micro M cefoperazone into the HSA-equilibrated solution produced little effect on the protein binding of oxacillin. In the presence of 154.9 micro M cefoperazone, however, the bound percentage of oxacillin was significantly reduced. This specific method could be applied to the investigation of drug-drug interaction in protein binding.     

毛细管电泳-迎头分析法测定血清或血浆中氯氮平的游离浓度

采用毛细管电泳-迎头分析模式体外实验测定了人血清白蛋白溶液、人血浆、兔血清和血浆样品溶液中游离氯氮平的浓度．根据前沿峰的峰高直接测定了样品溶液中的游离氯氮平浓度,并与传统超滤法进行了比较．通过考察施加的电压和运行缓冲液的组成对氯氮平电泳峰平台形成的影响确定了最优分离条件．讨论了氯氮平蛋白结合作用的选择性．     

酮洛芬与蛋白结合作用的高效液相色谱-迎头分析法研究及其与高效毛细管电泳-迎头分析法的比较

采用高效液相色谱-迎头分析法(HPLC-FA),以67 mmol/L (pH 7.4, I=0.17 mol/L) 的等渗磷酸盐缓冲液为流动相,Pinkerton GFF　Ⅱ-S5-80内表面反相柱(150 mm×4.6 mm i.d., 5 μm)为固定相,254 nm下检测,研究了酮洛芬与人血清白蛋白(HSA)的结合作用,通过非线性回归参数估算求得酮洛芬与HSA的结合参数。与高效毛细管电泳-迎头分析法(HPCE-FA)相比,HPLC-FA法具有高灵敏度的优势,但进样量较大,分析时间较长。HPLC-F     

HPLC-UV assay for monitoring total and unbound mycophenolic acid concentrations in children

A simple, accurate and sensitive HPLC method was developed for measuring total and unbound mycophenolic acid (MPA) in human plasma. Total MPA was extracted by protein precipitation and ultrafiltration was used to assess unbound MPA concentrations. The supernatant (20 microL) or ultrafiltrate (100 microL) was injected onto a C(18) HPLC column with a mobile phase of 0.05 m sodium phosphate buffer (pH 2.31)-acetonitrile (55:45, v/v for total MPA; 50:50 for unbound MPA) with UV detection at 254 nm. The extraction recovery was over 93% and reproducible. The assay was linear over the concentration range of 0.07-50 mg/L for total MPA and 4-1500 microg/L for unbound MPA. Intra- and inter-day assay reproducibility was less than 10%. Detection limits were 0.04 mg/L and 2 microg/L for total and unbound MPA, respectively. The assay utility was established in samples collected from five paediatric bone marrow transplant recipients who were receiving intravenous doses of mycophenolate mofetil. In these patients MPA concentrations ranged from 0.07 to 7.83 mg/L and unbound drug concentrations ranged from 2.1 to 107.5 microg/L. This method can be effectively applied to MPA pharmacokinetics in paediatric patients.     

碱性药物与人血清白蛋白结合参数的毛细管区带电泳/前沿分析

将毛细管区带电泳／前沿分析技术用于测定碱性药物ｖｅｒａｐａｍｉｌ（ＶＥＲ）和ｐｒｏｐｒａｎｏｌｏｌ（ＰＲＯ）与人血清白蛋白（ＨＳＡ）平衡体系中结合参数的研究。通过压力进样将药物白蛋白混合液引入石英毛细管电泳柱（３２ｃｍ×５０μｍｉ．ｄ．,聚丙烯酰胺涂渍柱）,在ｐＨ值为７．４、离子强度为０．１７的磷酸缓冲液及运行电压为１０ｋＶ的条件下,未结合的碱性药物的浓度可以通过电泳平台峰的高度定量,并且具有良好的线性关系（相关系数ｒ＝０．９９９）。     

Simultaneous determination of the free and total carbamazepine concentrations in human plasma by high-performance frontal analysis using an internal-surface reversed-phase silica support

High-performance frontal analysis (HPFA) was applied to simultaneous determinations of the free and total carbamazepine (CBZ) concentrations in human plasma. When 1.5ml of human plasma containing CBZ at a clinical therapeutic level (free fraction, about 30%) was directly injected into an internal-surface reversed-phase silica column, the CBZ was separated from the plasma blank and was eluted as a zonal peak with a plateau height corresponding to the free CBZ concentration in protein binding equilibrium. Slow and continuous introduction of the plasma sample and the use of titanium filters permitted us to inject the sample repeatedly while avoiding a rapid increase in column pressure. The free and total CBZ concentrations were determined simultaneously from the peak height at the plateau region and the area of the CBZ peak, respectively. The within-run and day-to-day reproducibilities were satisfactory (C.V. less than or equal to 1.63%, n = 5).     

Single run measurements of drug-protein binding by high-performance frontal analysis capillary electrophoresis and mass spectrometry

A novel drug-protein binding measurement method based on high-performance frontal analysis and capillary electrophoresis (HPFA/CE) is presented. A single run measurement approach is proposed to circumvent utilization of a calibration curve that is often performed with HPFA. A sensitive mass spectrometer is applied as a detector enabling the measurement of in vitro protein binding at lower drug concentrations. Unbound free fraction and binding constants can be determined by a single run measurement by consecutive injections of an internal drug standard, a buffer plug and a drug-protein mixture. Effects of injection volumes on peak height and plateau profile were investigated in two different separation systems, non-volatile buffer and volatile buffer, with UV and mass spectrometry detection, respectively. A simplified one-to-one binding model is employed to evaluate the proposed method by using both single and multiple drug concentrations to measure the unbound free fraction and calculate the binding constants of some selected compounds. The method is suitable for rapid and direct screening of the binding of a drug to a specific protein or drug-plasma protein binding.     

Capillary electrophoresis study of human serum albumin binding to basic drugs

Summary The applicability of capillary electrophoresis/frontal analysis (CE/FA) for determining the binding constants of the drugs propranolol (PRO) and verapamil (VER) to human serum albumin (HSA) was investigated. After direct hydrodynamic injection of a drug-HAS mixture solution into a coated capillary (32 cm × 50 μm i.d.), the basic drug was eluted as a zonal peak with a plateau region under condition of phosphate buffer (pH 7.4; ionic strength 0.17) at 12 kV positive running voltage. The unbound drug concentrations measured from the plateau peak heights had good correlation coefficients,r>0.999. Employing the Scatchard plot, the Klotz plot and nonlinear regression, the drug protein binding parameters, the binding constant and the number of binding sites on one protein molecule, were obtained. The binding constant obtained was compared to a reported equilibrium dialysis result and they are basically in good agreement.