高通量自动化免疫磁珠净化-超高效液相色谱法检测饲料中4种黄曲霉毒素

黄曲霉毒素(AFT)是一种毒性极强的剧毒物质,具有致癌性。饲料原料及产品在生产、运输和储藏等过程存在被黄曲霉毒素污染的风险。该文建立了高通量自动化免疫磁珠净化-超高效液相色谱法测定饲料中4种黄曲霉毒素(黄曲霉毒素B₁(AFB₁)、黄曲霉毒素B₂(AFB₂)、黄曲霉毒素G₁(AFG₁)和黄曲霉毒素G₂(AFG₂))的分析方法。饲料样品用乙腈-水(70∶30, v/v)提取,经免疫磁珠自动净化后,使用超高效液相色谱进行分析测试。对磁珠与抗体的偶联比例、免疫磁珠与黄曲霉毒素的反应时间、样品提取液和稀释液等关键实验条件进行了优化,考察了不同饲料样品的净化效果。在优化条件下,豆粕、玉米干酒糟及其可溶物、猪饲料和鸡饲料等4种常见饲料样品在3个水平(5、20和40μg/kg,以AFB₁计)下的加标回收率在91.1%～119.4%之间,相对标准偏差小于6.9%;日间精密度为4.5%～7.5%,该方法具有良好...     

基于MXene的黄曲霉素电化学适体传感器的构建

本文利用黄曲霉素(AFB₁)与AFB₁适体的特异性识别来测定AFB₁的含量。采用MXene材料中的Ti₃C₂纳米材料掺杂金纳米颗粒作为传感基底,以负载金纳米颗粒的金属有机框架材料Au NPs@UiO-66-NH₂为信号探针,利用杂交作用将标记有Au NPs@UiO-66-NH₂的AFB₁适体链结合到DNA₁上。采用差分脉冲伏安法(DPV),在Tris-HCl缓冲溶液中测定Au NPs@UiO-66-NH₂复合材料的DPV响应电流,构建了signal-off型的电化学适体传感器。传感器对AFB₁的线性响应范围为0.1～110 ng·mL^-1,检出限为0.0331 ng·mL^-1,线性方程为△I=0.5487x+0.9530,实现了对目标物的定量检测。     

原位磁固相萃取/液相色谱-串联质谱检测人血清中25-羟基维生素D北大核心CSCD

本研究提出一种原位磁固相萃取法并联合液相色谱-串联质谱(LC-MS/MS)检测人血清中25-羟基维生素D 2[25(OH)VD 2]和25-羟基维生素D 3[25(OH)VD 3]。研究利用原位磁固相萃取法高效提取人血清样本中25(OH)VD,联合LC-MS/MS测定人血清中25(OH)VD 2和25(OH)VD 3,并考察了方法的线性范围、定量下限、基质效应、精密度与准确度。实验结果表明,原位磁固相萃取法联合LC-MS/MS检测人血清25(OH)VD 2和25(OH)VD 3的检测限均为0.5 ng/mL,线性范围均为1~100 ng/mL,回收率范围为98%~103%,日内精密度与日间精密度均在7%以内。因此,原位磁固相萃取法可有效净化复杂生物样本,联合LC-MS/MS可便捷、快速、准确检测临床上人血清样本中25(OH)VD,有望应用于更多复杂样本基质下痕量化合物的检测场景。     

液相色谱-串联质谱法(LC-MS/MS)测定氢氯噻嗪中三种氯苯胺含量

建立液相色谱-串联质谱法(LC-MS/MS)测定氢氯噻嗪中三种氯苯胺的含量,色谱柱选用(CHIRALCEL??OJ-RH,150 mm×4.6 mm,5μm),离子源采用大气压化学电离源(APCI),使用正离子扫描模式;检测模式为选择反应监测(SRM)。结果显示,邻氯苯胺、间氯苯胺和对氯苯胺分别在0.76 ng·mL^-1～30.55 ng·mL^-1、0.76 ng·mL^-1～30.26 ng·mL^-1和0.76 ng·mL^-1～30.44 ng·mL^-1范围内线性良好,定量限均为0.76 ng·mL^-1,检测限均为0.25 ng·mL^-1;平均加标回收率分别为94.02%、93.27%和90.09%,RSD分别为2.69%、3.84%、3.19%,且稳定性良好。样品检测结果显示6批均未检出三种杂质,建立的分析方法重复性好、专属性强、灵敏度高,适用于氢氯噻嗪中三种氯苯胺的检测。     

液相色谱-串联质谱分析组织中基因组脱氧核糖核酸羟甲基胞嘧啶水平

5-羟甲基胞嘧啶通过阻止脱氧核糖核酸(DNA)甲基化转移酶1(DMNT1)甲基化胞嘧啶来影响DNA甲基化的程度。本文建立了液相色谱-串联质谱(LC-MS/MS)测定组织中全基因组5-羟甲基胞嘧啶水平的方法。采用苯酚-氯仿提取组织DNA,提取的DNA用88%甲酸在140 ℃下裂解,DNA裂解液加入同位素胞嘧啶作内标,经N2吹干后,加乙腈-水(9:1, v/v)溶解,用LC-MS/MS检测5-羟甲基胞嘧啶的含量,并计算全基因组中5-羟甲基胞嘧啶的水平。结果表明,5-羟甲基胞嘧啶的线性范围为0.1～30 ng/mL,相关系数为0.9969,检出限(信噪比为3计)和定量限(信噪比为10计)分别为0.057 ng/mL和0.090 ng/mL;日内相对标准偏差和日间相对标准偏差分别为5.13%和6.24%;加标回收率为90.24%～97.53%。用该方法检测了大鼠大脑组织DNA羟甲基化水平,平均结果为0.66%。该方法简便,重现性好,灵敏度较高,能满足全基因组5-羟甲基胞嘧啶定量检测的要求。     

基于乙酰胆碱酯酶构建pH响应生物传感器用于Hg(Ⅱ)检测

以磁纳米颗粒和金纳米颗粒为载体,以核酸适配体和Hg~(2+)为生物识别单元,构建一种乙酰胆碱酯酶(AChE)联Hg~(2+)生物传感平台。分别对磁纳米颗粒进行适配体功能化,金纳米颗粒进行AChE修饰和适配体的功能化,通过目标物Hg~(2+)驱动富含碱基T的适配体形成T-Hg~(2+)-T结构,形成金-磁组装体,通过磁分离调控检测体系中AChE的浓度,AChE催化底物乙酰胆碱(ACh)水解引起反应体系的pH变化,从而实现目标物Hg~(2+)的定量检测。结果表明,方法检测范围为0.1～10 ng/mL,检出限为0.05 ng/mL。将该方法应用于自来水样品中Hg~(2+)的检测,当加标水平为0.1,1,10 ng/mL时,回收率为102.2%～113.2%,相对标准偏差为3.5%～4.1%。     

超高效合相色谱-质谱法对甲卡西酮对映异构体的手性分离和定量检测

建立了超高效合相色谱-质谱法(UPC2-MS)对甲卡西酮(MC)对映异构体进行手性分离和定量检测。使用Acquity UPC² Trefoil CEL2 (2.5μm, 3.0 mm×150 mm)手性色谱柱,以超临界流体CO₂为主要流动相,含10 mmol/L甲酸铵和0.1%甲酸的异丙醇为改性剂进行梯度洗脱,可以在13 min内实现2个对映异构体的基线分离。在三重四极杆质谱多反应监测(MRM)模式下,2个对映异构体的检出限为0.5 ng/mL,定量限为1.0 ng/mL,在1～100 ng/mL质量浓度范围内线性关系良好,线性相关系数(R²)≥0.999, 10种常见毒品和药品对检测均无干扰。对实际缴获毒品的检测结果表明：直接作为毒品销售的MC主要为外消旋体,而非法制造麻黄碱的地下窝点缴获的MC以S构型为主。     

基于上转换荧光纳米粒子和金纳米粒子间荧光共振能量转移的高灵敏赭曲霉毒素A检测方法研究

制备了水溶性的上转换荧光纳米材料,在其表面修饰赭曲霉毒素A(OTA)适配体作为能量供体探针;在金纳米粒子表面修饰OTA适配体互补链作为能量受体探针,构建了OTA适配体传感器。在最优条件下,OTA的检测范围为0.001~10 ng/mL,检出限可达0.001 ng/mL。将其应用于啤酒样品中OTA的检测,当加标水平为0.01、0.1、1.0 ng/mL时,回收率为100%~119%,相对标准偏差为4.3%~4.9%,表明该方法可用于实际样品检测。该方法具有灵敏度高、特异性好、操作简单、成本较低等优点。     

基于Fe(Ⅲ)-2-氨基对苯二甲酸金属有机框架的免标记氯霉素电化学传感器的构建及应用

快速、简便的氯霉素(CAP)传感检测技术在食品安全和环境监测等领域具有良好的应用前景。本研究以FeCl₃·6H₂O和2-氨基对苯二甲酸(2-ATPA)为原料，采用水热合成法成功制备了金属有机框架(MOF)材料NH₂-MIL-88(Fe)，并利用2-ATPA配体上的氨基，将其共价固定在羧基化的玻碳电极表面；进一步利用磷酸基团(-PO₄^3–)与铁离子(Fe(Ⅲ))之间的强配位作用，将5′-PO₄^3–修饰的CAP核酸适配体(C-Apt)直接自组装到NH₂-MIL-88(Fe)修饰电极表面，无需额外交联剂和预活化过程，构建了一种新型C-Apt电化学传感界面。电化学实验结果表明，基于NH₂-MIL-88(Fe)的类过氧化物酶活性，NH₂-MIL-88(Fe)修饰电极对H₂O₂/3,3′,5,5′-四甲基联苯胺(TMB)表现出明显的电催化...     

基于CdSe@CdS/壳聚糖/gC3N4复合物的卡那霉素电化学发光适配体传感器

利用核壳型的CdSe@CdS量子点作为发光物质,并用壳聚糖(CS)、类石墨烯氮化碳(gC₃N₄)与CdSe@CdS量子点合成了CdSe@CdS/CS/gC₃N₄复合物,将该复合物修饰至玻碳电极(GCE)表面,将适配体(Apt)的互补DNA链(cDNA)通过化学反应连接到量子点上,Apt与cDNA发生杂交反应而被修饰至电极表面。将辣根过氧化物酶(HRP)固定到该修饰电极表面,构建了检测卡那霉素(Kana)的电化学发光(ECL)适配体传感器。通过生物催化沉淀(BCP)方法实现Kana的检测,溶液中无Kana时,在H₂O₂的存在下,修饰在电极上的HRP可以催化氧化4-氯-1-萘酚(4-CN),在电极表面产生不导电的苯并-4-氯己二烯酮沉淀,导致电化学发光信号明显降低。溶液中存在Kana时,Kana会与Apt特异性结合,部分dsDNA解旋,导致部分HRP从电极表面脱落,BCP反应减弱,导致ECL信号增强,实现目标物质的特异性检测。计算适配体传感器在Kana溶液中的...     

基于SiO_(2)@Fe_(3)O_(4)的磁性纳米材料分离富集谷物中痕量黄曲霉毒素B_(1)北大核心CSCD

将SiO_(2)包覆的Fe_(3)O_(4)磁性纳米材料(SiO_(2)@Fe_(3)O_(4))表面偶联识别黄曲霉毒素B_(1)(AFB_(1))的抗体(Ab),用于特异性分离富集谷物中的AFB_(1),进而与高效液相色谱-串联质谱法(HPLC-MS/MS)结合,用于大米、玉米和小麦中AFB_(1)的高效准确检测。采用微波辅助水热合成法制备得到Fe_(3)O_(4)磁性纳米颗粒,并用100μL正硅酸乙酯(TEOS)对其进行SiO_(2)的包覆,得到SiO_(2)@Fe_(3)O_(4)磁性纳米材料,随后进行抗体的偶联得到Ab-SiO_(2)@Fe_(3)O_(4);以pH=7.4的磷酸盐缓冲液(PBS)作为富集缓冲液,加入8 mg Ab-SiO_(2)@Fe_(3)O_(4),在37℃下反应10 min进行AFB_(1)的分离富集,随后采用甘氨酸-盐酸(Gly-HCl)缓冲液对Ab-SiO_(2)@Fe_(3)O_(4)分离富集的AFB_(1)进行洗涤,将洗涤液氮吹后复溶,采用高效液相色谱-串联质谱法检测。在最佳条件下,方法检测AFB_(1)的线性范围为2~50μg/L,相关系数(R^(2))>0.99,检出限为0.04μg/kg,定量限为0.13μg/kg。在4个不同加标水平下,AFB_(1)在3种谷物基质中的加标回收率为76.21%~92.85%,RSD≤5.29%。大米、玉米和小麦等实际谷物样品中AFB_(1)的测定结果显示,在1个小麦样品和2个玉米样品中检出AFB1,其含量分别为0.38、0.13和0.47μg/kg,其他样品中并未发现AFB_(1)。方法将磁性纳米材料与HPLC-MS/MS相结合,实现了AFB_(1)的高效分离富集,富集材料成本低廉,储存性能好,在30 min内即可完成前处理过程,可在较短的时间内实现大批量样品的实际分析,在谷物中真菌毒素的检测方面具有良好的应用前景。     

免疫磁珠富集净化-超高效液相色谱法同时测定陈皮中4种黄曲霉毒素

将ProtElut NHS(N-羟基丁二酰亚胺)偶联磁珠与抗黄曲霉毒素总量单克隆抗体偶联得到黄曲霉毒素总量免疫磁珠,其具有较好的分散性,良好的磁性能和特异的选择性。本文建立了陈皮中4种黄曲霉毒素的免疫磁珠富集净化,超高效液相色谱(UPLC)检测方法。样品经甲醇-PBS缓冲溶液(2:8, v/v)提取后用免疫磁珠富集净化,1 mL甲醇洗脱;经ACQUITY UPLC HSS T3 C₁₈色谱柱(100 mm×2.1 mm, 1.8 μm)分离,以水和甲醇为流动相梯度洗脱,采用汞/氙灯荧光检测器测定。实验结果表明,4种黄曲霉毒素在各自的线性范围内峰面积与其质量浓度线性关系良好,相关系数(r²)大于0.999;检出限(信噪比为3)为0.013~0.038 μg/kg,定量限(信噪比为10)为0.044~1.2 μg/kg;平均回收率为63.9%~115.0%,相对标准偏差为0.4%~14.2%,均符合痕量分析的要求。该方法简单快速、准确可靠,可用于陈皮中4种黄曲霉毒素的测定。     

Electrochemical immunosensor for determination of aflatoxin B1 in barley

This paper reports the assembly of a disposable electrochemical immunosensor based on the indirect competitive enzyme linked immunosorbent assay (ELISA), for simple and fast measurement of aflatoxin B₁ (AFB₁) in barley using differential pulse voltammetry (DPV). The immunosensor strip was assembled immobilising the biological component (i.e. the AFB₁ conjugated to bovine serum albumin, incubation the sample (or standard) with the monoclonal antibody anti-AFB₁ (MAb). A spectrophotometric ELISA was used in a preliminary phase of development, prior to transferring the assay to the SPEs.

Results showed a detection limit of 20 and 30 pg/mL for the spectrophotometric ELISA and the electrochemical immunosensor, respectively.

The extraction efficiency and the matrix effect have been evaluated by spiking blank barley with AFB₁ before and after the sample treatment. After treatment, samples were analysed using a 1:10 (v/v) dilution in PBS (phosphate-buffered saline, pH 7.4) in order to minimise the matrix effect. Good recoveries were obtained, which demonstrated the suitability of the proposed method for routine screening of AFB₁ in barley.     

SiW11掺杂二氧化硅纳米纤维(SiW11/SiO2)的制备及对拟南芥叶中多胺的萃取分析

采用静电纺丝技术制备了SiW₁₁掺杂的二氧化硅纳米纤维(SiW₁₁/SiO₂)材料, 其中掺杂的SiW₁₁质量占纤维质量的7.83%, 制备的SiW₁₁/SiO₂材料尺寸均一, 在考察的pH范围内带负电, 与未掺杂SiW₁₁的二氧化硅纳米纤维相比, SiW₁₁/SiO₂材料表现出强阳离子交换作用, 能有效萃取尸胺和腐胺. 在最优条件下, 建立了注射器分散固相萃取(In syringe dSPE)-超高效液相色谱-串联质谱联用(UHPLC-MS/MS)检测拟南芥样品中多胺的方法. 结果表明, 尸胺和腐胺分别在10~1000和20~1000 ng/mL浓度范围内具有良好的线性关系(R²≥0.9950), 检出限和定量限分别为0.5~0.9和1.6~3.0 ng/mL. 将该方法应用于拟南芥样品中尸胺和腐胺的检测, 加标回收率在87.5%~111.3%之间, 相对标准偏差RSD<5.0%. 建立的SiW₁₁/SiO₂制备方法解决了多金属氧酸盐(POM)在修饰改性过程中存在的制备繁琐、 固载量少的问题, 拓宽了POM在分离领域中的应用.     

Metal-organic framework derived magnetic nanoporous carbon as an adsorbent for the magnetic solid-phase extraction of chlorophenols from mushroom sample

In this work, a metal-organic framework derived nanoporous carbon(MOF-5-C) was fabricated and modified with Fe_3O_4 magnetic nanoparticles. The resulting magnetic MOF-5-derived porous carbon(Fe_3O_4@MOF-5-C) was then used for the magnetic solid-phase extraction of chlorophenols(CPs) from mushroom samples prior to high performance liquid chromatography–ultraviolet detection. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and N_2 adsorption were used to characterize the adsorbent. After experimental optimization, the amount of the adsorbent was chosen as 8.0 mg, extraction time as 10 min, sample volume as 50 m L, desorption solvent as 0.4 m L(0.2 mL×2)of alkaline methanol, and sample p H as 6. Under the above optimized conditions, good linearity for the analytes was obtained in the range of 0.8–100.0 ng g~(-1)with the correlation coefficients between0.9923 and 0.9963. The limits of detection(S/N = 3) were in the range of 0.25–0.30 ng g~(-1), and the relative standard deviations were below 6.8%. The result showed that the Fe3O4@MOF-5-C has an excellent adsorption capacity for the analytes.     

Method validation for the analysis of 169 pesticides in soya grain, without clean up, by liquid chromatography-tandem mass spectrometry using positive and negative electrospray ionization

Part of a comprehensive study on the comparison of different extraction methods, GC-MS(/MS) and LC-MS/MS detection methods and modes, for the analysis of soya samples is described in this paper. The validation of an acetone-based extraction method for analysis of 169 pesticides in soya, using LC-MS/MS positive and negative electrospray ionisation (ESI) mode, is reported. Samples (5 g) were soaked with 10 g water and subsequently extracted with 100 mL of a mixture of acetone, dichloromethane and light petroleum (1:1:1), in the presence of 15 g anhydrous sodium sulphate. After centrifugation, aliquots of the extract were evaporated and reconstituted in 1.0 mL of methanol, before direct injection of the final extract (corresponding with 0.05 g soya mL(-1)) into the LC-MS/MS system. Linearity, r(2) of calibration curves, instrument limit of detection/quantitation (LOD/LOQ) and matrix effect were evaluated, based on seven concentrations measured in 6-fold. Good linearity (at least r(2)> or =0.99) of the calibration curves was obtained over the range from 0.1 or 0.25 to 10.0 ng mL(-1), corresponding with pesticide concentrations in soya bean extract of 2 or 5-200 microg kg(-1). Instrument LOD values generally were 0.1 or 0.25 ng mL(-1). Matrix effects were negligible for approximately 90% of the pesticides. The accuracy, precision and method LOQ were determined via recovery experiments, spiking soya at 10, 50, 100 microg kg(-1), six replicates per level. In both ESI modes, method LOQ values were mostly 10 or 50 microg kg(-1) and more than 70% of pesticides analysed by each mode met the acceptability criteria of recovery (70-120%) and RSD (< or =20%), at one or more of the three levels studied. A fast, easy and efficient method with acceptable performance was achieved for a difficult matrix as soya, without cleanup.     

Development of a rapid and sensitivity magnetic chemiluminescence immunoassay for DNA methyltransferase 1 in human serum

DNA methyltransferase 1(DNMT1) is a useful biomarker for lung cancer in early clinical diagnosis. A rapid magnetic chemiluminescence immunoassay(MCLIA) for DNMT1 in human serum has been developed.Horseradish peroxidase(HRP)-second-Ab was used to labeled polyclonal antibodies of anti-DNMT1. DNMT1 in sample integrates with specific immunomagnetic beads and can constitute a supersandwiched immunoreaction. In magnetic field, nonspecific materials can be separated. After luminescent substrate luminol-H_2O_2-BIP was added, the relative light unit(RLU) of HRP was detected and was discovered to be directly proportional to the content of DNMT1 in sample. The correlative variables involved in the MCLIA value were optimized and the methodological evaluation was carried out. After optimization, in the range of0.5–128 ng/mL, the linear regression equation was y = 0.5014 x + 1.769(x was logCDNMT1, y was relative luminescence units(RLU)/RLU0), and the limit of detection was 0.01 ng/mL. The RSD of intra-and interassays were 15.8%–16.9% and 14.3%–18.1%, respectively. The recovery was from 70.0% to 106.2%.Furthermore, paralleled with purchasable enzyme-linked immunosorbent assay(ELISA) kits, MCLEIA had lower detection limit, wider linear range and shorter detection time. Therefore, the MCLEIA established in this study could be used for the sensitive detection of DNMT1 in serum sample.     

Stable Isotope Dilution Analysis of Gibberellin Residues in Tomato Paste by Liquid Chromatography-Tandem Mass Spectrometry

An accurate and sensitive method for the simultaneous determination of gibberellic acid(GA₃), gibberellin A₄(GA₄) and gibberellin A₇(GA₇) residues in tomato paste was developed by coupling solid phase extraction to high performance liquid chromatography-tandem mass spectrometry(LC-MS/MS) with electrospray ionization based stable isotope dilution analysis(SIDA). The isotope labeled internal standard can compensate for the losses during the extraction and cleanup steps and for discrimination due to ion suppression. After extraction from methanol, hydrophile lipophilic balance(HLB) solid phase extraction(SPE) column was tested for the capacity of the cleanup of the tomato paste in compared with C₁₈ SPE column which is the common way to the detection of GAs, and the former gained better result. Spiked experiments were performed in the non-contaminated tomato pastes and the recoveries of GA₃, GA₄ and GA₇ were 42.6%―75.0% in external standard method(ESM) and 91.1%―103.8% in internal standard method(ISM) respectively. The validities of this method were investigated and good analytical performance for the three GAs was obtained, including low limits of method detection(2 ng/g for GA₃ and GA₄, 0.3 ng/g for GA₇), excellent linear dynamic ranges(5―500 ng/g for GA₃ and GA₄, 1―100 ng/g for GA₇) and good relative standard deviation ranges(4.8%―9.4% for the intra-day test and 3.5%―11.9% for the inter-day test).     

液相色谱-串联质谱法检测血清中15种甾体激素的动态变化

建立了用液相色谱-串联质谱检测血清中15种甾体激素的方法。在血清样品中加入含内标的乙腈沉淀蛋白质后,用100 mmol/L盐酸羟胺衍生,经Agilent-C18柱(50 mm×3.0 mm,2.7μm)分离,内标法定量。质谱分析采用电喷雾电离(ESI)正离子扫描,多反应监测(MRM)模式检测。数据显示,13种激素在0.05~20 ng/mL范围内线性关系良好(相关系数(R2)不小于0.995 6),检出限不大于1 ng/mL;皮质醇及脱氢表雄酮硫酸酯在50~2 000ng/mL范围内线性关系良好(R2不小于0.997 9),检出限不大于0.5 ng/mL。将该方法应用于女性月经周期激素变化规律的研究,结果表明,15种甾体激素在一个完整的月经周期内有不同特征的动态变化,其中雄激素在滤泡期的后期达到最高值,孕(雌)激素在黄体期达到最高值,而皮质激素则波动不明显。该方法灵敏度高、重复性好,为临床诊疗提供了参考。     

Quantitative detection of salmeterol after inhalation in equine urine by liquid chromatography/tandem mass spectrometry

A sensitive, accurate and precise liquid chromatography/tandem mass spectrometry (LC/MS(2)) method was developed for the quantification of salmeterol in the urine of horses. The method consists of a liquid-liquid extraction with tert-butylmethyl ether and isopropanol at pH 12 after enzymatic hydrolysis. The extracts are analysed using an LC/MS system equipped with an electrospray ionisation (ESI) probe. Method validation showed excellent linearity, specificity, accuracy, precision and intra-laboratory repeatability and reproducibility. The limit of quantitative detection was 0.25 ng/mL and the limit of detection was 0.125 ng/mL. The excretion profile was determined after administration of 500 microg salmeterol (Serevent) to four standard-bred mares via a metered dose inhaler (MDI) with an Equinehaler adapter. Salmeterol was detected from 1 h until 12 h post-administration. Maximum urinary concentrations varied between 2.3 and 14.9 ng/mL.