Potential of atmospheric pressure chemical ionization source in gas chromatography tandem mass spectrometry for the screening of urinary exogenous androgenic anabolic steroids

The atmospheric pressure chemical ionization (APCI) source for gas chromatography-mass spectrometry analysis has been evaluated for the screening of 16 exogenous androgenic anabolic steroids (AAS) in urine. The sample treatment is based on the strategy currently applied in doping control laboratories i.e. enzymatic hydrolysis, liquid–liquid extraction (LLE) and derivatization to form the trimethylsilyl ether-trimethylsilyl enol ether (TMS) derivatives. These TMS derivatives are then analyzed by gas chromatography tandem mass spectrometry using a triple quadrupole instrument (GC-QqQ MS/MS) under selected reaction monitoring (SRM) mode. The APCI promotes soft ionization with very little fragmentation resulting, in most cases, in abundant [M + H]⁺ or [M + H-2TMSOH]⁺ ions, which can be chosen as precursor ions for the SRM transitions, improving in this way the selectivity and sensitivity of the method. Specificity of the transitions is also of great relevance, as the presence of endogenous compounds can affect the measurements when using the most abundant ions. The method has been qualitatively validated by spiking six different urine samples at two concentration levels each. Precision was generally satisfactory with RSD values below 25 and 15% at the low and high concentration level, respectively. Most the limits of detection (LOD) were below 0.5 ng mL⁻¹. Validation results were compared with the commonly used method based on the electron ionization (EI) source. EI analysis was found to be slightly more repeatable whereas lower LODs were found for APCI. In addition, the applicability of the developed method has been tested in samples collected after the administration of 4-chloromethandienone. The highest sensitivity of the APCI method for this compound, allowed to increase the period in which its administration can be detected.     

离子色谱-串联质谱法检测茶叶中的高氯酸盐

建立了离子色谱-串联质谱检测茶叶中高氯酸盐的分析方法。选用高容量、强亲水性的IonPac AS20阴离子交换柱（2 mm）进行分离,以淋洗液自动发生器在线产生的70 mmol/L氢氧化钾为淋洗液等浓度淋洗,TSQ Quantiva三重四极杆质谱仪作检测器,采用电喷雾电离源负离子（ESI^-）模式、多反应监测（MRM）模式进行分析,内标法定量。结果表明,高氯酸盐在0.02~10.0 μg/L范围内线性关系良好,相关系数（r）为0.9991,定量限为2 μg/kg。运用该方法测定5种茶叶中的高氯酸盐,加标回收率为87.3%~112.2%。该方法具有操作简单、专属性强、灵敏度高等优点,可满足茶叶中高氯酸盐的检测要求。     

超高效液相色谱-电喷雾电离串联质谱联用法检测茶叶中阿维菌素类药物残留

建立了采用超高效液相色谱-电喷雾电离串联质谱同时检测茶叶中爱比菌素、甲胺基阿维菌素、乙酰胺基阿维菌素、伊维菌素、多拉菌素、莫西丁克残留的方法。试样经饱和氯化钠溶液浸润后,用乙腈提取,C18固相萃取小柱净化,超高效液相色谱-电喷雾串联质谱法(UPLC/ESI-MS/MS)测定。对流动相、监测离子、校正曲线等进行了优化和探讨。6种分析物在2.0～50 μg/L范围内线性关系良好,相关系数均大于0.9920。莫西丁克在5,10,20 μg/kg,其余分析物在2,5,10 μg/kg加标水平的平均回收率为61.7%～85.4%,相对标准偏差为9.37%～17.19%。该方法可靠、稳定,可满足茶叶中阿维菌素类药物残留检测与确证的需要。     

Fast analysis of 19 anabolic steroids in bovine tissues by high performance liquid chromatography with tandem mass spectrometry

For the detection of 19 steroid hormones in bovine muscle, a fast and sensitive liquid chromatography with electrospray ionization tandem mass spectrometry method was developed using both positive and negative ionization mode. Chromatographic separation on Poroshell 120‐EC C18 column was achieved in less than 10 min using isocratic elution of mobile phase of acetonitrile/methanol/water. The compounds were extracted from muscle tissue using ethyl acetate and quick, easy, cheap, effective, rugged, and safe technique. The purification of the obtained extract was performed by dispersive solid‐phase extraction with sorbents C18, primary secondary amine and magnesium sulphate. The method was validated in accordance with the Commission Decision 2002/657/EC. For all steroids tested good recoveries were obtained (from 51.2 to 121.4%) in the concentration range from decision limits until 5 µg/kg. The values of decision limits and the detection capabilities for individual compounds were in the range 0.10–0.48 and 0.17–0.95 µg/kg, respectively. The method was characterized by satisfactory linearity for most compounds (correlation coefficients  > 0.99) and the reproducibility was lower than 35%. The elaborated procedure has met the criteria for confirmatory methods and is currently used in the official control of hormones.     

混合型离子交换液相色谱-串联质谱法检测鸡蛋中10种氨基糖苷类药物残留

该研究系统地优化了样品前处理过程及仪器分析中影响氨基糖苷残留分析准确度与灵敏度的各主要因素,建立了鸡蛋中10种氨基糖苷类药物(链霉素、双氢链霉素、潮霉素B、卡那霉素、阿米卡星、妥布霉素、安普霉素、大观霉素、新霉素、庆大霉素)残留量的混合型离子交换液相色谱-串联质谱分析方法。样品经10 mmol/L乙酸铵缓冲溶液(含0.4 mmol/L EDTA和50 g/L三氯乙酸)超声提取,调节pH至6~7后,经PRiME HLB固相萃取柱富集净化,采用SIELC Obelisc R色谱柱分离,以乙腈和1.0%(v/v)甲酸水溶液(含1 mmol/L甲酸铵)为流动相进行梯度洗脱,在正离子、多反应监测模式下经串联质谱仪测定,外标法定量。该方法在5~200 μg/L质量浓度范围内线性关系良好,相关系数(r²)均大于0.99;方法的检出限(LOD, S/N≥3)为2~5 μg/kg,定量限(LOQ, S/N≥10)为5~10 μg/kg。在空白鸡蛋中进行LOQ、20 μg/kg、100 μg/kg 3个水平的加标回收实验,方法的平均回收率(n=6)为68.1%~111.3%,相对标准偏差为1.2%~12.3%。利用该方法对市售的20批次鸡蛋样品进行测定,均未检出目标物。本方法简单、灵敏、准确,可实现鸡蛋中10种氨基糖苷类药物残留的批量检测。     

Development and validation of a qualitative screening method for the detection of exogenous anabolic steroids in urine by liquid chromatography-tandem mass spectrometry

A screening method for the urinary detection of 34 exogenous anabolic steroids has been developed. The method involves an enzymatic hydrolysis, liquid-liquid extraction and detection by liquid chromatography-tandem mass spectrometry. The use of some adducts such as [M+NH₄]⁺, [M+CH₃COO]⁻ and [M+H+MeOH]⁺ was necessary in order to detect some analytes at the required level (lower than 10 ng/ml). Two transitions were selected for each analyte. Different concentration factors have been studied in order to increase the sensitivity. A concentration factor of 50 was selected for the screening method although the high ion suppression observed under these conditions can hamper its application as a quantitative method. The method was validated and limits of detection were obtained by spiking ten different blank urine samples at five different concentration levels. Up to 29 analytes were detected in all spiked urines at the required level. Limits of detection between 1 and 10 ng/ml were obtained for most analytes which fulfil current requirements. The applicability of the method was shown by analysing positive samples.     

Determination of anabolic androgenic steroids as imidazole carbamate derivatives in human urine using liquid chromatography–tandem mass spectrometry

Anabolic androgenic steroids are widely abused substances in sports doping. Their detection present limitations regarding the use of soft ion sources such as electrospray or atmospheric pressure chemical ionization by liquid chromatography–tandem mass spectrometry. In the current study, a novel derivatization method was developed for the ionization enhancement of selected anabolic androgenic steroids. The proposed method aims at the introduction of an easily ionizable moiety into the steroid molecule by converting the hydroxyl groups into imidazole carbamates using 1,1′‐carbonyldiimidazole as derivatization reagent. The proposed method was applied to water and urine samples spiked with exogenous anabolic androgenic steroids in various concentration levels. Steroid imidazole carbamate derivatives have shown intensive [M+H]⁺ signals under electrospray ionization and common fragmentation patterns in tandem mass spectrometry mode with [M‐CO₂+H]⁺ and [M‐ΙmCO₂+H]⁺ as major ions with low collision energy. The obtained results showed that the majority of steroids were detectable at concentrations equal or lower to their minimum required performance level according to the World Anti‐Doping Agency technical document. The proposed method is sensitive with a preparation procedure that could be easily applied to the analysis of doping control samples.     

超高压液相色谱-串级质谱分析渔业水中7种激素药物

建立了同时测定渔业养殖水中氢化可的松、泼尼松、醋酸可的松、睾酮、甲睾酮、黄体酮及苯丙酸诺龙等7种激素残留药物的超高压液相色谱-电喷雾电离串联质谱(UPLC-ESI-MS/MS)分析方法.水样用HLB固相萃取柱净化、浓缩后,洗脱液经氮气吹干,残渣用乙腈-水(V∶V=1∶1)溶解,以乙腈和0.1％甲酸水溶液为流动相,经ZORBAXSB-C18色谱柱分离后进行LC-MS/MS多反应检测模式作定性定量分析.方法在0.5～40μggL或1～40μg/L范围具有良好的线性,相关系数大于0.997,检出限(S/N=3)为0.03～0.3μg/L,平均回收率为74.8％～113.0％,相对标准偏差为4.0％～16％.方法适用于渔业养殖水中7种激素的检测分析.     

液相色谱-电喷雾电离质谱法检测尿液中的3种合成类固醇药物

研究建立了合成类固醇药物群勃龙、四氢孕三烯炔酮和孕三烯酮的液相色谱-电喷雾质谱的检测方法。尿样经过β-葡萄糖醛酸酶酶解和叔丁基甲醚提取后,采用Zorbax SB-C18分析柱(150 mm×2.1 mm,5 μm),在流动相为pH 3.5的甲酸铵缓冲液-乙腈的条件下进行梯度洗脱,在正离子模式下检测。考察了不同的质谱条件对这类化合物检测结果的影响。建立了人尿液中合成类固醇药物的液相色谱-电喷雾电离质谱的初筛和确证方法。     

Quantification of testosterone undecanoate in human hair by liquid chromatography–tandem mass spectrometry

Testosterone undecanoate (T‐C11) can be used by athletes in order to improve performance. After oral intake, T‐C11 is rapidly metabolized, hampering discrimination between exogenous and endogenous testosterone. A possible alternative is to detect the intact ester in hair. A method based on liquid chromatography–tandem mass spectrometry was developed for the determination of T‐C11 in hair. The sample procedure consisted of digestion of 200 mg of pulverized hair with tris(2‐carboxyethyl)phosphine hydrochloride and liquid–liquid extraction with n‐pentane. Several parameters such as the mobile phase, the ionization source and the washing step were optimized. The method was validated at different spiked levels obtaining satisfactory values for accuracy (between 92 and 102%) with relative standard deviations lower than 7% and a limit of detection of 0.2 ng/g. The applicability of the method was checked by the analysis of three samples from patients using T‐C11. A peak for the analyte was detected in all samples with concentrations between 0.4 and 8.4 ng/g. Copyright © 2009 John Wiley & Sons, Ltd.     

Screening for exogenous androgen anabolic steroids in human hair by liquid chromatography/orbitrap-high resolution mass spectrometry

A method for the screening of various anabolic steroids and their esters in human hair, based on liquid-chromatography–high resolution mass spectrometry using an Exactive benchtop Orbitrap mass spectrometer, has been set up and validated. This method involved methanolic incubation of 30 mg of hair and analysis of the relevant extract in HPLC using a C18 column. The mass detector, with nominal resolving power of 100,000, operated in full scan mode in APCI under positive ionization mode. Analytes were identified by exact mass, correspondence of isotopic cluster and retention times.     

液相色谱-电喷雾串联质谱法测定禽类产品中克球酚的残留

建立了禽类产品中克球酚残留的液相色谱-电喷雾串联质谱(LC-ESI-MS/MS)检测方法。用甲醇对样品进行提取,提取液用正己烷萃取去油脂,然后用LC-18柱和阴离子交换柱净化,LC-ESI-MS/MS测定。利用基质校正曲线对克球酚准确定量。在2,5,10,20 μg/kg 4个添加水平下,克球酚的平均回收率稳定在55.38%～132.44%之间,日内精密度小于9.54%,日间精密度小于15.27%。在1～40 μg/kg范围内色谱峰面积与克球酚含量呈良好的线性关系,检出限为0.5 μg/kg,定量限为2.0 μg/kg。该方法选择性好,抗干扰能力强,可作为禽类产品中克球酚残留检测的确证方法。     

Quantification of human growth hormone by amino acid composition analysis using isotope dilution liquid-chromatography tandem mass spectrometry

We describe an accurate method for protein quantification based on conventional acid hydrolysis and an isotope dilution-HPLC-mass spectrometry (ID-HPLC-MS) method. Sample purity was confirmed using capillary zone electrophoresis, HPLC and MS. The analyte protein, human growth hormone (hGH), was effectively hydrolyzed by incubation with 8 M hydrochloric acid at 130 °C for 48 h, where at least 1 μM of hGH was treated to avoid possible degradation of released amino acids during hydrolysis. Using a reversed-phase column, the analytes (isoleucine, phenylalanine, proline and valine) were separated within 5 min using an isocratic eluent comprising 10% acetonitrile containing 0.1% trifluoroacetic acid. The detection limit (signal to noise ratio of 3) of amino acids was 5.5-6.2 fmol per injection. The quantification precision (RSD) of amino acids for intra- and inter-day assays was less than 0.98% and 0.39%, respectively. Comparison with other biochemical and instrumental methods revealed substantially higher accuracy and reproducibility of the ID-HPLC-MS/MS method as expected. The optimized hydrolysis and analytical conditions in our study were suitable for accurate quantification of hGH.     

Profiling ABA metabolites in Nicotiana tabacum L. leaves by ultra-performance liquid chromatography-electrospray tandem mass spectrometry

We have developed a simple method for extracting and purifying (+)-abscisic acid (ABA) and eight ABA metabolites - phaseic acid (PA), dihydrophaseic acid (DPA), neophaseic acid (neoPA), ABA-glucose ester (ABAGE), 7′-hydroxy-ABA (7′-OH-ABA), 9′-hydroxy-ABA (9′-OH-ABA), ABAaldehyde, and ABAalcohol - before analysis by a novel technique for these substances, ultra-performance liquid chromatography-electrospray ionisation tandem mass spectrometry (UPLC-ESI-MS/MS). The procedure includes addition of deuterium-labelled standards, extraction with methanol-water-acetic acid (10:89:1, v/v), simple purification by Oasis^® HLB cartridges, rapid chromatographic separation by UPLC, and sensitive, accurate quantification by MS/MS in multiple reaction monitoring modes. The detection limits of the technique ranged between 0.1 and 1 pmol for ABAGE and ABA acids in negative ion mode, and 0.01-0.50 pmol for ABAGE, ABAaldehyde, ABAalcohol and the methylated acids in positive ion mode. The fast liquid chromatographic separation and analysis of ABA and its eight measured derivatives by UPLC-ESI-MS/MS provide rapid, accurate and robust quantification of most of the substances, and the low detection limits allow small amounts of tissue (1-5 mg) to be used in quantitative analysis. To demonstrate the potential of the technique, we isolated ABA and its metabolites from control and water-stressed tobacco leaf tissues then analysed them by UPLC-ESI-MS/MS. Only ABA, PA, DPA, neoPA, and ABAGE were detected in the samples. PA was the most abundant analyte (ca. 1000 pmol/g f.w.) in both the control and water-stressed tissues, followed by ABAGE and DPA, which were both present at levels ca. 5-fold lower. ABA levels were at least 100-fold lower than PA concentrations, but they increased following the water stress treatment, while ABAGE, PA, and DPA levels decreased. Overall, the technique offers substantial improvements over previously described methods, enabling the detailed, direct study of diverse ABA metabolites in small amounts of plant tissue.     

High resolution orbitrap mass spectrometry in comparison with tandem mass spectrometry for confirmation of anabolic steroids in meat

A prominent trend which has been observed in recent years in the analysis of veterinary drugs and growth-promoting agents is the shift from target-oriented procedures, mainly based on liquid chromatography coupled to triple-quadrupole mass spectrometry (LC-QqQ-MS), towards accurate mass full scan MS (such as time of flight (ToF) and Fourier Transform (FT) Orbitrap MS). In this study the applicability of high resolution single-stage-Orbitrap-MS for confirmatory analysis of growth-promoting agents in meat was compared to that of a QqQ-MS. Validation according to CD 2002/657/EC demonstrated that steroid analysis based on Orbitrap MS, operating at a resolution of 50,000 FWHM, is indeed capable to compete with QqQ-MS in terms of selectivity/specificity, while providing excellent linearity (for most compounds >0.99) but somewhat inferior sensitivity. Indeed, CC_αs reached from 0.04–0.88 μg kg⁻¹ for the 34 anabolic steroids upon MS/MS detection, while upon Orbitrap MS detection a range of 0.07–2.50 μg kg⁻¹ was observed. Using QqQ-MS adequate precision was obtained since relative standard deviations, associated with the repeatability and intra-laboratory reproducibility, were below 20%. In the case of Orbitrap MS, for some compounds (i.e. some estrogens) this threshold was exceeded and thus poor precision was observed, which is possibly caused by the lack in sensitivity. Overall, it may be concluded that Orbitrap-MS offers an adequate performance in terms of linearity and precision but lacks in sensitivity for some of the compounds.     

头发中内源性类固醇激素的气相色谱-串联质谱分析

建立了建康人头发中内源性类固醇兴奋剂睾酮、表睾酮、雄酮、苯胆烷醇酮和脱氢表雄酮的气相色谱-串联质谱(GC-MS/MS)分析方法。头发经碱水解后,以乙醚提取,经衍生化后采用GC-MS/MS的多反应监测模式(MRM)分析。方法的线性关系良好,检出限达0.1～0.2 pg/mg;提取回收率为74.6%～104.5%;日内测定的准确度为90.1%～113.7%,日内及日间测定的精密度均小于17.5%。应用所建立的方法测定了80例中国健康人头发中睾酮、表睾酮、雄酮、苯胆烷醇酮和脱氢表雄酮的生理水平,为内源性类固醇兴奋剂滥用的判断提供了方法和基础数据。     

Liquid chromatography–tandem mass spectrometry of porphyrins and porphyrinogens in biological materials: separation and identification of interfering poly(ethylene) glycol by travelling wave ion mobility spectrometry/tandem mass spectrometry

Biological and clinical samples for porphyrin and porphyrinogen analyses by liquid chromatography–tandem mass spectrometry (LC‐MS/MS) are often contaminated with poly(ethylene)glycol (PEG), which complicates the interpretation of mass spectra and characterisation of new porphyrin metabolites. Two contaminating PEG molecules (m/z 833 and m/z 835) were completely separated from uroporphyrin I (m/z 831) by travelling wave ion mobility spectrometry and characterised by tandem mass spectrometry. One of the PEG species (m/z 835) also co‐eluted with uroporphyrinogen I (m/z 837) and was unresolvable by travelling wave ion mobility spectrometry/MS, therefore contaminating the MS/MS mass spectra owing to isotope distribution. These PEG species, with the [M + H]⁺ ions at m/z at 833 and/or m/z 835, co‐eluted with uroporphyrin I and uroporphyrinogen I by LC‐MS/MS and could be wrongly identified as uroporphomethenes. Copyright © 2013 John Wiley & Sons, Ltd.     

气相色谱-三重四极杆串联质谱法测定蔓越橘提取物中的88种农药残留

采用改进的快速,简单、便宜、有效、稳定和可靠的前处理方法(quick,easy,cheap,effective,rugged,safe,即QuEChERS法),结合气相色谱-三重四极杆串联质谱(GC-MS/MS)检测技术,建立了蔓越橘提取物中88种农药残留的分析方法.样品由含1％乙酸的丙酮-正己烷(1∶1,v/v)溶剂...     

超高效液相色谱-电喷雾串联质谱法同时分析鸡肉中7种氟喹诺酮类药物残留

建立了一种同时测定鸡肉中7种氟喹诺酮类药物残留的超高效液相色谱-电喷雾串联质谱确证分析方法(UPLC-ESI-MS/MS)。样品经酸化乙腈提取、正己烷脱脂和HLB固相萃取柱净化,采用ACQUITY UPLCTM BEH C18色谱柱(50 mm×2.1 mm,1.7 μm)分离,以0.1%甲酸水溶液和乙腈作为流动相进行梯度洗脱,电喷雾质谱检测,正离子多反应监测模式进行定性和定量分析。7种药物在5～100 μg/kg范围内线性关系良好,相关系数(r2)均大于0.99;以5,25,50 μg/kg3个浓度水平进行添加回收试验,7种药物的平均回收率在79.2%～108.6%之间,相对标准偏差为4.2%～8.9%,方法的检出限(LOD)为0.2～1.4 μg/kg。方法重现性好、灵敏度高、分析时间短、确证能力强,适用于鸡肉中氟喹诺酮类药物多残留的确证检测。     

Combination of liquid chromatography/tandem mass spectrometry and gas chromatography/mass spectrometry for the detection of 21 anabolic steroid residues in bovine urine

For the detection of anabolic steroid residues in bovine urine, a highly sensitive liquid chromatographic/electrospray ionization tandem mass spectrometric (LC/ESI-MS/MS) method was developed using both positive and negative ionization. For four compounds the ESI mode was not sensitive enough and gas chromatographic/mass spectrometric GC/MS detection was therefore still necessary as a complementary method. The sample clean-up consisted of solid-phase extraction (SPE) on a C(18) column followed by enzymatic hydrolysis and a second solid-phase extraction on a combination of a C(18) and a NH(2) column. After this last SPE clean-up, the eluate was split into two equal aliquots. One aliquot was further purified and after derivatization used for GC/MS analysis. The other aliquot was analyzed with LC/MS/MS in both ESI+ and ESI- modes. The method was validated according to the European Commission Decision 2002/657/EC. Decision limits (CCalpha) were between 0.16 and 1 ng ml(-1) for the compounds detected with the LC/MS/MS method. The developed method is used in routine analysis in our laboratory.