LC/MS/MS法同时测定卷烟主流烟气中4种TSNAs

烟草特有亚硝胺（TSNAs）是存在于、烟草制品和卷烟烟气中的一类有害物质。TSNAs在卷烟烟气中的含量很低,卷烟烟气背景复杂,化学成分达3800多种,卷烟烟气中TSNAs的准确定量难度很大。多年来,TSNAs的测量方法随着分析仪器的进步而不断发展,从薄层色谱到GC、LC,从填充柱到毛细管柱,从FID检测到氮磷检测器检测、热能分析仪检测、质谱检测。     

化学发光法测定卷烟侧流烟气中的氮氧化物

建立了一种用化学发光法测定卷烟侧流烟气中氮氧化物(NOX)的方法。将新鲜的侧流烟气经剑桥滤片过滤、三通分流后用氮氧化物分析仪根据化学发光原理测定卷烟侧流烟气中氮氧化物,用外标法定量。在优化的实验条件下,方法的线性关系良好,一氧化氮(NO)和NOX的相关系数均大于0.999,检测限分别为0.274μmol/支和0.269μmol/支。方法的平均回收率98%~101%,相当标准偏差(RSD)为3.1%~8.8%。该方法适于大批卷烟侧流烟气中氮氧化物的检测。     

LC-MS-MS法测定卷烟侧流烟气中的亚硝胺

采用鱼尾罩和剑桥滤片捕集卷烟侧流烟气中的粒相颗粒物,建立了LC-MS-MS法测定卷烟侧流烟气中4种烟草特有的亚硝胺TSNAs(NNN,NAT,NAB,NNK)。剑桥滤片在醋酸铵水溶液中机械振荡40min后提取萃取液,萃取液经0.22μm滤膜过滤后,直接进LC-MS-MS分析。鱼尾罩壁上的冷凝物用甲醇溶液清洗,洗液通过氮吹浓缩后,采用PCX固相萃取小柱净化进样分析。测定方法的检测限为0.09～0.25ng/mL,线性相关系数均大于0.996,4种TSNAs的回收率均在88.2%～110.2%之间,相对标准偏差RSD均小于7%。方法适合作为卷烟侧流烟气中四种烟草特有亚硝胺(TSNAs)的定量分析方法。     

LC–MS/MS法测定动物性食品中万古霉素残留

建立液相色谱–串联质谱(LC–MS/MS)法检测动物性食品中万古霉素药物残留的方法。用磷酸盐缓冲溶液对动物性食品中的万古霉素进行提取,经HLB固相萃取柱净化,采用电喷雾离子源,以正离子检测方式进行质谱分析。实验结果表明,万古霉素质量浓度在1~500μg/L范围内与色谱峰面积呈良好的线性,相关系数r=0.998。低、中、高3个质量浓度添加水平的回收率为84.8%~118.2%,相对标准偏差为2.2%~7.2%(n=5),检出限为2μg/kg。     

连续流动法测定卷烟侧流烟气中的氨

建立了用稀硫酸溶液吸收—连续流动法测定卷烟测流烟气中氨的方法。通过对吸收条件、精密度、稳定性和加标回收率的全面考察,结果表明:1在2~30μg·m L-1范围内方法具有良好的线性关系(R2=0.9994),,加标回收率在95.74%~107.32%之间,RSD小于3%,方法的检测限为1.45μg/支;2侧流烟气中氨的释放量是主流烟气中的数百倍,且其主要存在于气相部分;3该方法快速准确,重复性好,适合卷烟侧流烟气中氨的大批、快速测定。     

直接萃取-GC/MS法测定卷烟主流烟气中四种芳香胺

采用气相色谱/质谱法直接测定了卷烟主流烟气中的1-氨基萘、 2-氨基萘、 3-氨基联苯和4-氨基联苯等4种芳香胺.该方法直接用CH2Cl2溶剂超声振荡萃取滤片中的芳香胺,超声萃取的同时加入衍生试剂,使萃取和衍生化同步进行,萃取液过硅酸镁柱进行进一步纯化,然后旋转浓缩后进行GC/MS分析.方法的RSD在1.0%～3.7%之间,加标回收率在92.9%～101.1%之间.     

化学电离–气相色谱–串联质谱法测定卷烟侧流烟气中的4种烟草特有亚硝胺

建立了化学电离–气相色谱–串联质谱法测定卷烟侧流烟气中4种烟草特有亚硝胺(TSNAs)的方法。采用吸烟机对卷烟进行抽吸,利用鱼尾罩和剑桥滤片对卷烟侧流烟气进行捕集,用稀盐酸溶液进行鱼尾罩洗涤和剑桥滤片萃取,萃取液经阳离子交换固相萃取柱净化,采用氨水甲醇溶液洗脱,洗脱液经氮气吹干后用二氯甲烷定容至1 mL,过滤膜后检测,利用色谱峰面积内标法定量。4种TSNAs的质量浓度在1～500 ng/mL范围内与各目标物和内标的色谱峰面积比线性关系良好,相关系数均大于0.999 1,检出限为0.16～0.35 ng/mL。加标回收率为80.8%～107.4%,检测结果的相对标准偏差为3.2%～6.8%(n=6)。     

UPLC-MS/MS对卷烟烟气中4种烟草特有亚硝胺的快速测定

建立了卷烟主流烟气中烟草特有亚硝胺的超高效液相色谱-电喷雾串联质谱(UPLC-MS/MS)测定方法。在标准吸烟条件下,采用剑桥滤片收集卷烟烟气粒相物,用醋酸铵缓冲液提取粒相物,经固相萃取净化后,以电喷雾正离子多反应监测方式,实现了烟气中N-亚硝基降烟碱、4-甲基亚硝基吡啶基丁酮、N-亚硝基新烟草碱和N-亚硝基假木贼碱的基线分离和快速测定。4种烟草特有亚硝胺在0~400μg/L范围内具有良好线性,相关系数大于0.998,定量下限为0.08~0.15μg/L,加标回收率为72%~104%,相对标准偏差为3.8%~9.7%。该方法灵敏、快速、准确,适用于卷烟烟气中烟草特有亚硝胺的测定。     

LC-MS/MS法对卷烟主流烟气中8种羰基化合物的测定

卷烟烟气中的挥发性羰基化合物是烟气中的一类重要有害物质,部分已列入烟气44种有害化学成分的"霍夫曼清单"[1-3].从吸烟和健康的角度出发,准确测定烟气中的羰基化合物十分必要.近年来,利用2,4.二硝基苯肼在酸性条件下可与羰基化合物反应生成较为稳定的腙类化合物(图1)的性质,采用GC、HPLC法对该腙类化合物进行测定.     

Determination of Fenofibric Acid in Human Plasma by LC–MS/MS and LC–UV

A sensitive, high-throughput and economic liquid chromatographic method for determination of fenofibric acid in human plasma was developed and validated by ultraviolet detection and tandem mass spectrometry, then applied in pharmacokinetic study to investigate Lipanthyl™ 200 mg MC bioavailability under food and fasting conditions. Fenofibric acid with 2-chloro fenofibric acid-d6 (internal standard) was extracted from 100 µL of human plasma by acetonitrile in a single extraction step. 25 and 2 µL from supernatant were injected onto ACE column, 50 mm, 5 micron with 4.6 mm inner diameter for LC–UV and 2.1 mm for LC–MS/MS, and both systems were eluted isocratically by water:methanol:formic acid (35:65:0.1, v/v/v), with a constant flow rate of 1 mL min⁻¹. The established calibration curve was linear between 0.05–20 µg mL⁻¹, and the within- and between-day precisions were all below 13 % in both LC–MS/MS and LC–UV systems during validation, and accuracies ranged between 91 and 112 %. Twenty-eight healthy adult subjects participated in this clinical study, and the pharmacokinetic parameters including coefficient of variation were calculated and discussed. A dramatic decrease in C _max and AUC0-72 (3.63- and 1.85-fold, respectively) were observed for Lipanthyl™ MC under fasting conditions with more variable inter subject measurements comparing to the fed state.

     

LC/MS/MS方法筛查新生儿苯丙酮尿症

苯丙酮尿症 [1～ 4 ] ( PKU )发病原因是患者基因缺陷使肝脏不能合成苯丙氨酸羟化酶而导致体内苯丙氨酸 ( Phe)不能正常代谢为酪氨酸 ( Tyr) ,前者在体内大量堆积并氧化为对人体有害的苯丙酮酸 . PKU是目前筛查范围最广的氨基酸代谢遗传疾病 ,在全世界每年 [5]约有一千万婴儿接受 PKU筛查 ;在我国 ,PKU也是卫生部要求重点筛查的病种 .Chace[5]等在 1 993年报道了 MS/ MS方法筛查新生儿PKU:直接使用 MS/ MS的中性碎片丢失扫描方式检测 Phe和 Tyr,通过氘代内标与待测氨基酸的质谱峰高比来定量 .MS/ MS方法速度快、准确性好、可以…     

LC–MS/MS法检测黑色粮谷类食品中的苏丹黑B和苏丹红B

采用液相色谱串联质谱(LC–MS/MS)法测定黑色粮谷类食品中苏丹黑B和苏丹红B含量。用正己烷、饱和乙腈提取目标物,以乙腈饱和的正己烷去除油脂,以固相萃取柱富集净化处理,外标法定量。苏丹黑B和苏丹红B的质量浓度在5~100 ng/m L范围内与色谱峰面积呈良好的线性,线性相关系数r20.999,检出限为5μg/kg。加标回收率为90.0%~96.0%,测定结果的相对标准偏差小于1.0%(n=6)。该方法分析时间短,准确性好,适用于黑色粮谷类食品中苏丹黑B和苏丹红B含量的检测分析。     

LC/MS/MS法测定化妆品中树苔提取物

采用液相色谱-质谱法测定了化妆品中的树苔提取物,建立了化妆品中树苔提取物的检测方法,方法的检出限为10 ng/mL,被测物在10～500 ng/mL范围内线性关系良好.本方法可以用于树苔提取物在化妆品中含量的质量控制.     

Determination of Eleutherosides in Dietary Supplements by LC–MS/MS

A simple and specific method for the simultaneous determination of eleutherosides B and E in powdered rhizomes of Eleutherococcus senticosus extract and in solid and liquid dietary supplements was developed and validated. E. senticosus extracts, often mixed with other plants or herbal extracts, are widely used in food supplements because of the tonic and adaptogenic activities referred to the eleutherosides B and E. In this study, samples were analyzed by a liquid chromatography-electrospray tandem mass spectrometry (LC–ESI-MS/MS) method operated in single reaction monitoring (SRM). Validation was carried out in terms of limit of detection (LOD), limit of quantitation (LOQ), linearity, precision and trueness. LOD and LOQ values were fixed at 3 μg L^?1 and 10 μg L^?1, respectively, whereas linearity was established within 10–1,000 μg L^?1 range for both compounds. Good precision was obtained for both eleutherosides in terms of intra-day precision (RSD % lower than 4 %) and inter-day precision (RSD % lower than 6 %). Good percentage recoveries were obtained for both eleutherosides (91.5–103.6 %). Finally, the developed method was successfully applied to analyze a number of solid and liquid commercial dietary supplements containing E. senticosus extracts, also mixed with other herbal extracts.     

Stress Studies and Identification of Degradation Products of Cephalexin Using LC–PDA and LC–MS/MS

A stability indicating RP-HPLC method for cephalexin has been developed and validated to identify and characterize potential degradation products. Drug was subjected to hydrolytic (acidic, basic, and neutral), oxidative, thermal, and photolytic stresses as per ICH guidelines Q1A (R2) and Q1B. Chromatographic separation was achieved on C8 column with mixture of ammonium acetate buffer pH 4.5 and acetonitrile in gradient mode as a mobile phase with PDA detection. Specificity of the method was established by peak purity studies. Method was validated as per ICH guideline Q2 (R1) for accuracy, precision, linearity, sensitivity, and robustness. Kinetics for each degradation condition was studied with respect to order of reaction and rate constant. Method was found to comply with acceptance criteria of validation parameters with respect to specificity (peak purity greater than 0.999) linearity (r ² greater than 0.99), accuracy (% recovery in the range of 98–102%), and precision (% RSD not more than 2). A total of six degradation products were generated in different stress conditions; these were identified and structures were proposed using LC–MS/MS. Cephalexin undergoes degradation in almost all the conditions. The developed stability indicating method is suitable for analysis of stability samples as it adequately separates all degradation products. Degradation products generated in photolytic and oxidative conditions are reported for the first time.     

Analysis of 10 urinary BTEX metabolites using LC–MS/MS

Benzene, toluene, ethylbenzene, and xylene (BTEX) are a group of volatile organic compounds that are ubiquitous in the environment due to numerous anthropogenic sources. Exposure to BTEX poses a health hazard by increasing the risk for damage to multiple organs, neurocognitive impairment and birth defects. Urinary BTEX metabolites are useful biomarkers for the evaluation of BTEX exposure, because of the ease of sampling and their longer physiological half-lives compared with parent compounds. A method that utilizes LC–MS/MS was developed and validated for simultaneously monitoring of 10 urinary BTEX metabolites. During the sample preparation an aliquot of urine was diluted with an equal volume of 1% formic acid; internal standard solution was added, and then the sample was centrifuged and analyzed. The analytes were separated on the Kinetex-F5 column by applying a linear gradient, consisting of 0.1% formic acid and methanol. The method was validated according to the FDA Bioanalytical Method Validation Guidance for Industry. The mean method's accuracies of the spiked matrix were 81–122%; the inter-day precision ranged from 4 to 20%; the limits of quantitation were 0.5–2 μg/L. The method was used for the evaluation of baseline levels of urinary BTEX metabolites in 87 firefighters.     

卷烟主流烟气中相关成分含量的快速检测方法

建立了一种快速测定卷烟主流烟气中相关成分的方法,其中包括一氧化碳、4-(甲基亚硝氨基)-3-吡啶-1-丁酮(NNK)、苯酚、巴豆醛、氨和氰化氢6种相关成分.采用在吸烟机上同时使用溶剂捕集和滤片捕集的方式,溶剂捕集氨、氰化氢和巴豆醛,滤片捕集NNK、氨、氰化氢和苯酚,样品采集后分别在高效液相色谱、离子色谱和液相色谱/质谱...