同位素稀释凝胶渗透色谱-气相色谱-质谱法测定膳食样品中16种邻苯二甲酯类物质

建立膳食样品中16种邻苯二甲酸酯的同位素稀释凝胶渗透色谱净化(GPC)-气相色谱(GC)-串联质谱(MS)检测方法。方法 加入同位素内标的膳食样品用正己烷饱和过的乙腈超声提取,GPC净化,DB-5ms 毛细管色谱柱分离(30m×0.25mm,0.25μm),GC-MS选择离子监测模式(SIM)测定,内标法定量。结果 16种邻苯二甲酸酯在8类膳食样品中的平均添加回收率为52.3%～124.7%;RSD为1.6%～16.2%;检出限为0.03～0.06mg/kg。结论 该方法简便、灵敏、准确,适用于膳食样品中邻苯二甲酸酯的检测。     

碱解法测定动物水解蛋白中L-羟脯氨酸的含量

目的 建立了使用聚四氟乙烯带盖水解管,以NaOH溶液为水解液的碱解法测定动物水解蛋白中L-羟脯氨酸(L-Hydroxyproline,L-Hyp)含量.方法 将样品置于10 ml水解管中,加入6 ml 2.5 mol/L NaOH溶液在110℃烘箱中加热2h,水解出的L-Hyp经氯胺T氧化后与对二甲氨基苯甲醛反应生成红色络合物,在(558±2) nm处测定其吸光度.结果 在优化实验条件下,该方法的线性范围0～10 μg/ml(r =0.999 3),检出限1.35 μg/g,样品测定的RSD在1.0％ ～2.3％,加标回收率为88.7％～96％(加标量为30 mg/kg).结论 相对酸解法,碱解法的水解效率和酸解法基本一致,样品前处理操作简单,缩短了测定时间,灵敏度、重复性和稳定性良好.     

QUANTIFICATION OF BINARY MIXTURES OF COCAINE AND ADULTERANTS USING DISPERSIVE RAMAN AND FT-IR SPECTROSCOPY AND PRINCIPAL COMPONENT REGRESSION

Current forensic methods for detecting and identifying cocaine and its adulterants are destructive, so evidence cannot be re-analyzed. Vibrational techniques [Raman and Fourier transform infrared (FT-IR) spectroscopy] allow rapid, economical, nondestructive analysis. This work compares these techniques as methods for quantifying mixtures of cocaine (in the crack presentation) and adulterants. The aim is to provide a method to determine the amount of cocaine in crack rocks and to identify and quantify possible adulterants. A sample of crack was adulterated with benzocaine, caffeine, sodium carbonate, and lidocaine to create binary mixtures of concentrations of 20%, 40%, 60%, and 80%; pure samples of each adulterant and of crack were also examined. All samples were observed using dispersive Raman and attenuated total reflectance FT-IR spectroscopy. Quantitative analysis was performed based on principal component regression (PCR) applied to simulated and real spectra. The PCR model revealed that the Raman spectra yielded only minor measurement errors and the highest correlations using the PC2 spectral vector, which presented spectral features of cocaine. Among the mixtures, the best and worst results were obtained for caffeine and sodium carbonate, respectively. Dispersive Raman spectroscopy outperformed FT-IR in the quantitative determination of binary mixtures of cocaine and adulterants.     

Implication of palynological techniques for the authentication of adulterated drugs traded with the same name in different herbal markets of district Lahore,Pakistan

Adulteration in traded medicinal plants is a significant issue nowadays and use of these adulterated medicinal plants can impose harmful impact to end user. However, this problem can be overcome by ensuring the identification of traded medicinal plants which are used in making different herbal medicines. In this regard, palynological markers are considered to be an important taxonomic tool in the identification of original medicinal plant from its adulterant. Hence this study attempted to provide particular reliable palynological markers for distinguishing selected medicinal plants from their adulterants, that is, Cinnamomum verum versus Canella winterana, Cinnamomum tamala versus Cinnamomum obtusifolium, Gymnema sylvestre versus Gymnema lactiferum, Artemisia maritima versus Artemisia absinthium, Achillea millefolium versus Adhatoda vasaka, Sphaeranthus indicus versus Sphaeranthus africanus, Averrhoa carambola versus Butea monosperma, and Morus nigra versus Morus alba. Results demonstrated great variations in multiple palynological characters between original medicinal plant and its adulterant such as in pollen size, shape, colpi length, exine, intine thickness, and fertility. In equatorial view, circular to spheroidal shape of pollen was found in A. millefolium while oblate shape was observed in A. vasaka. Similarly B. monosperma pollen was 34 μm, whereas pollen of its adulterant A. carambola was 21 μm. Moreover, colpi length of A. maritima was 11.8 μm, whereas 4.5 μm in A. absinthium. Hence it can be concluded that palynological characters are commendably helpful in identification of genuine medicinal plant from its adulterant.     

Enzyme immunoassay for the detection of porcine gelatine in edible bird’s nests

Porcine gelatine is a common adulterant found in edible bird’s nests (EBNs) used to increase the net weight prior to sale. This study aimed to develop indirect enzyme-linked immunosorbent assays (ELISAs) for porcine gelatine adulteration using anti-peptide polyclonal antibodies. Three indirect ELISAs were developed (PAB1, 2 and 3), which had limits of detection (LODs) of 0.12, 0.10 and 0.11 µg g^–1, respectively. When applied to standard solutions of porcine gelatine, the inter- and intra-assays showed coefficients of variation (CVs) less than 20% and were able to detect at least 0.5 ng µg^–1 (0.05%) porcine gelatine in spiked samples. The proposed ELISA offers attractions for quality control in the EBN industry.     

基于matK基因序列的高良姜及其混淆品的鉴定

研究了通过matK基因测序对高良姜和大高良姜进行鉴定的方法.结果表明,两个山姜属品种的15个样品的部分matK基因序列共有21个位点的核苷酸替换,根据核苷酸位置12、211、291、411、 440、 618、 631、684、686、 847、844、 921、954、988、1 011、 1 076、1 103和1 116的序列可以区别高良姜与大高良姜,即这18个核苷酸位点是鉴别它们的核苷酸标记;高良姜matK基因序列的种内变异很小,没有发现可以区分不同产地高良姜的核苷酸位点.研究数据为进一步建立快速、简便的高良姜分子鉴定方法提供了依据.     

Rapid and Sensitive Identification of the Herbal Tea Ingredient Taraxacum formosanum Using Loop-Mediated Isothermal Amplification

Taraxacum formosanum (TF) is a medicinal plant used as an important component of health drinks in Taiwan. In this study, a rapid, sensitive and specific loop-mediated isothermal amplification (LAMP) assay for authenticating TF was established. A set of four specific LAMP primers was designed based on the nucleotide sequence of the internal transcribed spacer 2 (ITS2) nuclear ribosomal DNA (nrDNA) of TF. LAMP amplicons were successfully amplified and detected when purified genomic DNA of TF was added in the LAMP reaction under isothermal condition (65 °C) within 45 min. These specific LAMP primers have high specificity and can accurately discriminate Taraxacum formosanum from other adulterant plants; 1 pg of genomic DNA was determined to be the detection limit of the LAMP assay. In conclusion, using this novel approach, TF and its misused plant samples obtained from herbal tea markets were easily identified and discriminated by LAMP assay for quality control.     

纸喷雾离子化质谱法快速筛查保健食品中违禁添加的磷酸二酯酶5抑制剂

目的建立纸喷雾离子化质谱(PSI-MS)法快速检测保健食品中3种非法添加的磷酸二酯酶5(PDE5)抑制剂(西地那非、伐地那非和他达拉非)的方法。方法利用PSI-MS法对样品中非法添加物进行初步定性鉴别,并通过内标法进行半定量分析。结果 24种包括胶囊、片剂、丸剂、粉末、酒剂、糖浆及口服液等剂型在内的待测市售保健品的PSI-MS检测结果与HPLC-UV检测结果基本一致。各目标物在一定范围内线性关系良好,相关系数r~2均0.99,检出限均在1.0 mg/L以下,相对标准偏差为20%~24%。结论本方法快速、准确、专属性强,适用于大批量复杂基质样品中PDE5抑制剂的快速筛查。     

高效液相色谱-二极管阵列法测定保健酒中的萘普生

近期不断发现抗炎药物被违法添加到抗风湿保健酒中增加治疗效果,这种现象对消费者健康构成威胁。萘普生是常用非甾体抗炎药物,本研究建立保健食品中违禁添加萘普生的液相检测方法。通过酸性条件氯仿和碱性水溶液两步液-液萃取,从保健酒中提取和净化萘普生。使用Kromasil 100-5C18(250×4.6 mm E74572)色谱柱,以甲醇-0.01M磷酸缓冲液(pH 3.0)(75/25,V/V)流动相,流速为1.0 mL/min进行分离;检测波长为231 nm。通过比对色谱峰保留值和加标实验,结合二极管阵列扫描图谱对可疑样品定性,并根据外标法峰面积定量检测萘普生含量。检品和基质成分基本实现了基线分离,最低检测限为0.5μg/mL,工作曲线的线性范围:5~80μg/mL(R2=0.9993),RSD为1.87%(n=6),加标回收率83.3~92.6%。方法准确、可靠,适用于检测保健品中违法添加的萘普生。     

茶叶掺杂物中CaO、MgO的测定

本文提出以CaO、MgO作为检测茶叶掺杂物石膏、滑石粉的标识物,采用干灰化法处理茶样,并用络合滴定法对CaO、MgO进行测定,经长期实际检测表明,检测结果稳定可靠,并经与火焰原子吸收分光光度法比对,结果满意。该法简便易用,适合一般茶叶厂家及相关检测部门采用。