A novel pre-column fluorescent derivatization method for the sensitive determination of aristolochic acids in medicinal herbs by high-performance liquid chromatography with fluorescence detection

Aristolochic acids (AAs) are a family of structurally related nitrophenanthrene carboxylic acids existing in Aristolochia, Bragantia, and Asarum species. AAs have been proven to have nephrotoxic and carcinogenic toxicity. In this study, a novel pre-column fluorescence derivatization procedure followed by high-performance liquid chromatography-fluorescence detection (HPLC-FLD) is developed for the analysis of AAs in medicinal herbs. The nitro group in the phenanthrene ring of AAs was removed by NaBH₄ in water–THF (2:1, v/v), resulting in the corresponding aristolic acids. The analysis of AAs in medicinal herbs was based of the sensitive fluorescence detection of aristolic acids after the chemical derivatization. Because the produced aristolic acids are highly fluorescent the limit of detection (LOD) of AAI and AAII were lowered to 0.06 and 0.04 ng/mL, respectively, which is at least an order of magnitude lower than those in the reported HPLC and LC–MS methods. Good linearity with correlation coefficients higher than 0.997 were obtained for AAI and AII in the calibration ranges of 0.2–800 ng/mL. The derivatization conditions such as reaction temperature, time and the amount of NaBH₄ were optimized. The developed method provided satisfactory intra-day and inter-day precisions with RSDs less than 1.4% and 3.8%, respectively. The relative analytical error was less than 7% for the analysis of AAI and AAII in spiked matrix samples.     

多功能柱净化-光化学柱后衍生高效液相色谱测定食品中黄曲霉毒素

目的:研究建立了光化学柱后衍生-高效液相色谱-荧光检测器测定食品中黄曲霉毒素B1、B2、G1和G2的方法。方法:乙腈/水提取样品中黄曲霉毒素B1、B2、G1和G2,经多功能柱净化、高效液相色谱分离、光化学柱后衍生,荧光检测器测定。结果:黄曲霉毒素B1、B2、G1和G2的检出限分别为0.50μg/kg、0.15μg/kg、0.50μg/kg和0.15μg/kg,回收率为86.7%～97.2%,相对标准偏差(RSD)0.41%～2.40%。结论:该方法简便快速、灵敏度高、重现性好,满足食品中黄曲霉毒素检测的需要。     

Quantification and validation of nine nonsteroidal anti‐inflammatory drugs in equine urine using gas chromatography–mass spectrometry for doping control

Nonsteroidal anti‐inflammatory drugs (NSAIDs) are commonly used in therapeutic doses in human and veterinary medicine for the treatment of inflammation, pain, and fever. A method for the simultaneous determination of nine NSAIDs, known as therapeutic prohibited substances, in equine urine was developed and fully validated according to the European Commission Decision 2002/657/EC and Association of Official Racing Chemists criteria. The validation was performed for naproxen, flunixin, ketoprofen, diclofenac, eltenac, meclofenamic acid, phenylbutazone, vedaprofen, and carprofen in equine urine in accordance with the International Screening Limits (ISL) regulated by International Federation of Horseracing Authorities. After basic hydrolysis, samples were extracted with a C18 cartridge using automated solid‐phase extraction. Several derivatization reagents were investigated, and trimethylphenylammonium hydroxide/methanol (20/80, v/v) was selected. Analyses were carried out using gas chromatography–mass spectrometry with selected ion monitoring mode, but the method can be applied to a large number of analytes. The within‐laboratory reproducibility was not more than 12.8% (≤15%), and mean relative recoveries ranged from 91.1% to 104.1% for inter‐day and intra‐day precision. The decision limits (CCα) and detection capabilities (CCβ) were evaluated at concentrations near the ISL for each therapeutic substance. The validation results demonstrated that the method is highly reproducible, easily applicable, and suitable for the analysis of some NSAIDs in equine urine that have not been previously published. Finally, the method was also applied to known positive samples.     

A new approach to quantitative determination of γ-glutamyl-valyl-glycine in various aquatic products

A new method for determining the content of γ-glutamyl-valyl-glycine (γ-Glu-Val-Gly, γ-EVG) using high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) with precolumn derivatization by 2,4-Dinitrochlorobenzene (CDNB) was developed. The method exhibited satisfactory linear relationship (R² = 0.9995) at concentrations ranging from 1.0 to 40.0 ng/mL. The limits of detection (LOD) and quantitation (LOQ) were 0.3 and 0.9 ng/mL, respectively. Recoveries of the target peptide in spiked samples were between 83.05% and 116.49%, showing the values of relative standard deviation (RSD) less than 10%. The intra-day and the inter-day precisions were calculated to be 7.13% and 8.54% (n = 6), respectively. The validated approach was effectively applied to quantify the γ-EVG levels (0.13–0.38 μg/g) in different aquatic products. In conclusions, a sensitive, low-cost, convenient and reliable approach was developed for the detection of γ-EVG, which can serve as a potential tool for evaluating flavor peptide quality of aquatic products.     

柱前衍生HPLC法测定五谷虫中脂肪酸含量

目的 建立HPLC法测定五谷虫中脂肪酸含量的方法.方法 采用2-溴代苯乙酮作为衍生化试剂,三乙醇胺作为催化剂对脂肪酸进行衍生化使其产生紫外吸收,利用HPLC法进行含量测定.色谱条件为Agilent-C18柱(250 mm×4.6 mm,5 μm);检测波长254 nm;流动相为水∶甲醇=10∶90;柱温为20 ℃;体积流量为1 mL/min,进样量为20 μL,内标为十七烷酸.结果 在上述色谱条件下,各脂肪酸衍生物均达到基线分离.亚油酸的含量为131.0 mg/L,软脂酸的含量为194.8 mg/L,油酸的含量为100.6 mg/L,硬脂酸含量为36.6 mg/L.结论 该方法稳定,重现性好,可用于五谷虫脂肪酸含量测定.     

HPLC柱前衍生法测定舒血宁注射液中四种氨酸的含量

[目的]建立舒血宁注射液中4种氨基酸(天门冬氨酸、苏氨酸、丙氨酸、甲硫氨酸)的高效液相色谱(HPLC)柱前衍生化法,为舒血宁注射液的质量控制提供方法。[方法]以异硫氰酸苯酯(PITC)为柱前衍生化试剂,采用C18色谱柱,乙腈-水(5∶1)-乙酸铵缓冲溶液(p H 6.5)为流动相,梯度洗脱,检测波长为254 nm,测定舒血宁注射液中天门冬氨酸、苏氨酸、丙氨酸、甲硫氨酸的含量。[结果]4种氨基酸的分离及线性关系良好,精密度,重复性,稳定性RSD均都小于5%,平均回收率在95.6%~98.9%之间且RSD小于5%。舒血宁注射液中4种氨基酸总含量为1 738.47μg/mL。其中甲硫氨酸含量最高,丙氨酸的含量最低。[结论]本方法简便、准确、可靠,适用于舒血宁注射液中氨基酸含量的测定。     

柱前衍生化HPLC法测定复方氨基酸注射液(20AA)中氨基酸含量

目的: 建立柱前衍生高效液相色谱法测定复方氨基酸注射液（20AA）中包括门冬酰胺和盐酸鸟氨酸在内的18种氨基酸含量的方法。方法: 以6-氨基喹啉-N-羟基琥珀酰亚胺基氨基甲酸酯（AQC）为衍生化试剂,以γ-氨基丁酸为内标,采用Kromasil C18(250 mm × 4.6 mm, 5?m)色谱柱,以140 mmol?L-1醋酸铵缓冲液(pH5.10)和乙腈-水(57∶43)溶液为流动相进行梯度洗脱,检测波长为248 nm,进样量5?L。结果: 18种氨基酸在1.2～108.8 ?g?mL-1范围内浓度与峰面积线性相关,相关系数为0.994 7～0.999 7;在标示浓度的80％、100％、120％三个浓度水平的平均回收率为97.4％～103.1％,RSD为1.3％～3.7％(n=9)。结论: 本法操作简便,结果准确,优于现行标准的方法。     

Fluorescence detection of biotin using post-column derivatization with OPA in high performance liquid chromatography

A sensitive and selective high-performance liquid chromatographic method with post-column derivatization, using o-phthalaldehyde (OPA) and 3-mercaptopropionic acid (3-MPA), is described for the determination of biotin in pharmaceutical preparations. The use of 3-MPA gives intense fluorescent derivative and improves the stability of biotin fluorophore towards oxidation to the picomole level. The fluorophore was detected at 453 nm (excitation at 342 nm). The calibration graph was linear for 20–200 ng per injection. The detection limit of biotin under these conditions was about 10 ng per injection. The RSDs were 1.9–3.4%. This method could be applied to pharmaceutical preparations without interference of other compounds.     

盐酸芬氟拉明对映体的柱前衍生物GC法分析

以ω－莰烷酰氯为衍生试剂,采用柱前衍生化ＧＣ法,成功地分析了盐酸芬氟拉明、金刚乙胺和盐酸氯胺酮。光谱分析确证了芬氟拉明酰胺衍生物的结构,优化了盐酸芬氟拉明酰胺衍生物的结构,优化了盐酸芬氟拉明衍生条件,建立了盐酸花氟拉明的内标法定量分析方法。     

用均匀设计法优化β—环糊精手性固定相的衍生化反应工？…

采用均匀设计法对衍生化β－环糊精（β－ＣＤ）键合固定相的合成条件进行优化,考察的主要因素包括衍生化试剂异氰酸苯酯的用量、反应时间及反应温度。衍生化后β－ＣＤ键合相的碳含量优化结果预测值和实测值分别为１７．９５％和１８．１０％。采用红外光谱、热重分析曲线对衍生化前后β－ＣＤ键合固定相进行表征,探讨了衍生化前后β－ＣＤ键合相的手性拆分能力。