Analysis of Monosaccharide Composition of Pu-erh Tea Polysaccaride by Pre-column Derivatization HPLC

[Objective] This study aimed to establish a pre-column derivatization HPLC method for the identification and analysis of monosaccharide composition of Pu-erh tea polysaccharide. [Method] Pu-erh tea polysaccharide was extracted using the wa- ter extraction method, further isolated and purified by DEAE cellulose-52 columns. The obtained tea polysaccharide and four components TPS1, TPS2, TPS3 and TPS, were first derived by 1-phenyl-3-methyl-5-pyrazolone （PMP）, and then the PMP derivatives of monosaccharide were analyzed by high performance liquid chromatog- raphy （HPLC）. [Result] Pu-erh tea polysaccharide contained eight kinds of monosac- chaddes （mannose, rhamnose, glucuronic acid, galacturonic acid, grucose, galactose, arabinose, fucose）, without xylose; so it was the same with TPS1; each of TPS2, TPS3 and TPS4 contained seven monosaccharides, while no fucose. [Conclusion] This method is simplified and rapid, which can be used to determine the monosac- charide composition of Pu-erh tea polysaccharide and monosaccharide content.

Determination of Sparfloxacin in Human Urine by Reversed-Phase High Performance Liquid Chromatography With Nitrous Acid and Hydroiodic Pre-Column Derivatization

Sparfloxacin can be oxidized by nitrous acid, then react with hydroiodic acid to form a fluorescent derivative. Based on this, a reversed-phase high performance liquid chromatographic pre-column derivatization new method is described for the determination of sparfloxacin in human urine. The linear range is 0.05 mg/L to 4.0 mg/L, the recoveries are 91.5%similar to 95.7% and the RSD is 1.2%similar to4.2%. The results showed that this method is suitable for the determination of sparfloxacin in human urine.

Determination of 18 Kinds of Amino Acids in Fresh Tea Leaves by HPLC Coupled with Pre-column Derivatization

A rapid and accurate quantitative method of high performance liquid chromatography( HPLC) with fluorescence detector has been developed for the analysis of 18 kinds of amino acids in fresh tea leaves. The samples were minced and mixed,and extracted with ultra pure water at 90℃ for 20 min. The 6-aminoquinolyl N-hydroxy-succinimidyl carbamate( AQC) was used as pre-column derivatization reagent. Gradient HPLC separation was performed on a C_(18) column( Symmetry C_(18),3. 9 mm × 15 cm,4 μm). Good linearity between concentrations and peak areas was achieved in the concentration range of 5. 0-250 μmol/L for 18 kinds of amino acids. The method was validated by the analysis of five replicates. The 18 kinds of amino acid standards were spiked in fresh tea leaf samples and the average recovery rate was 86. 25%-109. 05% with relative standard deviations( n = 5) ranging from 6. 03% to 10. 56%. The limit of detection( LOD) for the analytes was0. 05-1. 27 μmol/L. The method was successfully applied to the analysis of the 18 kinds of amino acids in fresh tea leaves from east Dongting and west Dongting mountains in Suzhou. The results indicate that the method is simple,rapid,precise and reliable.

Enantioresolution of a Series of Chiral Benzyl Alcohols by HPLC on a Dinitrobenzoylphenylglycine Stationary Phase after Achiral Pre-Column Derivatization

High performance liquid chromatography method for the separation of a series of chiral benzyl alcohols on N-(3,5-dinitrobenzoyl)-D-phenylglycine stationary phase (Macherey Nagel, Chiral-2) after pre-column achiral derivatization was developed. Cheap and easy available aromatic acid chlorides were used as derivatization agents. Good to excellent separations of the enantiomers were achieved in all cases in relatively short analytical runs. It was shown that the enantiorecognition depends on the substituents both in the starting alcohol and in the acid chloride. The method presents an efficient alternative to the direct analyses on polysaccharide and cyclodextrine-derived stationary phases.

HPLC of Amino Acids and Oligopeptides by Pre-Column Fluorescence Derivatization with 9-Acridine Formyl Chloride

A highly sensitive HPLC method for the detection of amino acids and oligopeptides with 9-acridine formyl chloride by pre-column fluorescence derivatization has been developed. Glycine, glycylglycine, histidine, triglycine and glutathione were separated on a reversed-phase C-18 column with methanol-water-triethylamine eluent, derivatization and chromatographic conditions were optimized. The five derivatives were eluted in 28 min with a good reproducibility. Linear range of the calibration graph was 0.08-260 nmol/ml(-1). The relative standard deviations(n=6) are < 5%. Detection limits (signal-to-noise ratio=3) for the five derivatives are 20-40 fmol.

Contents Variation Analysis ofγ-Amino Butyric Acid in Semen sojae praeparatum Fermentation Using Online Pre-Column Derivatization-HPLC

This paper reported the contents variation analysis ofγ-amino butyric acid(GABA)in Semen sojae praeparatum(SSP)which is a famous traditional Chinese medicine.High performance liquid chromatography(HPLC)was used and GABA was derivatized by online pre-column derivatization with o-phthalaldehyde(OPA).To validate this method,the precision,stability,repeatability and recovery were discussed.In the concentration range from 0.0125 to 0.400 mg/m L,the calibration curve for GABA was linear and the regression equation was obtained with correlation coefficient(R2)of 0.9999.Relatively high levels of GABA exist in SSP and the content changes of GABA at different time points during the fermenting process were detected.At the"yellow cladding"stage,GABA level was very low or even undetectable;the"secondary fermentation"stage witnessed a rapid increase of GABA content to 1.39-5.52 mg/g,which remained stable after 18 days of"secondary fermentation".This study demonstrated that GABA was generated at the"secondary fermentation"stage,revealing the significance and rationality of the"secondary fermentation"stage in the fermenting process of SSP.On the other hand,it suggested the downside of taking soy isoflavones as the only measurement in existing quality assessment and optimization approach for the fermenting process of SSP.

瓜蒌皮注射液及其中间体中17种氨基酸含量测定及其变化规律研究

目的测定瓜蒌皮注射液及其中间体中天冬氨酸、谷氨酸、丝氨酸、甘氨酸、苏氨酸、瓜氨酸、精氨酸、丙氨酸、γ-氨基丁酸、酪氨酸、缬氨酸、苯丙氨酸、异亮氨酸、鸟氨酸、亮氨酸、赖氨酸、脯氨酸的含量,并分析其变化规律。方法OPA-FMOC在线衍生化分析采用Waters XBridge C_(18)色谱柱(4.6 mm×100 mm,3.5μm);流动相磷酸盐缓冲液-[甲醇-乙腈-水(45∶45∶10)],梯度洗脱;体积流量1 mL/min;柱温45℃;检测波长262、338 nm。主成分分析、热图分析对10道工序相应中间体的6批样品进行化学模式识别。结果17种氨基酸在各自范围内线性关系良好(R^(2)>0.9980),平均加样回收率83.4%~119.5%,RSD 0.91%~7.94%。相同工序不同批次样品较聚集,不同工序相应中间体聚为3组。醇沉和阳离子交换柱对氨基酸组成影响最大。结论本实验可为瓜蒌皮注射液质量控制的关键因素提供重要参考,以保证终产品的稳定性和均一性。

柱前衍生-高效液相色谱法检测魔芋飞粉中的神经酰胺

建立了一种柱前衍生-高效液相色谱测定魔芋飞粉中神经酰胺的方法。将神经酰胺与氢氧化钾乙醇溶液在高温条件下进行脱酰基反应,再与9-氯甲酸芴甲酯(FMOC-Cl)衍生化试剂反应,高效液相色谱分离后,采用紫外或荧光检测器检测。考察并确定了脱酰基以及衍生化反应的最佳条件,在110℃条件下用0.5 mol/L氢氧化钾乙醇溶液对神经酰胺标品或样品处理1.5 h,然后用10 mg/mL的FOMC-Cl对其进行在线衍生。采用Waters Symmetry C18柱(250 mm×4.6 mm, 5μm)分离,甲醇/水/磷酸(体积比10/90/0.05)-甲醇为流动相进行梯度洗脱,荧光检测器的激发波长和吸收波长分别为266 nm和305 nm;紫外检测器波长为262 nm。在神经酰胺浓度为20~500μg/mL范围内方法的线性关系良好,其中紫外检测器检测的相关系数(R^(2))为0.9978,荧光检测器检测的R2为0.9978,回收率为97.3%~103.6%,相对标准偏差<1.64%。所建立方法采用紫外和荧光检测器测定目标物的检测限分别为0.48μg/mL和0.0082μg/mL,定量限分别为1.6μg/mL和0.027μg/mL。

改良QuEChERS/HPLC-光化学在线衍生荧光检测法测定猪肉中18种磺胺类药物残留量

建立了猪肉中磺胺类药物的改良Qu ECh ERS/高效液相色谱-光化学在线衍生荧光检测方法。样品用1%乙酸-乙腈溶液提取,PSA,C18和石墨化碳黑（GCB）混合粉末作为吸附剂,Qu ECh ERS净化后进行HPLC分析,以Platisil ODS色谱柱（4.6 mm×250 mm,5μm）分离,在线光化学衍生后进入荧光检测器检测。选择激发波长为320 nm,发射波长为450 nm,柱温36℃,流动相为0.3%冰乙酸-甲醇,梯度洗脱,可实现18种待测组分的基线分离。在优化实验条件下,18种磺胺类药物的质量浓度在0.05~110.28μg·m L-1范围内与其峰面积呈良好线性,相关系数均大于0.992 0。方法检出限（S/N=3）为1~18μg·kg-1,定量下限（S/N=10）为3~60μg·kg-1。加标水平为0.02~4.49 mg·kg-1时,猪肉中18种磺胺类药物的平均回收率为71.2%~113.4%,绝大部分集中在80%~100%之间,相对标准偏差（RSD）为0.8%~8.7%。该方法前处理快速简便、选择性强、有机溶剂用量少,检测可靠,准确性和灵敏度高,适用于猪肉中磺胺类药物残留的快速检测。

高效液相色谱光化学在线衍生荧光法检测鸡肉中16种磺胺类药物残留

采用高效液相色谱-光化学柱后在线衍生-荧光检测法检测鸡肉中16种磺胺类药物残留量。鸡肉样品经过乙腈提取并脱脂净化,色谱柱分离,光化学在线衍生并直接用荧光检测器检测。流动相为0.3%的冰乙酸和甲醇溶液梯度洗脱,流速0.7 m L/min、柱温36℃,激发波长320 nm、发射波长450 nm,16种磺胺类药物得到良好分离。16种磺胺药物在0.13~67.89μg/m L质量度范围内,线性良好（R≥0.994 0）,回收率在61.2%~106.6%之间,相对标准偏差为0.3%~13.9%,检出限为1.0~67.4μg/kg。该方法灵敏、准确、快速,可满足鸡肉中磺胺类残留的检测。

柱前在线衍生-反相高效液相色谱内标法快速测定饲料中氨基酸

采用邻苯二甲醛和氯甲酸芴甲酯联合柱前在线衍生，用反相C18短柱梯度洗脱，二极管阵列检测器（用于检测胱氨酸和赖氨酸）和荧光检测器（用于检测其它氨基酸）联合检测，建立了一种高效液相色谱内标法快速测定饲料中氨基酸含量的方法。此方法对传统样品水解液制备的方法进行了简化，在不须预先除去干扰物质的情况下，提高了氨基酸测定的准确度，18种氨基酸除胱氨酸和色氨酸未检出（完全被破坏）和蛋氨酸为87．32％（部分被氧化破坏）外，其它氨基酸的回收率为94．14％-102．25％，相对标准偏差为2．11％-4．52％（n=5）；线性相关性好（相关系数为0．9900—0．9995）；线性范围为4．5—1000μmol／L；方法检出限低，灵敏度高，分离时间短，适合饲料中氨基酸的快速测定。

在线柱后衍生-高效液相色谱-荧光检测法同时测定牛肉中16种磺胺类药物残留

在考察了荧光胺、邻苯二甲醛、异硫氰酸荧光素和2,3-萘二醛等对磺胺类药物衍生效果的基础上,建立了采用改良QuEChERS方法进行样品前处理,荧光胺在线柱后衍生,高效液相色谱-荧光检测法测定牛肉中16种磺胺残留量的方法。牛肉样品经1%（v/v）乙酸乙腈溶液提取,改良QuEChERS方法净化后取上清液进样,与荧光胺柱后在线衍生,荧光检测器检测。实验结果表明,16种磺胺类药物在0.024~2.533 mg/L范围内线性关系良好,相关系数（r）大于0.992,检出限为1.6~8.2μg/kg,平均加标回收率范围为66.6%~109.5%,相对标准偏差为0.9%~9.9%。该方法快速简便、灵敏度高、净化效果好,可用于牛肉中16种磺胺类药物的快速测定。

柱后紫外光解荧光衍生液相色谱法测定蔬菜中残留的15种苯脲除草剂

建立了蔬菜中15种苯脲除草剂残留的固相萃取-在线柱后紫外光分解和衍生化的高效液相色谱荧光检测分析方法。样品用乙腈提取,弗罗里硅土固相萃取柱净化,目标化合物由反相C18柱分离,经柱后紫外光分解和衍生化后进行荧光检测。对样品的前处理条件、液相色谱分离、柱后紫外光分解和衍生条件等进行了详细的研究。15种苯脲除草剂的高效液相色谱分离在乙腈-水梯度洗脱下完成,目标物的保留时间为9-31m in,线性范围内线性关系良好,相关系数为0.998 6-1.000 0;在洋葱、菠菜、黄瓜等样品中3个加标水平的平均回收率（n=3）为75.3%-121.6%,相对标准偏差为0.4%-11.6%;15种苯脲除草剂在蔬菜中的检出限为0.005-0.05m g/kg。该方法操作简便、灵敏度高、选择性好,符合多种农药残留分析的要求。

在线凝胶渗透色谱-气相色谱-串联质谱非衍生化法测定食品中氯丙醇

建立了食品中氯丙醇类化合物的非衍生化在线凝胶渗透色谱-气相色谱-串联质谱（Online GPC-GCMS/MS）测定方法,目标化合物包括3-氯-1,2-丙二醇（3-MCPD）、2-氯-1,3-丙二醇（2-MCPD）、1,3-二氯-2-丙醇（1,3-DCP）和2,3-二氯-1-丙醇（2,3-DCP）。样品中加入氘代同位素内标后,采用ExtrelutTMNT硅藻土进行固相支持液液萃取净化,用正己烷淋洗去除非极性杂质,以乙酸乙酯萃取目标物,萃取液经浓缩后直接采用Online GPC-GC-MS/MS测定。4种氯丙醇在0.005~1.000 mg/L范围内呈良好线性,相关系数均大于0.999,4种氯丙醇的检出限在0.002~0.005 mg/kg之间,定量限在0.005~0.01 mg/kg之间。以空白酱油样品为代表性基质的3个水平（0.02,0.1和0.5 mg/kg）的加标回收率和相对标准偏差（RSD,n=6）分别为94.8%~106.3%（2.2%~10.3%）,91.8%~108.8%（2.1%~10.6%）和83.1%~109.4%（1.3%~9.4%）。采用本方法分别对酱油、水解植物蛋白液（粉）、料酒、鸡精、面包和糕点样品进行检测,均得到了满意的测定结果。

柱前在线衍生-HPLC法测定发芽糙米中γ-氨基丁酸含量

建立柱前在线衍生—高效液相色谱法(HPLC)测定发芽糙米中γ-氨基丁酸(GABA)含量的方法。样品以料液比1:5、超声功率(占总功率)60%、在30℃下超声30 min,提取2次。衍生试剂OPA与样品在线混合10次、衍生2 min,用Agilent Eclipse Plus C18柱分离(流速1 mL/min,检测波长338 nm,柱温40℃)。GABA在5~50 mg/L范围内呈良好线性关系,相关系数大于0.999 0;最低检出限0.33 mg/L,最低定量限1 mg/L,方法添加回收率94.80%~98.40%,RSD为1.82%~2.58%。该方法简单快速、灵敏度高、精确,适合发芽糙米中GABA的检测。

超声辅助萃取-大体积进样在线衍生-气相色谱串联质谱法测定食品中的苯甲酸

建立超声辅助萃取-大体积进样在线衍生-气相色谱串联质谱测定食品中苯甲酸含量的方法。采用乙腈为提取剂进行超声萃取，经离心分离后，以四丁基硫酸氢铵为衍生化试剂进行衍生，利用直接进样杆装置在气相色谱进样口进行在线衍生以提高分析灵敏度，采用DB．5MS毛细管色谱柱，通过气相色谱-离子阱串联质谱进行分析测定。结果表明：苯甲酸在0．50～10．0／ag／mL范围内线性关系良好（r=0．9976），方法的检出限和定量限分别为12．8ng／mL和42．7ng／mL。本方法具有操作简单、无需净化步骤、准确度高、重复性好等优点，可适用于食品中苯甲酸含量的测定。

柱前在线衍生-高效液相色谱法测定保健食品纳豆胶囊中的牛磺酸

建立了检测保健食品中牛磺酸的柱前在线衍生-高效液相色谱方法。样品经过去离子水提取,与邻苯二甲醛在线衍生,以A相：0.02 mmol/L的乙酸钠（pH 7.2,0.018%三乙胺,0.3%的四氢呋喃）;B相：100 mmol/L的乙酸钠（pH 7.2）20%,乙腈40%,甲醇40%为流动相,梯度洗脱,采用Thermo HypersilODSC18色谱柱（4.6mm×150mm,5μm）分离,紫外线检测。方法检出限为0.51 mg/L;标准曲线的线性范围为0-1000.0mg/L,相关系数R2=0.9992,具有良好的线性关系,加标回收率为103.9%-105.0%,相对标准偏差为0.9%-2.9%。该方法的灵敏度高、准确性好、前处理操作简单,适用于保健食品纳豆胶囊中牛磺酸含量的检测。

基于在线富集与原位衍生技术的植物组织中内源性油菜素甾醇的超高效液相色谱-串联质谱分析方法

油菜素甾醇是一类重要的植物激素,对植物的生长发育过程起显著调节作用。已报道的油菜素甾醇分析方法存在样品前处理过程复杂和灵敏度低等问题。本研究采用C18 PEEK管填充柱为富集柱,以4-N,N-二甲氨基苯硼酸为衍生试剂,搭建了基于双泵-双六通阀的在线管内固相微萃取-超高效液相色谱-串联质谱(UPLC-MS/MS)联用系统,对油菜素甾醇进行在线富集和原位衍生,实现植物组织中内源性油菜素甾醇的自动化分析。该系统程序化地控制了油菜素甾醇的进样、萃取、衍生、分离和检测过程,有效简化前处理过程,节省人力;在线富集步骤实现了样品溶液大体积进样,提高样品利用率;原位衍生改善了油菜素甾醇电喷雾的离子化效率,使油菜素甾醇的电喷雾质谱检出限降低至pg/mL。该系统可在300 mg鲜重植物组织中检测到内源性油菜素甾醇,已成功用于水稻、油菜中多种油菜素甾醇的定量分析。

分散液液微萃取-在线衍生化-气相色谱-质谱联用法检测环境水样品中紫外吸收剂

建立了分散液液微萃取（ dispersive liquid-liquid microextraction，DLLME ）-在线衍生化-气相色谱-质谱（ GC-MS）方法，将其用于环境水中6种二苯甲酮类紫外吸收剂（ BPs）（二苯甲酮、2，4-二羟基二苯甲酮、2-羟基-4-甲氧基二苯甲酮、4-羟基二苯甲酮、2-羟基-4-辛氧基二苯甲酮、2，2′-二羟基-4，4′-二甲氧基二苯甲酮）的检测。系统优化了在线衍生化的条件（如进样口温度、不分流时间、衍生化试剂用量）以及 DLLME 萃取条件（如萃取剂种类、分散剂种类、萃取剂与分散剂比例、样品体积、样品溶液离子强度及 pH 值）等。在最优的条件下，所考察的6种BPs检出限为0.011~0.15μg/L，重现性（ RSD）为0.7％-16.6％。该方法结果准确可靠，操作简单，富集效果好，成本较低，环境友好，在实际样品检测中具有一定的应用前景。

在线柱前衍生高效液相色谱法测定古树红茶中的γ-氨基丁酸

目的建立在线柱前衍生高效液相色谱法(high performance liquid chromatography,HPLC)测定古树红茶中的γ-氨基丁酸的方法。方法样品在85℃水浴中浸提2 h,石墨化炭黑(graphitizing of carbon black,GCB)净化,经自动在线柱前衍生后,用Agilent ZORBAX SB-C18(250 mm×4.6 mm,5μm)色谱柱分离,用紫外检测器于338 nm波长处进行测定。结果γ-氨基丁酸在2~80μg/m L范围内线性关系良好(r=0.9994),回归方程为Y=10.224X-17.534,加标平均回收率为95.2%~96.8%,相对标准偏差为1.7%~2.9%(n=3)。结论此方法具有良好的精密度、稳定性及回收率,可用于古树红茶中的γ-氨基丁酸测定。