高效液相色谱法测定粮食中玉米赤霉烯酮及其代谢物

采用甲醇-水提取,C18小柱净化,反相HPLC荧光检测器测定了玉米、面粉、小麦样品中的玉米赤霉烯酮及其代谢物和黄曲霉B1。对样品预处理和高效液相色谱测定条件进行了优化,ZON,α-ZOL,β-ZOL和AFTB1的线性范围分别为5.0μg/L~146g/L,25.0μg/L~200g/L,25.0μg/L~160g/L和0.4μg/L~2.0g/L,检出限分别为0.5、2.5、2.5和0.04μg/kg;加标回收率在80.0%~110.0%范围内;日间相对标准偏差为4·5%~9.2%,日内精密度2.7%~7.4%。本方法灵敏准确,易于推广,适用于粮食中玉米赤霉烯酮及其代谢物的检测。     

固相微萃取/高效液相色谱法测定水中的微囊藻毒素

采用CWX/DVB萃取头,应用固相微萃取与高效液相色谱联用技术(SPME/HPLC)分析了水溶液中的痕量微囊藻毒素。对SPME的萃取条件进行了优化,并对实际水样进行了分析。该方法测定MC-LR(LR型微囊藻毒素)的线性范围为1.00~200μg/L,相关系数为0.999 5,检出限为0.45μg/L(3σ,n=11),相对标准偏差(RSD)为2.4%,回收率为90%~99%。该方法测定MC-RR(RR型微囊藻毒素)的线性范围为1.00~100μg/L,相关系数为0.998 8,检出限为0.15μg/L(3σ,n=11),RSD为2.4%,回收率为89%~100%。     

毛细管电泳-紫外检测法同时测定食品中的葡萄糖和多种糖醇

建立了食品中葡萄糖、半乳糖醇、甘露醇、山梨醇、赤藓糖醇、木糖醇和麦芽糖醇的毛细管电泳-紫外检测同时测定方法。食品中的葡萄糖和糖醇在硼砂碱性介质中与硼酸根结合形成阴离子配合物后,在添加了电渗流改性剂十六烷基三甲基溴化铵的硼砂缓冲液(pH 9.2)中进行快速电泳分离,紫外检测器于195 nm处检测。在优化的条件下,7种物质在12 min内基线分离,标准曲线线性良好(r>0.999),检出限均低于0.1g/L,加标回收率为81.6%~120%,相对标准偏差(RSD)小于6%。方法适用于食品中葡萄糖和多种常见糖醇的同时检测。     

高效液相色谱-蒸发光散射法测定食品中的单糖、双糖、低聚果糖和糖醇

建立了食品中常用的木糖、果糖、葡萄糖、蔗糖、麦芽糖、乳糖、蔗果三糖、蔗果四糖、蔗果五糖、赤藓糖醇、木糖醇、甘露糖醇、麦芽糖醇等13种单糖、双糖、低聚果糖和糖醇的高效液相色谱同时分离检测的方法。该法采用NH₂色谱柱,以乙腈-水为流动相梯度洗脱,蒸发光散射检测器检测;13种糖在0.1~5 g/L内均具有良好的线性关系,检出限均在0.1 g/L以下,精密度(RSD)为2.69%~7.21%,回收率为96.1%~105.2%,结果较为理想。将该法用于实际样品检测,结果显示食品标签明示和实际成分相差较大。     

高效液相色谱-串联质谱法测定土壤中的氯酸盐和高氯酸盐北大核心CSCD

针对土壤样品的分析,建立了一种同时测定氯酸盐和高氯酸盐含量的高效液相色谱-串联质谱(LC-MS/MS)法。样品经过超声提取、高速离心去除杂质,上清液过固相萃取柱及滤膜净化,用液-质联用仪测定,内标法定量。氯酸盐在2.00~200 ng/mL浓度范围内线性关系良好,相关系数为0.9997,检出限为6.0μg/kg,定量限为20.0μg/kg,加标回收率在92.0%~102.5%,相对标准偏差(RSD)为2.9%;高氯酸盐在1.00~100 ng/mL浓度范围内线性关系良好,相关系数为0.9996,检出限为4.0μg/kg,定量限为10.0μg/kg,加标回收率在94.6%~108.0%,RSD为3.6%。该方法操作简单、测定结果稳定,可用于土壤中氯酸盐和高氯酸盐含量的测定。     

基于多巴胺-氧化石墨烯复合物的搅拌棒吸附萃取/高效液相色谱法测定食用油中黄曲霉毒素

建立了一种基于贻贝仿生化学涂层的搅拌棒吸附萃取/高效液相色谱/荧光检测器(SBSE/HPLC-FLD)同时测定食用油中黄曲霉毒素B1、B2、G1、G2的方法。基于贻贝仿生化学制备多巴胺-氧化石墨烯复合物固相萃取材料,利用搅拌棒吸附萃取技术对样品进行提取;以甲醇-乙腈-水(10%磷酸调至p H 3.5,体积比3∶3∶5)作为流动相,采用荧光检测器进行检测。结果显示,黄曲霉毒素B1、B2、G1、G2在0.200~10.0μg/L范围内具有良好的线性关系(相关系数r~2≥0.998 9),加标回收率为81.5%~96.9%,日内相对标准偏差(RSD)为1.7%~3.4%,日间RSD为1.9%~3.5%,方法检出限为0.025~0.050μg/L。该方法高效、灵敏、可靠,能够满足食用油中黄曲霉毒素B1、B2、G1、G2的测定要求。     

醋酸酐衍生-气相色谱-质谱联用测定葡萄酒中的糖醇

建立了先采用醋酸酐衍生然后用气相色谱-质谱联用仪检测葡萄酒中糖醇的方法。在葡萄酒中加入吡啶涡旋混合均匀,以5000 r/min (4℃)离心10 min。取上清液过有机滤膜,加入吡啶、醋酸酐衍生。加无水硫酸钠吸水后,经DB-5MS毛细管气相色谱柱分离,在选择离子监测(SIM)模式下进行检测。各目标物在0.019~1.25 mg/L (乳糖醇在0.039~2.50 mg/L)范围内线性关系良好,相关系数(r²)均大于0.99。赤藓糖醇、木糖醇、甘露糖醇、山梨糖醇、半乳糖醇和乳糖醇的定量限(信噪比(S/N)=10)分别为0.17、0.29、0.43、0.46、0.47和2.88 mg/L;检出限(S/N=3)分别为0.05、0.08、0.13、0.14、0.14和1.38 mg/L。在40 mg/L和80 mg/L加标水平下,6种糖醇在葡萄酒基质中的回收率为80.15%~108.75%,相对标准偏差(RSD)为2.16%~6.97%。该方法的灵敏度、准确度和精密度均符合相关的技术要求,适合于葡萄酒中糖醇含量的快速检测。     

衍生化毛细管气相色谱法同时测定无糖食品中的多种糖醇类甜味剂

建立了一种同时测定无糖食品中多种糖醇类甜味剂的气相色谱定量分析方法。样品中的糖醇经水提取,净化、脱水后,在吡啶-乙酸酐(1∶1,V/V)存在条件下,于90℃反应20 min,生成的糖醇乙酸酯衍生物用OV-101毛细管色谱柱(50 m×0.25 mm×0.33μm)分离,氢火焰离子化检测器(FID)进行测定及气相色谱-质谱结构鉴定。在优化的色谱分析条件下,实现了赤藓糖醇、木糖醇、甘露糖醇、山梨糖醇和麦芽糖醇衍生物的理想分离,并排除了常见糖类对糖醇测定的干扰。本方法在0.01～1.6 mg/mL范围内,对糖醇浓度与其衍生物峰面积进行线性回归分析,其相关系数在0.9995～0.9999之间。平均回收率为74.6%～113.4%,相对标准偏差在2.4%～8.6%之间。本方法操作简便、快速、可靠,检测限和加标回收率均能满足无糖食品中糖醇的定量分析要求。     

固相萃取-高效液相色谱法测定大鼠尿样中调环酸钙

建立了大鼠尿样中调环酸钙的高效液相色谱(HPLC)测定方法。样品经Waters OasisMAX 3cc固相萃取小柱净化,Poroshell 120EC-C18色谱柱(100×4.6 mm,2.7μm)分离,甲醇-0.01%甲酸水溶液梯度洗脱,流速为0.4mL/min,检测波长275nm。研究结果表明,尿样中调环酸钙的质量浓度在0.20~5.00μg/mL范围内线性关系良好(R2=0.999),检出限为0.06μg/mL,定量限为0.19μg/mL,回收率在96.41%~104.94%之间。日内相对标准偏差(RSD)为2.14%~3.89%,日间RSD为5.01%~7.58%。该方法前处理简单可行,适合尿样中调环酸钙的测定。     

液相色谱法对牛、猪肌肉和肾脏中头孢噻呋残留量的测定研究

采用高效液相色谱法测定牛、猪肌肉和肾脏中头孢噻呋相关残留量.样品经二硫赤藓糖醇溶液提取,碘乙酰胺衍生,固相萃取柱(C18、SAX和SCX)净化,C18柱色谱分离,以乙腈-水(体积比15:85)含0.1%三氟乙酸作流动相等梯度洗脱,266 nm紫外检测.头孢噻呋残留量在0.016～1.28 mg/L范围内与峰面积呈良好线性,相关系数r0.999 9.样品添加浓度在200～8 000μg/kg的回收率为90%～91%,相对标准偏差为1.8%～3.5%.本方法的检出限(信噪比S/N=3)为50μg/kg.     

Robust and sensitive high-performance liquid chromatographic-UV detection technique for the determination of tigecycline in rabbit plasma

An isocratic HPLC method with detection at 248 nm was developed and fully validated for the determination of tigecycline in rabbit plasma. Minocycline was used as an internal standard. A Hypersil BDS RP-C18 column (250 x 4.6 mm, 5 microm particle size) was used with the mobile phase phosphate buffer (pH 7.10, 0.070 M)-acetonitrile (76 + 24, v/v) at a flow rate of 1.0 mL/min. The elution time of tigecycline and minocycline was approximately 8.1 and 9.9 min, respectively. Calibration curves of tigecycline were linear in the concentration range of 0.021-3.15 microg/mL in plasma. The LOD and LOQ in plasma were estimated as 7 and 21 ng/mL, respectively. The intraday and interday precision values of the method were in the range of 5.0-7.1 and 5.6-9.1%, while the corresponding accuracy values were in the ranges of 92.8-111.1 and 97.6-102.3%, respectively. At the LOQ, the intraday precision was 18.7%, while intraday and interday accuracy values were 97.3 and 98.0%, respectively. Robustness of the proposed method was studied using a Plackett-Burman experimental design. A pharmacokinetic profile is presented for confirmation of the applicability of the method to pharmacokinetic studies.     

A simple method for simultaneous determination of basic dyes encountered in food preparations by reversed-phase HPLC

The present method utilizes a simple pretreatment step, cleanup on polyamide SPE cartridges, and HPLC resolution on reversed-phase C18 for the detection of the three basic nonpermitted dyes encountered in food matrixes. Polyamide cartridges were chosen because both acidic and basic dyes can be cleaned up due to their amphoteric nature. Analysis was performed on a reversed-phase C18 micro-Bondapak column using the isocratic mixture of acetonitrile-sodium acetate with a flow rate of 1.5 mL/min and a programmable lambda(max) specific visible detection to monitor colors, achieving higher sensitivity and expanded scope to test multicolor blends. All the colors showed linearity with the regression coefficient, from 0.9983 to 0.9995. The LOD and LOQ ranged between 0.107 and 0.754 mg/L and 0.371 and 2.27 mg/L or mg/kg, respectively. The intraday and interday precision gave good RSDs, and percentage recoveries in different food matrixes ranged from 75 to 96.5%. The study demonstrates that the use of a combination of a simple SPE cleanup and HPLC resolution with UV-Vis end point detection was successful in screening the presence of these three basic nonpermitted dyes individually or in blend, in a variety of food matrixes.     

分子印迹膜萃取结合高效液相色谱-串联质谱法快速检测牛奶中的痕量环丙沙星残留

以聚偏氟乙烯膜为载体，恩诺沙星为伪模板分子，甲基丙烯酸为功能单体，乙二醇二甲基丙烯酸酯为交联剂，在氯仿-甲醇混合体系中制备恩诺沙星分子印迹膜（MIM），并将其作为分子印迹膜萃取（MIME）材料萃取牛奶样品中的环丙沙星，结合高效液相色谱-串联质谱（HPLC-MS/MS），快速检测牛奶中痕量环丙沙星残留。环丙沙星在0.1~200 μg/L范围内线性关系良好，相关系数为0.9996，检出限（S/N=3）和定量限（S/N=10）分别为0.02和0.10 μg/L。日间和日内精密度的相对标准偏差（RSD）在3.3%~7.9%之间。将开发的MIME-HPLC-MS/MS方法用于实际牛奶样品中环丙沙星加标回收率的检测，回收率在92.6%~119.1%之间。结果表明该方法前处理简单快速灵敏，检测准确度高，可用于牛奶样品中痕量环丙沙星残留的快速检测。     

Rapid method for the determination of vitamins A and E in foods using ultra-high-performance liquid chromatography

A rapid and novel ultra-HPLC (u-HPLC) method for the determination of vitamins A (retinol) and E (alpha-, gamma-, and delta-tocopherol) in foods was validated in terms of its precision, accuracy, and linearity. The u-HPLC separation was performed on an RP C18 column (particle size 2 microm, id 2 mm, and length 75 mm), followed by fluorescence detection. The recovery of retinol was more than 84.58%; the LOD and LOQ of the u-HPLC analysis were 0.015 and 0.045 mg/kg, respectively. The intraday and interday precision was less than 9.12%. The recoveries of alpha-, gamma-, and delta-tocopherol were more than 81.37%; the LOD and the LOQ were 0.014, 0.002, and 0.001 mg/kg and 0.042, 0.005, and 0.004 mg/kg, respectively. All calibration curves had good linearity (r2 = 0.99) within the test ranges. The novel, rapid method coupled to u-HPLC can provide significant improvements in the speed, sensitivity, and resolution compared with a conventional HPLC method.     

Quantitative evaluation of benzene, toluene, and xylene in the larvae of Drosophila melanogaster by solid-phase microextraction/gas chromatography/mass spectrometry for potential use in toxicological studies

A simple, rapid, and solvent-free method for quantitative determination of benzene, toluene, and Xylene in exposed Drosophila larvae was developed using headspace solid-phase microextraction (HS-SPME) coupled to GC/MS. Larvae fed on standard Drosophila food mixed with benzene, toluene, and Xylene for 48 h were homogenized in Milli-Q water. Extraction of benzene, toluene, and Xylene was performed at 65 degrees C for 30 min on the SPME fiber (silica-fused). Subsequently, the fiber was desorbed in the GC injection port, followed by GC/MS analysis in the selected-ion monitoring mode. An external calibration curve was used for the quantification of benzene, toluene, and Xylene in the exposed organism. Recoveries were in the range of 78-82% (intraday) and 76-81% (interday) in larvae, and 91-96% (intraday) and 87-92% (interday) in the diet. LOD with an S/N of 3:1 and LOQ with an S/N of 10:1 were in the range of 0.01-0.023 and 0.034-0.077 microg/L, respectively. Percent RSD values for benzene, toluene, and Xylene were in the range of 0.50-0.81 (intraday) and 0.89-1.23 (interday) for retention time, and 2.16--3.85 (intraday) and 2.99-4.95 (interday) for peak concentration, showing good repeatability. This method was sensitive enough to quantitate benzene, toluene, and Xylene in small exposed organisms like Drosophila larvae. The SPME/GC/MS method developed may have wider applications in various in vivo toxicological studies.     

Determination of Fatty Acid Methyl Esters in Biodiesel Produced from Yellow Horn Oil by LC

A simple and accurate HPLC method with refractive index detection was developed to determine the main fatty acid methyl esters in biodiesel produced from yellow horn oil. Methyl linoleate, methyl linolenate, methyl arachidate, methyl stearate, methyl palmitate and methyl oleate were separated on a HIQ SIL C18W column using methanol as mobile phase. The method has good repeatability and precision, the intraday and interday RSD for both retention time and peak area was less than 3.2%. The LOD (S/N = 3) and LOQ (S/N = 9) were less than 0.004 and 0.015 mg mL⁻¹, respectively.     

Rapid method for the determination of capsaicin and dihydrocapsaicin in Gochujang using ultra-high-performance liquid chromatography

A sensitive and specific heating block method coupled with ultra-HPLC (u-HPLC) was developed for the analysis of capsaicin in Gochujang and validated by comparing with a conventional HPLC (AOAC Method 995.03). The method validation parameters yielded good results, including linearity, precision, accuracy, and recovery. The u-HPLC separation was performed on a reversed C18 column (50 x 2 mm id, particle size 2 microm), followed by fluorescence detection (excitation 280 nm, emission 325 nm). Methanol was used as the extracting solvent, and the amount of sample taken was approximately 0.2 g; the optimum amount of extraction solvent and extraction time were 15 mL and 1 h, respectively. The recovery of capsaicin in Gochujang was more than 93%, and the LOD and LOQ of the u-HPLC analysis were 0.05 and 0.16 microg/g for capsaicin and 0.05 and 0.16 microg/g for dihydrocapsaicin. The calibration graphs for capsaicin and dihydrocapsaicin were linear from 0.2 to 10.0 microg/mL for u-HPLC. The interday and intraday precisions (RSD values) were < 6.27%.     

Development and validation of a high performance liquid chromatography-diode array detection method for the determination of aging markers in tequila

A solid-phase extraction procedure followed by analysis by high performance liquid chromatography (HPLC) with UV-vis photodiode array detection (DAD) is proposed to simultaneously determine 11 aging markers in tequila. The method showed good intraday (n=5) and interday (n=3) precision, RSD<1.6% in both cases, for each of the identified compounds. The calibration curves were linear at the tested ranges (R(2)>0.999). Good recoveries (84.2-108.5%) were obtained for 10 of the 11 compounds studied; and the LOD and LOQ ranged from 0.62 to 4.09 microg/mL and 1.9-12.4 microg/mL, respectively. The proposed methodology was applied to a set of 15 authentic tequila samples grouped by aging state (blanco, reposado and a?ejo). An ANOVA analysis combined with discriminant analysis with stepwise backward variable selection was used to differentiate between the various aging groups based on their oak related compounds content.     

Development of a novel direct bioautography-thin-layer chromatography test: optimization of growth conditions for gram-negative bacteria, Escherichia coli

With the aim of developing a TLC-direct bioautography assay using Escherichia coli as test bacteria, various parameters influencing the viability of microorganisms on TLC plates were examined and checked for flumequine standards. The optimal times for preincubation and incubation of bacterial broth were 20 h at 37 degrees C and 2 h at 37 degrees C, respectively. The optimal viscosity of the broth was obtained for 0.05% agarose solution in Mueller-Hinton broth. Various incubation times of the seeded TLC plates were also tested (5 h proved to be optimal). After incubation, the plates were sprayed with 0.2% aqueous [3-(4,5-dimethyldiazol-2-yl)-2,5 diphenyltetrazolium bromide] (MTT) solution and incubated for 0.5 h at 37 degrees C. The precision of the method was evaluated by the repeatability (intraday assay) and intermediate precision (interday assay). The regression coefficients were 0.9977 and 0.9968, respectively, for intraday and interday curves. The calibration curves show good linearity in the range of 0.005-0.50 microg (0.5-50.0 microg/mL). The established LOD of flumequine equaled 0.5 microg/mL, i.e., 5 ng flumequine in the spot. The developed direct bioautography test significantly enhances the sensitivity of the TLC method.     

柱前在线衍生-HPLC内标法快速测定脑蛋白水解物注射液中的氨基酸

建立了利用高效液相色谱仪快速测定脑蛋白水解物注射液中氨基酸含量的方法.样品处理采用先提取后水解转化的方法,色谱分离使用反相C18分析柱二元高压梯度洗脱;使用二极管阵列检测器检测,波长为260 nm;分析时间为14 min.各氨基酸在4.5-900μmol/L范围内线性关系良好,相关系数为0.998 7-0.9999;检...