乳粉中维生素K1高效液相色谱测定方法的改进

通过改进流动相和样品处理方法，确定了最佳的流动相配比，缩短了分析时间（Rt=11min左右），降低了检出限（0．02μg／lOOg），维生素K1的最小检出浓度达到0．20μg／100g．     

Green and Efficient Determination of Fluoroquinolone Residues in Edible Green Fruits and Leafy Vegetables by Ultrasound-Assisted Extraction Followed by HPLC-MS/MS

In this work, a simple, quick and efficient analytical method for determination of human and veterinary fluoroquinolone antimicrobial residues in lettuce, cucumber and spinach is developed. The procedure entails a 6 min ultrasound-assisted extraction (UAE, 3 × 2 min) in an alkaline (2% v/v NH₃) aqueous solution containing Mg²⁺ ions (3 × 6 mL), with no need for organic solvents. The extract is submitted to cleanup on the HLB™ cartridge and the fluoroquinolones are separated and quantified by HPLC-MS/MS in a 10 min chromatographic run, using a small amount of acetonitrile in the mobile phase. The method, entirely developed in real matrices, is validated according to the updated analytical guidelines and provided suitable recoveries in the range of 67–116% and precision (RSD ≤ 20%, n = 3) at different concentrations (15, 70 and 150 ng g⁻¹), with method quantification limits of 2–10 ng g⁻¹. Fluoroquinolones were detected and quantified at concentrations from few to hundreds of nanograms per gram in vegetables from supermarkets, demonstrating the applicability of the method for monitoring residues of these pharmaceuticals.     

高效液相色谱法测定强化奶及食品中维生素D含量

介绍用反相高效液相色谱法（ＨＰＬＣ）测定食品中ＶＤ含量,样品经皂化、正己烷提取、正相ＨＰＬＣ净化,用反相ＨＰＬＣ定量分析。回收率为９４．８８％～９９．７０％,批内和批间ＣＶ分别为１．６２％和２．１２％。分析了奶粉、要素膳、肉松、儿保饮料等８种食品中ＶＤ含量,亦可用于各种食品中ＶＤ分析。     

应用SPE柱净化HPLC/UV法测定乳制品及其原料中的硫氰酸盐

采用SPE柱净化、高效液相反相离子对色谱分离、紫外检测器(HPLC/UV)测定乳制品及其原料中的硫氰酸盐。试样经乙酸沉淀蛋白、Oasis WAX SPE柱净化和浓缩,以甲醇和磷酸盐缓冲液加离子对试剂为流动相,经Symmetry C18色谱柱分离,在231 nm波长处进行检测,外标法定量。结果表明,硫氰酸盐浓度在0.2～50 mg/L范围内线性良好,相关系数大于0.999,方法检出限为0.05 mg/kg,定量下限为0.15 mg/kg,在加标量为1、5、25 mg/kg时的回收率为77%～104%。该方法重现性好、检测时间短,灵敏度高,为乳制品及其原料中硫氰酸盐的定量检测提供了较为理想的方法。     

离子色谱法快速测定牛奶中SCN~–

建立了离子色谱快速测定牛奶中SCN–的方法。采用东曹IC–2010型号离子色谱仪及TSKgel Super IC–Anion HS型阴离子快速分离柱;淋洗液为5.0 mmol/L Na2CO3溶液,流量为1.5 m L/min,柱温为40℃,进样体积为20μL,样品经乙腈去蛋白,经TOYOPAK ODS小柱除掉脂肪后,经IC–2010自动进样器自动稀释2倍后进样分析。硫氰酸根测定结果的相对标准偏差为0.94%(n=5),加标回收率为97.0%~102.8%。该方法可用于鲜奶中硫氰酸根的检测。     

高效液相色谱法测定强化食品中维生素C的含量

建立了强化食品(饮料、奶粉、含乳饮料、大米、果泥及果冻)中维生素C含量的高效液相色谱检测方法。优化了样品处理方法,在水浴控温和避光条件下处理样品,避免维生素C被氧化。选用Tech Mate C18–ST(250 mm×4.6 mm,5μm)反相色谱柱,以0.05 mol/L磷酸二氢钾缓冲溶液(p H 3)为流动相,流量为1.0m L/min,检测器为光电二极管阵列检测器,检测波长为266 nm。线性范围为0.2~100μg/m L,相关系数为0.999 6,果泥中维生素C的定量限为20 mg/kg,其它为100 mg/kg,加标回收率为82.2%~107%,测定结果的相对标准偏差为1.23%~6.86%(n=8)。该方法简单快速,其灵敏度、准确度和精密度均能满足强化食品中维生素C的检测要求。     

ASE-HPLC检测某型号球形发射药中的叠氮硝胺、硝化甘油、Ⅱ号中定剂含量的研究

采用快速溶剂萃取(ASE)技术和高效液相色谱法测定某球形药中叠氮硝胺(DIANP)、硝化甘油(NG)和II号中定剂(C2)的含量.ASE提取条件:二氯甲烷做萃取溶剂,萃取温度100℃,静态萃取10 min,萃取2次.HPLC测定条件:YWG C18柱(150×4.6 mm,10μm),以甲醇和水作为流动相,梯度洗脱,流速1 mL/min,检测波长210nm.测定结果表明DIANP、NG、C2平均回收率分别为99.6%、100.3%、99.4%,RSD分别为0.7%、0.8%、0.9%(n=5),检出限分别为2.1、1.5和0.2 mg/L,线性范围分别为0.02~0.98 g/L,0.03~1.38 g/L,0.002~0.124g/L.用此方法共检测某批球形发射药样品5份,检测结果与滴析-HPLC法检测结果相当.     

HPLC法测定杜仲中维生素K1

为检测杜仲中维生素K1含量,采用了特异性强、分离效果好的高效液相色谱(HPLC)法,将样品经丙酮、石油醚提取,用失活磷酸盐处理过的氧化铝进行柱色谱净化处理,用极性不同的洗脱液将维生素K1从样品中分离出来,收集V(石油醚) V(乙醚)=97 3洗脱组分,浓缩定容,用C18色谱柱对维生素K1进行定性定量分析,流动相为V(甲醇) V(正己烷)=75 25,紫外检测波长为248 nm。结果表明,在流量为1.5 mL/min的条件下,维生素K1的保留时间为(2.18±0.1)min,r为0.999 3,回收率87.67%~95.12%,杜仲中的维生素K1含量为12.404 3μg/g。     

高效液相色谱法同时测定牛奶中的香兰素与乙基香兰素

建立了同时测定牛奶中香兰素与乙基香兰素含量的高效液相色谱法。首先对样品进行超声提取,再经酸沉淀蛋白质后进行分析。采用Ultimate XB–C18色谱柱,流动相为甲醇–0.01 mol/L磷酸溶液(体积比为30∶70),流速为1.0 mL/min,检测波长为276 nm。香兰素与乙基香兰素在0.5~10μg/mL范围内线性良好,检出限分别为5.68μg/L和12.8μg/L,平均加标回收率分别为99.8%,98.4%。该方法简便,准确度高,重现性好,可用于牛奶中香兰素与乙基香兰素的日常检测。     

高效液相色谱荧光检测法快速测定天然生育酚中痕量苯并[a]芘

建立了一种快速、新颖的高效液相色谱荧光检测法测定天然生育酚中痕量苯并[a]芘.天然生育酚样品经中性氧化铝柱色谱富集和净化后在 XDB-C,18反相柱上,采用水-乙腈(体积比20比80)为流动相进行分离,采用荧光检测器进行检测,其激发波长为 260 nm,发射波长为 408 nm.苯并[a]芘的定量下限为 0.50 ng·g-1.加标回收率大于 77.9%.分析了 3 个不同试样,测定结果的相对标准偏差在 3.0%～10.6%之间.     

高效液相色谱法同时测定强化牛奶中的维生素A和D_2

A reversed-phase high performance liquid chromatographic method for the simultaneous determination ofvitamin A and D_2 in fortified milk has been developed. A couple of serially connected columns with μ-Bonda-pak C_(18)(300 × 3. 9mm, 10μm)and Novapak C_(18)(150 × 3. 9mm, 4μm)and methanol/water(96/4)mobile phasewere used. Vitamin A and D_2 were detected at wavelengths of 325nm and 265nm, respectively. By usingsaponification procedure, the recoveries of vitamin A and D_2 were in the range of 90～110%.     

Simple Multiresidue Determination of Fluoroquinolones in Bovine Milk by Liquid Chromatography with Fluorescence Detection

Abstract

A simple and sensitive method for the simultaneous determination of five fluoroquinolones (ciprofloxacin, enrofloxacin, danofloxacin, difloxacin, and sarafloxacin) in bovine milk was developed. Protein precipitation from milk samples was achieved by the addition of acetonitrile and o‐phosphoric acid. Acetonitrile was removed with dichloromethane, leaving the fluoroquinolones in the acid aqueous extract. The aqueous extract was analyzed by liquid chromatography with fluorescence detection (LC–FD). The mobile phase was composed of acetonitrile and 10 mM citrate buffer solution of pH 4.5, with an initial composition of acetonitrile‐water (12∶88, v/v) and using linear gradient elution. Norfloxacin was used as an internal standard. The limits of detection found ranged from 1 to 6 ng · mL^?1 and were below the maximum residue limits (MRLs) established by the European Union. The proposed method was applied to the determination of these compounds in different bovine milk samples. Method validation was carried out by a recovery assay.     

固相萃取-高效液相色谱法同时测定牛奶中残留的9种磺胺类药物

建立了同时测定牛奶中残留的9种磺胺类药物的固相萃取-高效液相色谱分析方法。牛奶样品经磷酸盐缓冲液稀释后高速离心去除脂肪,过C18小柱,用水淋洗,甲醇洗脱,洗脱液经氮气吹干后用乙酸乙酯溶解,并过氨基固相萃取小柱净化,用正己烷及水淋洗,以甲醇-乙腈-水（含1%乙酸）(体积比为1∶1∶8)洗脱,洗脱液用于高效液相色谱分析。采用Inertsil ODS-3 C18柱分离,以水-乙酸和甲醇-乙腈为流动相进行梯度洗脱,二极管阵列检测器检测,外标法定量。9种磺胺类药物标准曲线的线性回归系数均在 0.9999 以上,线性范围为25～5000 μg/L,检出限为1.7～2.8 μg/L,定量限为5.7～9.2 μg/L。在10,20,40 μg/L 添加水平下的添加回收率为72.1%~88.3%,相对标准偏差为2.3%～5.0%。该方法具有快速、灵敏的特点,符合现行兽药残留分析的要求。     

超高效液相色谱串联质谱法测定婴儿奶粉中的维生素B_(12)

建立了超高效液相色谱串联质谱法测定婴儿奶粉中维生素B12的方法。采用三氯乙酸沉淀蛋白质,HLB固相小柱吸附净化提取液中的维生素B12,以50%的甲醇洗脱,吹去甲醇后定容测定,色谱柱为ACQUTITY UPLC BEH C18柱,以甲醇–10 mmol/L乙酸铵水溶液为流动相梯度洗脱,MRM模式,定量离子为m/z 678.3/147.2。在优化条件下,线性范围为0.5~200μg/L,相关系数(r)为0.999 3,检出限为0.3μg/kg,回收率为88.3%~92.9%,测定结果的相对标准偏差小于5%(n=6)。方法具有样品处理简单、灵敏度高、重现性好、分析时间短等优点,可以作为实验室常规测定婴幼儿奶粉中维生素B12的方法。     

亲水色谱-串联质谱法对牛奶与奶粉中三聚氰胺及其衍生物含量的测定

建立了牛奶和奶粉中三聚氰胺及其3种衍生物（三聚氰酸、三聚氰酸一酰胺、三聚氰酸二酰胺）的亲水色谱-串联质谱检测方法（HILIC-MS/MS）。牛奶样品直接用乙腈超声波提取;奶粉样品先用水溶解后再加乙腈超声波提取,高速离心后以乙腈-水为流动相,采用亲水作用色谱柱分离这4种化合物,在电喷雾正、负电离切换多反应监测模式下进行定性与定量分析,三聚氰酸一酰胺与三聚氰酸二酰胺含量在50～10000μg/kg之间、三聚氰胺与三聚氰酸在25～5000μg/kg之间,均获得良好的线性。方法检出限（LOD）为5～20μg/kg,定量下限（LOQ）为50～100μg/kg,3个添加水平的平均回收率为81%～97%。该方法简便、快速、准确,可满足牛奶及奶粉中三聚氰胺、三聚氰酸、三聚氰酸一酰胺、三聚氰酸二酰胺测定的需要。     

维生素D包合物中维生素D的高效液相色谱测定

Vitamin D in the VDHCD inclusion complex was determined by HPLC on a Resolve silica column usingamobile phase of n-hexane:n-amylalcohol=95:5(V/V)and UV detection at 254 nm.The quantitative de-termination was performed with dimethyl phthalate as the internal standard.     

测定牛奶中5种青霉素残留量的高效液相色谱柱前衍生法

样品采用乙腈直接提取,离心分离及固相（Ｃ１８柱）净化方式,经衍生后,用液相色谱紫外检测器测定牛奶中５种青霉素残留,方法最小检测质量 度０．００５ｍｇ／Ｌ,回收率范围在６８．９％－１０１．３％之间,相对标准偏差为３．２１％－６．１８％。     

Validation Method for the Determination of Sulfonamide Residues in Bovine Milk by HPLC

A simple, rapid, sensitive and reliable high-performance liquid chromatographic method for the simultaneous determination of eight sulfonamides (SAs) in bovine milk was developed (sulfadiazine, sulfathiazole, sulfamethazine, sulfamethoxypyridazine, sufamonomethoxine, sulfamethoxazole, sulfadimethoxine and sulfaquinoxaline) in bovine milk was developed. Samples were prepared by extraction with ethyl acetate and cleaning-up with an anion solid-phase extraction (SPE) column. Analytical separation was performed on an Inertsil ODS-3 column with photodiode-array detection at 270 nm under gradient condition. The whole procedure was evaluated according to the European Commission Decision 2002/657/EC. Specificity, decision limit (CCα), detection capacity (CCβ), trueness and precision were determined during the validation process. It was found that the analytes were isolated from spiked samples with good recoveries between 70.5 and 89.0%. The used analytical conditions allow to successively separating all the tested sulfonamides with good limit of detection between 0.8 and 1.5 μg L⁻¹.     

Determination of Tetracyclines in Milk by Graphene-Based Solid-Phase Extraction and High-Performance Liquid Chromatography

A graphene-based solid-phase extraction (SPE) column was prepared for the isolation of tetracyclines from milk followed by determination by high-performance liquid chromatography. Graphene provided better separation for tetracyclines than amine-modified graphene and carboxyl-modified graphene. The optimized graphene-based SPE column showed high absorption capacities (greater than 4,660?ng) and high recoveries (exceeding 92%) for tetracycline, oxytetracycline, chlortetracycline, and doxycycline and was successfully reused at least fifty times. The limits of detection in milk were from 10 to 20?ng/mL, with recoveries between 82.3 and 103.6%. Furthermore, the system showed superior performance than two commercial SPE cartridges with respect to recovery, purification, and reusability. Therefore, this approach is suitable for the determination of tetracyclines in milk.     

Simultaneous Determination of Seven Active Compounds in Radix Salviae Miltiorrhizae by Temperature-Controlled Ultrasound-Assisted Extraction and HPLC

A simple and effective high-performance liquid chromatographic (HPLC) method has been developed for simultaneous quantification of three phenolic acids (3,4-dihydroxyphenyllactic acid (Chinese name danshensu), protocatechuic aldehyde, and salvianolic acid B) and four diterpenes (dihydrotanshinone I, cryptotanshinone, tanshinone I, and tanshinone II_A) in radix salviae miltiorrhizae. Chromatography was performed on a 250 mm × 4.6 mm i.d., 5-μm particle size, C₁₈ column. The mobile phase was a linear gradient prepared from 0.1% (v/v) aqueous formic acid and acetonitrile at a flow-rate of 1.0 mL min⁻¹. All the target components were well separated with high resolution and without interference. Good linearity (R ² > 0.999) was observed over the concentration ranges investigated, and intra-day and inter-day precision were high. Temperature-controlled ultrasound-assisted extraction was used to prevent hydrolysis of thermally unstable components during the sample-extraction procedure, and the extraction conditions were carefully optimized. Recovery of the seven components was from 98.45 to 100.63% and relative standard deviations were always <1.5%. The validated method was successfully used for simultaneous quantification of the three phenolic acids and the four diterpenes in radix salviae miltiorrhizae of different geographic origins.