奶粉中β-胡萝卜素的高效液相色谱法测定

使用Inertsil SIL-100硅胶柱，以正己烷等为流动相的正相液相色谱方法分析乳粉中的β-胡萝卜素收到了较好的效果．该方法的检出限、重现性、回收率和线性范围分别为：0．220μg／mL，1．88％，90．2％～95．1％和2．280～456．000μg／mL．关于采用正相液相色谱法分析β-胡萝卜素的方法未见报到．该方法具有快速，灵敏度高的特点，保留时间仅为3min左右，并大大地缩短了分析时间，提高了效率．     

蔬菜叶片中叶绿素a和叶绿素b的一阶导数分光光度法测定

本文提出用一阶异数分光光度法同时测定蔬菜叶片中叶绿素ａ和叶绿素ｂ的含量。讨论了同时存在于蔬菜叶片中的类胡萝卜素对两者测定的影响，并提出用适当浓度的类胡萝卜素丙酮溶液作为参比溶液，用以消除类胡萝卜素对叶绿素测定的影响。     

蔬菜叶片中叶绿素a和叶绿素b的阶导数分光光度法测定

本文提出用一阶导数分光光度法同时测定蔬菜叶片中叶绿素ａ和叶绿素ｂ的含量。讨论了同时存在于蔬菜叶片中的类胡萝卜素对两者测定的影响，并提出用适当浓度的类胡萝卜素丙酮溶液作为参比溶液，用以消除类胡萝卜素对叶绿素测定的影响。     

测定雨生红球藻中虾青素及其它色素含量的高效液相色谱法

建立了一种分离和测定雨生红球藻中虾青素和其它色素的反相高效液相色谱法 ;含有雨生红球藻细胞的培养液经离心分离 ,匀浆破碎 ,用甲醇 -二氯甲烷 (体积比3∶1)提取色素 ,提取液用HPLC分离测定 ;分析柱为Nova_PakC18(300mm×3.9mmID ,5μm)柱 ,流动相为水、甲醇和丙酮 ,流速1.0mL/min ,用二极管阵列检测器在250～700nm波长范围扫描 ,在476nm处进行检测 ;虾青素、多种类胡萝卜素和叶绿素在30min内得到较好分离 ,其中游离虾青素、斑蝥黄质和 β_胡萝卜素的检出限分别为3.56、1.36和29.4μg/L,这3种类胡萝卜素分别在质量浓度为1.99～31.7mg/L、2.44～39.0mg/L、2.25～36.0mg/L范围内与峰面积线性关系良好 ,相关系数分别为0.9993、0.9987和0.9778;该法的精密度 (RSD为0.09 %～2.97% )和回收率(96%～102 % )均符合方法学要求 ,可以用于研究和测定雨生红球藻中虾青素和其它色素的含量     

气相色谱-电子捕获检测器同时测定茶叶中有机氯及拟除虫菊酯类农药残留

在超声波辅助下,以正己烷-二氯甲烷（1：1,V／V）混合溶剂提取样品,提取液用弗罗里硅土和中性氧化铝混合柱净化,用气相色谱-电子捕获检测器（GC-ECD）同时测定茶叶中18种有机氯和9种拟除虫菊酯类农药残留。有机氯农药在0.001-0.2μg／mL,拟除虫菊酯类农药在0.005-1.0μg／mL范围内线性良好。有机氯农药在0.04、0.01μg／mL两个添加水平的回收率分别为89.5％-113.2％和80.0％-112.7％,相对标准偏差分别为3.82％-9.64％和5.32％-13.8％。拟除虫菊酯在0.2、O.05μg／mL两个添加水平的回收率分别为97.5％-129.6％和87.3％-110.2％,相对标准偏差分别为3.78％-10.72％和3.02％-13.84％。本方法快速、灵敏、准确、可靠,用于江西茶叶样品中有机农药残留测定,获得较好结果。     

高效液相色谱-三重四极杆质谱同时测定与筛查海洋浮游藻类中的5种色素

对海洋藻类色素的高效液相色谱-三重四极杆质谱（HPLC-QqQ-MS）分析方法的有效性进行了验证。该方法采用C₁₆氨基色谱柱为固定相,以甲醇、乙腈和乙酸铵为流动相,在选择反应监测模式下对叶绿素a、叶绿素b、 β,β -胡萝卜素、叶黄素和岩藻黄素的含量进行了测定。结果表明,5种色素标准品的线性关系良好,相关系数（r²）均高于0.996,回收率在82.77%~99.83%之间,日内和日间精密度的相对标准偏差（RSD）均小于5%（n=5）;方法的检出限（LOD）在0.02~0.16 μg/L之间,定量限（LOQ）在0.06~0.54 μg/L之间。利用该方法对11种藻类中5种色素的含量进行分析,比较了赤潮异弯藻、卡罗藻、微小原甲藻、微拟球藻、蛋白核小球藻、颗石藻、定鞭金藻、中肋骨条藻、威氏海链藻和假微型海链藻之间的物种色素分布情况。该方法具有简单、灵敏度高、重复性好、回收率高等优点,适合藻类色素分析,为进行藻类生物量计算提供了分析手段。     

反相高效液相色谱法同时测定番茄中5种类胡萝卜素

用反相高效液相色谱法同时测定了番茄中的α－胡萝卜素、β－胡萝卜素、γ－胡萝卜素、番茄红素及斑蝥黄素。采用１１（Ｖ／Ｖ）丙酮－石油醚混合液直接提取,提取液减压蒸干后,用甲醇溶解,经μ－ＢｏｎｄａｐａｋＣ１８色谱柱,以乙腈－二氯甲烷－甲醇（８５１０５）为流动相,在４５０ｎｍ下进行检测,其保留时间依次为１５．２５,１６．１２,１２．８７,１０．３８和５．３７ｍｉｎ,最小检出限分别为０．２５,０．２２,０．１８,０．１４和０．０５ｍｇ／Ｌ。     

叶黄素的几类降解反应研究

类胡萝卜素是一大级一泛存在于动植物体内的四储类化合物,它们不仅颜色鲜艳,也是一类重要香味物质的前体。在Ｍ的烟０－Ｉ中已有１８种类型的胡萝卜素被分离和日表征。其中卜胡萝卜素和叶黄素是主要成分ｌ‘］。烟叶采收后,类胡萝卜素经生物降解,会生成一系列有挥发性芳香化合物,它什对卷烟的吸味、品质有很大的影响Ｉ２］。本文设计了四种化学方法,对叶黄素进行氧化降解,产物用ＧＣ／ＭＳ进行检测。结果表明,在适当条件下对叶黄素进行化学法氧化降解,可以得到如：氢化异佛尔酮、环氧紫萝兰酮、二氢弥猴桃内＠纺ｏ茶香螺酮等有重要…     

高效液相色谱法测定栅藻中5种类胡萝卜素的含量

建立了栅藻中虾青素、叶黄素、玉米黄质、角黄素和β-胡萝卜素5种类胡萝卜素的C30-反相高效液相色谱测定方法。冻干的藻粉经二甲基亚砜、二氯甲烷∶甲醇(25∶75,V/V)混合溶剂超声提取后,经0.107mol/L NaOH-甲醇溶液4℃下黑暗冷皂化12h,采用YMC-carotenoid C30色谱柱(250×4.6mm,5μm),以甲醇、甲基叔丁基醚、水组成的流动相梯度洗脱,紫外检测器450nm检测。在优化实验条件下,5种色素可以很好地从藻粉中提取出来并且转化为游离的类胡萝卜素,并且在不同浓度下其峰强度和质量浓度呈良好的线性。虾青素、叶黄素、玉米黄质、角黄素和β-胡萝卜素的平均回收率范围为101%~107%,平均相对标准偏差范围为0.49%~2.78%,检出限范围为0.05~0.3μg/mL。该方法操作简单准确、可靠,可同时定量分析栅藻中上述5种类胡萝卜素的含量。     

反相高效液相色谱法同时测定保健品中的四种类胡萝卜素

建立了不同剂型保健品中类胡萝卜素的提取方法和同时测定保健品中4种类胡萝卜素含量的高效液相色谱分析方法。采用DiamonsilTM C18色谱柱(250 mm×4.6 mm i.d.,5 μm),以乙腈和乙酸乙酯为流动相进行梯度洗脱,洗脱程序：先以100%乙腈洗脱15 min,然后乙酸乙酯的含量在10 min 内从0增加到100%,再以100%乙腈洗脱5 min;流速1 mL/min;采用二极管阵列检测器检测,检测波长为450 nm。以外标法定量,番茄红素、叶黄素、玉米黄素、β-胡萝卜素4种组分的线性关系良好,相关系数为0.9994～0.9997,检测限为0.4～0.5g/L。片剂样品、粉状样品、油状样品的加标回收率分别为95.3%～98.7%,93.7%～98.8%,97.1%～99.2%,相对标准偏差（RSD）分别为0.89%～2.0%,0.89%～2.8%,0.42%～1.2%。该法简便、快速、准确,是保健品中多种类胡萝卜素定量测定的可靠方法之一。     

High-performance liquid chromatography for the characterization of carotenoids in the new sweet orange (Earlygold) grown in Florida, USA

High-performance liquid chromatography with photodiode array detection was developed for the separation and identification of carotenoids from a new sweet orange, Earlygold. Carotenoid pigments were extracted using hexane-acetone-ethanol and saponified using 10% methanolic potassium hydroxide. More than 25 carotenoid pigments were separated within 40 min using a ternary gradient (acetonitrile-methanol, methyl tert-butyl ether and water) elution on a C30 reversed-phase column. The carotenoid pattern of Earlygold was generally similar to the early season Hamlin but with some quantitative differences, especially with violaxanthin. Major carotenoids including violaxanthin, lutein, beta-cryptoxanthin, antheraxanthin, luteoxanthin, zeaxanthin, beta-carotene, and alpha-carotene were identified based on on-line spectral data obtained by a photodiode array detector, and comparison to the spectra of the standards and reported values. A numerical notation, the ratio of the peak heights between absorption bands, was also calculated to compare to the literature values.     

Isolation of carotenoids from plant materials and dietary supplements by high-speed counter-current chromatography

Methods for the isolation of lipophilic pigments from crude extracts of plant materials (spinach and sweet corn) by high-speed counter-current chromatography (HSCCC) were developed. Particular attention was given to (all-E)-lutein and (all-E)-zeaxanthin. However, the concomitant pigments neoxanthin, violaxanthin and beta-carotene as well as chlorophylls a and b were also considered. Furthermore, for the first time dietary supplements containing lutein and zeaxanthin were also used as a source for the recovery of carotenoids. Due to their simple matrix (oily excipient in soft gelatine capsules), sample preparation was facilitated and consumption of solvents was minimized. The carotenoids were characterized by 1H NMR spectroscopy, by LC/APcI-MS in the positive ionization mode, and by UV-vis spectroscopy.Data showed that the target compounds were of high purity (90 - 93%). Lutein and zeaxanthin may be used as reference substances for analytical purposes.     

Improved high performance liquid chromatographic method for determination of carotenoids in the microalga Chlorella pyrenoidosa

Microalgae have become an important commercial source of carotenoids and microalgae-derived functional foods are consumed by people worldwide. Therefore, an HPLC method was developed to discern the variety and content of carotenoids in the microalga Chlorella pyrenoidosa. The microalga sample was powdered, extracted, saponified and subjected to HPLC analysis. A mobile phase of methanol-acetonitrile-water (84:14:2, v/v/v) (A) and methylene chloride (100%) (B) with the following gradient elution was developed: 100% A and 0% B in the beginning, maintained for 14 min, decreased to 95% A in 25 min, 75% A in 30 min, 74% A in 35 min, 45% A in 50 min and returned to 100% A in 55 min. A total of 32 carotenoids were resolved within 49 min by using a C30 column with flow rate at 1 mL/min and detection at 450 nm. An internal standard beta-apo-8'-carotenal was used to quantify all the carotenoids. All-trans-lutein was present in exceptionally large amount (125034.4 microg/g), followed by cis isomers of lutein (27975.3 microg/g), all-trans-alpha-carotene (2465.8 microg/g), zeaxanthin (2170.3 microg/g), cis isomers of beta-carotene (2159.3 microg/g), all-trans-beta-carotene (2155.0 microg/g), cis isomers of alpha-carotene (1766.7 microg/g), beta-cryptoxanthin (334.9 microg/g), neoxanthin and its cis isomers (199.7 microg/g), neochrome (65.2 microg/g), auroxanthin (38.5 microg/g) and violaxanthin and its cis isomers (38.1 microg/g).     

Improved liquid chromatographic method for the analysis of photosynthetic pigments of higher plants

The paper presents an improved reversed-phase LC method for the separation of the pigments from green leaves. A good separation of carotenoids and of their cis- and trans-isomers was achieved, especially for the separation of trans-lutein, zeaxanthin, cis-lutein, which are usually not well separated. No perfect separation of alpha-carotene, beta-carotene and pheophytin a was possible, but conditions for a perfect coelution of pheophytin a with either beta-carotene or alpha-carotene were established. Simultaneous equations allowing the determination of pheophytin a and alpha-carotene or pheophytin a and beta-carotene are also given.     

Extraction and chromatography of carotenoids from pumpkin

Vitamin A deficiency is a health problem in Southeast Asia that can be corrected by feeding orange fruits and vegetables such as mango. Pumpkin is a traditional Korean food that is easy to store and is already believed to have health benefits. We extracted carotenoids from pumpkin by liquid-liquid extraction and by supercritical fluid extraction. We measured carotenoids by reversed-phase chromatography with diode array detection. The major carotenoid in pumpkin (> 80%) is beta-carotene, with lesser amounts of lutein, lycopene, alpha-carotene and cis-beta-carotene. Pumpkin is a rich source of beta-carotene and might be useful for preventing Vitamin A deficiency.     

Measurements of the major isoforms of vitamins A and E and carotenoids in the blood of people with spinal-cord injuries

We used reversed-phase HPLC with diode array detection to simultaneously measure the major isoforms of vitamins A, E, and the carotenoids in serum from 55 healthy people with spinal cord injuries. Typically, the method measured retinol (vitamin A), alpha-tocopherol (vitamin E) and beta-carotene, alpha-carotene, lutein, lycopene, and cryptoxanthin (carotenoids). gamma-Tocopherol (vitamin E), 25-hydroxycalciferol (vitamin D), and the carotenoid zeaxanthin could also be measured when they were present in high concentrations. Healthy people with spinal cord injuries were more likely than similar people without injuries to have low concentrations of alpha-tocopherol, and to a lesser extent retinol and beta-carotene.     

Divergent optimum levels of lycopene,beta-carotene and lutein protecting against UVB irradiation in human fibroblastst

Exposure of living organisms to UV light leads to photooxidative reactions. Peroxyl radicals are involved in the propagation of lipid peroxidation. Carotenoids are dietary antioxidants and show photoprotective effects in human skin, efficiently scavenging peroxyl radicals and inhibiting lipid peroxidation. Cultured human skin fibroblasts were used to examine the protective effects of the carotenoids, lycopene, beta-carotene and lutein on UVB-induced lipid peroxidation. The carotenoids were delivered to the cells using liposomes as the vehicle. The cells were exposed to UVB light for 20 min. Lycopene, beta-carotene and lutein were capable of decreasing UV-induced formation of thiobarbituric acid-reactive substances at 1 h to levels 40-50% of controls free of carotenoids. The amounts of carotenoid needed for optimal protection were divergent at 0.05, 0.40 and 0.30 nmol/mg protein for lycopene, beta-carotene and lutein, respectively. Beyond the optimum levels, further increases of carotenoid levels in cells led to prooxidant effects.     

Separation and characterization of antioxidants from Spirulina platensis microalga combining pressurized liquid extraction, TLC, and HPLC-DAD

A new procedure has been developed to separate and characterize antioxidant compounds from Spirulina platensis microalga based on the combination of pressurized liquid extraction (PLE) and different chromatographic procedures, such as TLC, at preparative scale, and HPLC with a diode array detector (DAD). Different solvents were tested for PLE extraction of antioxidants from S. platensis microalga. An optimized PLE process using ethanol (generally recognized as safe, GRAS) as extraction solvent has been obtained that provides natural extracts with high yields and good antioxidant properties. TLC analysis of this ethanolic extract obtained at 115 degrees C for 15 min was carried out and the silica layer was stained with a DPPH (diphenyl-pycril-hydrazyl) radical solution to determine the antioxidant activity of different chromatographic bands. Next, these colored bands were collected for their subsequent analysis by HPLC-DAD, revealing that the compounds with the most important antioxidant activity present in Spirulina extracts were carotenoids, as well as phenolic compounds and degradation products of chlorophylls.     

High performance liquid chromatographic analysis of phytoplankton pigments using a C16-amide column

In this study, a reverse-phase HPLC method incorporating a ternary solvent system was developed to analyze most polar and non-polar chlorophylls and carotenoids present in phytoplankton. The method is based on an RP-C₁₆-Amide column and provided excellent peak resolution of most taxonomically important pigments and an elution profile different than C₈ or C₁₈ columns provide. Analysis of mixed pigment standards, extracts of phytoplankton monocultures, and field samples showed that this method was able to resolve more than sixty pigments, ranging from very polar acidic chlorophylls to the non-polar hydrocarbon carotenes in less than 36 min. This included chlorophylls c₁, c₂ and c₃, divinyl chlorophylls a and b, the carotenoids lutein and zeaxanthin and some recently discovered pigments. The ability of this method to resolve divinyl chl b from monovinyl chl b and divinyl chl a from monovinyl chl a is particularly important for the quantification and identification of the marine cyanobacteria Prochlorococcus spp. in oceanic waters. The described protocol is sensitive and reproducible and can be used to assess the distribution and dynamics of major phytoplankton groups in marine and freshwater ecosystems.