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Anthocyanins constitute a major group of natural pigments, and they are responsible for the colours of fruits and vegetables. A rapid and feasible assay procedure for the determination of free forms of the six most abundant anthocyanins in foods is described. The 3-glucoside forms of pelargonidin, cyanidin, peonidin, delphinidin, petunidin and malvidin with the aglycone cyanidin (as internal standard) were separated by gradient elution and quantified using HPLC-DAD within 18 min. A fast sample preparation step was employed which allows direct injection of samples to the chromatograph without need of chemical extraction. Testing on 28 different vegetable, fruit and processed commercial product samples demonstrated applicability in the concentration range of about 80–420 ng/mL with an accuracy of 99.2 ± 0.2% and an average precision of 0.8%. The method was suggested as a cheap and robust alternative to the previous ones that employ multi-step sample treatment protocols. 相似文献
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Carine Viana Gabriela M. Zemolin Larissa S. Müller Thaís R. Dal Molin Helena Seiffert Leandro M. de Carvalho 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2016,33(1):1-9
Methyl-xanthines and adrenergic stimulants, such as caffeine and synephrine, are commonly added to food supplements due to their stimulating and thermogenic effects. In addition, the abusive consumption of food supplements with ergogenic and aesthetic purposes has been observed worldwide. This work describes the study of caffeine, p-synephrine, hordenine, octopamine, tyramine, ephedrine and salicin as stimulants in dietary supplements marketed in Brazil for weight loss and physical fitness claims. A total of 94 different products were acquired from 30 Brazilian websites. Thus, the sampling of marketed supplements was performed in virtual commerce (e-commerce) with claims of weight loss, appetite reduction, fat burning and metabolism acceleration. The developed analytical method involved the separation of the stimulants by HPLC with diode array detection (HPLC-DAD) by using a gradient elution of flow rate (0.7–2.5 ml min?1) and mobile phase composition (0.1% H3PO4/methanol). The validated method was applied to the study of 46 dietary supplements. Caffeine, p-synephrine and ephedrine were found to be present as stimulants in 52% of the studied samples marketed as encapsulated or bulk forms. Caffeine was found to be present in concentrations that represent doses from 25.0 to 1476.7 mg day–1. Synephrine was found in concentrations that represent doses from 59.1 to 127.0 mg day–1. Ephedrine was found to be associated with caffeine in one formulation at a concentration representing a 26.1 mg day–1 dosage. 相似文献
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《分离科学与技术》2012,47(18):3082-3090
ABSTRACTThis study aimed at extracting and separating anthocyanins from Nitraria tangutorun Bobr. fruit using deep eutectic solvent (DES) combined with macroporous resins. Choline chloride/1,2-propanediol (ChCl-Prop)-based DESs produced higher extraction yields of total anthocyanins from N. tangutorun fruit than pure water and ethanol/methanol/acetone aqueous solutions did, and LX-32 macroporous resin was used to separate total anthocyanins from the DES (recovery>95%). Additionally, a green and efficient HPLC-DAD method was used for the analysis of total anthocyanins using ethanol and a tartaric acid aqueous solution as mobile phases, and 13 anthocyanins were identified from N. tangutorun fruit using a UPLC-Q-TOF-MS method.Abbreviations: DES, deep eutectic solvent; ChCl-Prop, choline chloride/1,2-propanediol. 相似文献
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2007版《化妆品卫生规范》规定,使用HPLC-DAD法检测化妆品中的苯酚,如有阳性结果,必须用GC-MS法进行验证。采用GC-MS法对含有水杨酸的化妆品进行检测,考察水杨酸对苯酚测定的影响。结果表明,水杨酸对热不稳定,在GC-MS检测条件下会高温分解并释放出苯酚,且热降解程度随着进样口温度的升高而显著增强。用GC-MS法检测含有水杨酸的化妆品时,会得到苯酚含量偏高或假阳性的检测结果。 相似文献
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Optimization of extraction and determination of emodin from Polygonum cuspidatum Sieb. et Zucc. products by HPLC-DAD 总被引:1,自引:0,他引:1
A uniform experimental design procedure was used to investigate the effects of some operating parameters on the extraction of emodin from Polygonum cuspidatum Sieb. et Zucc. products. Variables tested were volume ratio of material to solvent, size of material, extraction time and temperature and composition of extraction solvent (mixtures of acetone-water). Each variable was tested at seven levels; 7 experiments were performed in random order. Analyses of the extracts were performed by high-performance liquid chromatography with diode array detection(HPLC-DAD). Analytical responses were processed by using a forward regression analysis, in order to find polynomial function describing the relationship between variables and responses. For all the analytes the experimental conditions for providing the highest extraction yield inside the experimental domain considered were found. Finally, a simple, rapid and accurate analytical method was developed for the determination of emodin by high performance liquid chromatography. The separation is achieved within 25 rain on an ODS column using methanol and water as gradient mobiles. Emodin can be quantified by using external standard method detecting at 436 nm. Good linearity is obtained with correlation coefficient exceeding 0.9986 and the detection limit and the quantification limit are 1.53 and 3.23 mg/L respectively. This method shows good reproducibility for the quantification of the emodin with intra-day and inter-day relative standard deviation less than 2.3% and 5.6% respectively. Under optimized extraction conditions, the recovery of the standard is 96.5%. The validated method is successfully applied to quantify the emodin in seven Polygonum cuspidatum sieb. Et zucc. products, which provided an idea for the pre-treatment of determination of active compounds in traditional Chinese medicines. 相似文献
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Jiri Pikula Hana Bandouchova Klara Hilscherova Veronika Paskova Jana Sedlackova Ondrej Adamovsky Zora Knotkova Jiri Machat Ladislav Novotny Frantisek Vitula 《The Science of the total environment》2010,408(21):4984-4992
Under environmental conditions, wild birds can be exposed to multiple stressors including natural toxins, anthropogenic pollutants and infectious agents at the same time.This experimental study was successful in testing the hypothesis that adverse effects of cyanotoxins, heavy metals and a non-pathogenic immunological challenge combine to enhance avian toxicity. Mortality occurred in combined exposures to naturally occurring cyanobacterial biomass and lead shots, lead shots and Newcastle vaccination as well as in single lead shot exposure. Mostly acute effects around day 10 were observed. On day 30 of exposure, there were no differences in the liver accumulation of lead in single and combined exposure groups. Interestingly, liver microcystin levels were elevated in birds co-exposed to cyanobacterial biomass together with lead or lead and the Newcastle virus. Significant differences in body weights between all Pb-exposed and Pb-non-exposed birds were found on days 10 and 20. Single exposure to cyanobacterial biomass resulted in hepatic vacuolar dystrophy, whereas co-exposure with lead led to more severe granular dystrophy. Haematological changes were associated with lead exposure, in particular. Biochemical analysis revealed a decrease in glucose and an increase in lactate dehydrogenase in single and combined cyanobacterial and lead exposures, which also showed a decreased antibody response to vaccination.The combined exposure of experimental birds to sub-lethal doses of individual stressors is ecologically realistic. It brings together new pieces of knowledge on avian health. In light of this study, investigators of wild bird die-offs should be circumspect when evaluating findings of low concentrations of contaminants that would not result in mortality on a separate basis. As such it has implications for wildlife biologists, veterinarians and conservationists of avian biodiversity. 相似文献
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HPLC-DAD法测定馒头中喹啉黄、食用绿S和亮绿3种色素含量的研究 总被引:1,自引:0,他引:1
建立了高效液相色谱(HPLC)串联紫外器(DAD)测定馒头中3种色素含量的方法。以无水乙醇—氨水—水(7:2:1)溶液作为提取溶剂,用超声辅助提取样品中的色素,用HPLC-DAD进行检测,检测波长425 nm、624 nm,色谱柱为PAK CAPCELL C_(18)(5μm,4.6×200 mm),流速1.0 mL·min~(-1),柱温35℃,以甲醇-乙酸铵溶液为流动相进行梯度洗脱。结果表明:3种色素分离度较好,具有良好的线性关系(r=0.999 9),重现性、精密度良好(RSD%均小于3%),检出限食用绿S为0.848 4 ng、喹啉黄为6.833 9 ng、亮绿为1.336 0 ng,平均加标回收率为91%~105%。该方法简单、快速、灵敏度高、回收率高、检出限低,适用于馒头中喹啉黄、食用绿S、亮绿含量的测定。 相似文献
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Anna Angela Barba 《LWT》2008,41(10):1919-1926
Phenolic compounds have long been associated with flavour and colour characteristics of fruits and vegetables and actually attract a great interest due to their health protecting properties. In this work, the influence of different power input of microwave baking on the amount of protocatechuic acid (1), tryptophan (2), chlorogenic acid (3), neo-chlorogenic acid (4), and cryptochlorogenic acid (5) marker compounds left over in peeled and not-peeled potatoes (Solanum tuberosus L., Agria cultivar) was assessed. A high-performance liquid chromatographic (HPLC) method with diode-array detection (DAD) was used to identify and quantify compounds 1-5. Other tubers were used to perform analysis of raw potato (control) and traditional baking potatoes products (boiled potatoes). Dielectric behavior of the irradiated tubers was also investigated to emphasize if microwaves treatments are suitable for food processing in terms of nutritional factor preservation. The main results of this work consist on the relevance of the water contents in potato matrixes during the baking processes since these have a crucial role to keep lossy features, to avoid thermal damages and to preserve antioxidant. The best compromise in terms of short baking time and reduced water and phenolic losses is obtained using 500 W as power input. 相似文献