应用ICP-AES快速测定石油产品中多种元素

研究了ICP-AES测定润滑油中的多种元素,以及测定元素的检出限、重现性和回收率并与GB/T17476-1998的有关规定进行了比较,结果表明ICP-AES法进行多元素同步测定,具有结果可靠、操作方便,测定快捷,检出限低,重现性好和回收率高的优点。     

大气颗粒物重金属元素分析技术研究进展

大气颗粒物已经成为当前大气环境首要污染物,而其中重金属由于具有非降解性和滞后性,严重威胁人类生命和自然环境,已成为当前研究热点。对分析大气颗粒物中重金属元素所用原子吸收光谱法、电感耦合等离子体原子发射光谱法、电感耦合等离子体质谱法、荧光光谱法、中子活化法、辉光放电原子发射光谱法、微波等离子体原子发射光谱法和激光诱导击穿光谱法进行了综述,并尝试对这些技术的不足之处提出一些改进建议：连续光源原子吸收光谱法同时测定多种元素,原子发射光谱法直接测定颗粒物,高分辨率激光剥蚀电感耦合等离子质谱法测定固体样品,低散射同步加速荧光法测定大气颗粒物和k₀中子活化法测定对流层发射性元素。大气颗粒物重金属元素的时空分布差异和人类对环境空气质量要求的提高以及现代仪器科学技术的高速发展促使大气颗粒物重金属元素分析技术朝着实时、快速、检出限低、直接测定和操作简便的方向发展。     

微波消解-火焰原子吸收光谱法测定蕨麻中8种矿物元素

利用微波消解,空气-乙炔火焰原子吸收光谱法对蕨麻中钾、钠、钙、镁、铜、锌、铁、锰8种人体必需矿物元素进行了测定。对样品的预处理方法、仪器的测定条件、共存元素的干扰及消除进行了研究,并对各测定元素进行了加标回收率实验。结果表明,在选定的实验条件下,该法的相对标准偏差均小于2.5%(n=8),各元素加标回收率为96.5%—103.2%。     

ICP-AES法测定镍基高温合金中16个元素的方法研究

该方法采用ICP-AES法对镍基高温合金中16个元素进行了测定,系统研究了基体元素和共存元素对分析元素谱线的光谱干扰情况,进行了分析线的选择,测定了方法检出限,通过准确度试验和精密度试验,表明该方法准确、可靠、简便、快速。     

不同前处理方法对ICP-AES测定枸杞元素含量的影响

用ICP-AES测定中药材枸杞中锌、铅、锰、铁、铬、镁、钙、铜、钠、钾、镉11种元素。比较了常规湿法消化法、高压消化罐法和微波消解法处理样品对测定结果的影响。研究结果表明,高压消化罐法和微波消解处理样品,精密度和回收率较好。在选定的实验条件下,各元素间互不干扰,可在同一样品液中进行多种元素的分别测定。利用该方法测定其回收率在92.9%—101.0%之间,相对标准偏差在0.72%—2.40%之间。     

ICP-AES法测定铝合金中钪元素的方法研究

本方法采用ICP-AES法进行铝合金中Sc元素的测定,系统研究了四十余种元素对Sc三条分析谱线的光谱干扰情况,进行了分析线的选择,分别用酸溶解法和碱溶解法溶解铝合金样品,测定了方法检出限,方法回收率98％-100.3％。该方法准确、可靠、简便、快速。     

弧形小平台-塞曼电热原子吸收光谱法测定铂和铑的研究

一、前言电热原子吸收光谱法测定贵金属元素的灵敏度虽高,但如有大量基体元素存在时,对直接测定贵金属有显著影响。据Kritsotakis等报道,200倍的Cu、Ph、Cr、Ag等就干扰Pt的测定。1977年,L'vov提出了在石墨管中采用平台技术,使得被测元素原子化在更接近于恒温的条件下进行,从而减小了被测元素所遭受的气相干扰。我们根据日立原子吸收仪的特点,自行设计并用全热解石墨材料制造了一种弧形小平台,研究了用小平台及常规管壁法(简称管壁法)测定Pt和Rh时,二十多种共存元素对测定所产生的影响。试验结果表明,采用该平台技术以后,共存元素的干扰受到很大的抑制,共存元素的最大允许最较管壁法有很大的提高。     

ICP-AES测定钢中的微量钒、铈、钛

采用ICP－AES法同时测定了钢中微量V、Ce、Ti,并研究了基体元素和共存元素对分析元素的光谱干扰，无需用基体匹配。进行了加入回收试验、精密度试验和方法检出限的测定。方法准确、可靠、简便、快速。     

ICP-AES法测定钛基复合材料中的Al、Mo、B的研究

本文采用ＩＣＰ－ＡＥＳ法对钛基复合材料中的合金元素Ａｌ、Ｍｏ、Ｂ的测定进行研究,着重进行了基体元素对待测元素Ａｌ、Ｍｏ、Ｂ的干扰试验及各元素在测定浓度范围内线性相关性,进行了酸度试验,测定了钛基复合材料中上述三元素的含量,得到了较好的精密度和准确度。     

氢化物发生-电感耦合等离子体原子发射光谱法同时测定人发中氢化元素和非氢化元素

采用连续氢化物发生法,在酸性介质中,对人发样品中可形成氢化物的元素（As,Se,Pb,Hg,Sb)和棵氢化元素（Zn,Cr,Mg,Mn,Ca,Fe,Cu,Ni,Cd,Al,Co,Mo,Ba)进行同时测定。研究了酸度、NaBH4的浓度、载气流速、清洗时间对氢化元素的影响,比较了传统雾法和（雾化＋氢化法）对氢化元素和非氢化元素的影响,选择了最佳分析条件。对标准人发样品中的18种元素进行了测定,结果令人满意。     

Folin-Ciocalteu比色法测定石榴皮提取物中的多酚

研究Folin-Ciocalteu比色法测定石榴皮提取物中多酚含量的优化条件,并对该方法的稳定性、精密度、重现性、回收率进行了实验。结果表明,石榴皮提取物中多酚含量测定的最佳条件为:Folin-Ciocalteu试剂1.00mL、10.0g/100mL Na2CO33.00mL、反应温度25℃、反应时间120min、测定波长672nm,所用没食子酸标准品在10—100μg/mL范围内与吸光度呈良好的线性关系(y=0.0098x+0.0148,R2=0.9982)。该法简便、快速、准确,是检测石榴皮提取物中总多酚的可靠方法。     

Surface‐enhanced Raman spectroscopy (SERS) on silver colloids for the identification of ancient textile dyes. Part II: pomegranate and sumac

The effectiveness of surface‐enhanced Raman spectroscopy (SERS) spectrocsopy on Ag colloids has been successfully demonstrated for the identification of a yellow dye in two ancient wool threads found in the Royal Tumulus of In Aghelachem, Libyan Sahara, belonging to the Garamantian period (2nd–3rd century A.D.). High‐performance liquid chromatography (HPLC) highlighted the presence of ellagic acid in the extracts from the threads, excluding other chromophores. This result, together with the abundance of malic acid detected by gas chromatography‐mass spectrometry (GC‐MS), suggested the possible use of pomegranate rind or sumac berries as source of the yellow dye, both plants being documented in the Fezzan area during the Garamantian period. HPLC analyses and SERS spectra acquired on the extracts of the ancient threads were therefore compared with those obtained from pomegranate and sumac extracts of the corresponding fruits and reference dyed wool samples, allowing us to identify the yellow dye as deriving from pomegranate (Punica granatum L.). SERS spectra of ellagic acid and dyes extracted from pomegranate rind and sumac berries are reported here for the first time. A methodological improvement is also presented, based on the use of NaClO₄ as aggregating agent, that leads to a significant increase of the signal‐to‐noise ratio in the SERS spectra. Copyright © 2010 John Wiley & Sons, Ltd.     

Simultaneous process optimization of ultrasound-assisted extraction of polyphenols and ellagic acid from pomegranate (Punica granatum L.) flowers and its biological activities

This study was designed to optimize the extraction rate of total polyphenols and ellagic acid from pomegranate flowers. Single factors were investigated for liquid-to-material ratio (5–25), ethanol concentration (20%–60%), sonication time (5–60 min), and sonication power (150–500 W). The level range of the Box-Bokhen design was determined with respect to the single-factor results. The components of each index were normalized using the entropy weighting method for obtaining the comprehensive evaluation value. Under the actual conditions, the final optimization results were 17 for liquid-to-material ratio, 43% for ethanol concentration, 10 min for ultrasonic time, and 300 W for ultrasonic power. The extracts obtained under optimal conditions were tested for the inhibition of Streptococcus mutans and its biofilm, and results showed that pomegranate flowers exerted some inhibitory effects on the bacterium. Phosphomolybdenum and FRAP assays were used, and DPPH, ABTS, and O²⁻ radical scavenging tests were conducted, indicating that pomegranate flower extracts have good antioxidant capacity.     

Green ultrasound-assisted extraction of carotenoids from pomegranate wastes using vegetable oils

The objective of this work was to develop a new process for pomegranate peels application in food industries based on ultrasound-assisted extraction of carotenoids using different vegetable oils as solvents. In this way, an oil enriched with antioxidants is produced. Sunflower oil and soy oil were used as alternative solvents and the effects of various parameters on extraction yield were studied. Extraction temperature, solid/oil ratio, amplitude level, and extraction time were the factors investigated with respect to extraction yield. Comparative studies between ultrasound-assisted and conventional solvent extraction were carried out in terms of processing procedure and total carotenoids content. The efficient extraction period for achieving maximum yield of pomegranate peel carotenoids was about 30 min. The optimum operating conditions were found to be: extraction temperature, 51.5 °C; peels/solvent ratio, 0.10; amplitude level, 58.8%; solvent, sunflower oil. A second-order kinetic model was successfully developed for describing the mechanism of ultrasound extraction under different processing parameters.     

Continuous and pulsed ultrasound-assisted extractions of antioxidants from pomegranate peel

There is a great demand for developing efficient extraction methods in order to reduce extraction time and increase the yield and activity of functional antioxidants. The yields, activities, and extraction kinetics of antioxidants from dry peel of pomegranate marc were studied using ultrasound-assisted extraction in continuous and pulsed modes and the results were compared with conventional extraction (CE) at a temperature of 25±2°C and water/peel ratio of 50/1, w/w. The studied factors were intensity level and treatment time for continuous ultrasound-assisted extraction (CUAE), and intensity level, number of pulse repetition, and pulse duration and interval for pulsed ultrasound-assisted extraction (PUAE). The results showed that all factors significantly affected the antioxidant yield, but only treatment time had a significant effect on the antioxidant activity. Compared to CE, PUAE at intensity level of 59.2 W/cm(2), and the 5 and 5s of pulse duration and interval increased the antioxidant yield by 22% and reduced the extraction time by 87%. Similarly, CUAE at the same intensity level increased the antioxidant yield by 24% and reduced the extraction time by 90%. Since PUAE had 50% energy saving compared to CUAE, we recommend using PUAE for the extraction with antioxidant yield of 14.5% and DPPH scavenging activity of 5.8 g/g. A second-order kinetic model was successfully developed for describing the mechanism of ultrasound-assisted extractions under PUAE and CUAE. This research clearly demonstrated the superiority of PUAE for producing antioxidants from peel of pomegranate marc.     

Ultrasonic potential in maintaining the quality and reducing the microbial load of minimally processed pomegranate

Difficulty of Pomegranate fruit peeling and arils separation are the main motivations of progressive ready-to-eat pomegranate fresh arils industry. Also, extracted pomegranate arils are highly perishable due to water loss and microbial contamination expose. The aim of the current work was then to evaluate the effect of ultrasound for 15 and 30 min on maintenance of bioactive compounds and microbial load reduction of pomegranate arils cv. Rabbab. Treated arils were kept at 5 °C and analyzed during 15 days of storage. The most and least weight loss of arils obtained in control and 30 min treated samples, respectively. After 12 days of storage, all samples were decayed except those treated for 15 and 30 min. The ultrasound treatment significantly prevented degradation of anthocyanin and ascorbic acid compounds. Total phenol and antioxidant activity decreased during storage. At the end of storage, the most total phenol content (3898.6 mg GAE L⁻¹) was found in arils treated for 30 min whereas the most anthocyanin (91.93 mg L⁻¹), total antioxidant activity (82.65%), and ascorbic acid (2.53 mg L⁻¹) were found in arils treated for 15 min. Ultrasound treated arils had lower microbial load (total mesophilic bacteria in control and 30-min treated samples) in each stage during storage. At the end of storage, the microbial load in treated and control arils was 0.7 and 0.2 Log CFU g⁻¹, respectively). Overall, ultrasound treatment effectively reduced weight loss and preserved bioactive compounds during storage.     

Effect of high hydrostatic pressure processing and squeezing pressure on some quality properties of pomegranate juice against thermal treatment

The aim of this study was to investigate the effect of high hydrostatic pressure (HHP) treatment (200, 300, 400?MPa; 5°C, 15°C and 25°C; 5 and 10 min) on some quality properties of pomegranate juice. Juice samples are obtained under industrial conditions at two different squeezing pressure levels (100 and 150?psi – 0.689 and 1.033?MPa, respectively). Results are compared against conventional thermal treatment (85°C/10 min) and raw sample. For all three processing temperature, HHP combinations at 400?MPa for 10 min were sufficient to decrease the microbial load around 4.0 log cycles for both squeeze levels. All HHP treatments showed no significant decrease at antioxidant activity, total phenolic content and monomeric anthocyanin pigment concentrations, while there was a significant decrease (p?≤?.05) in thermal-treated samples. Being the highest sugar alcohol in pomegranate juice, mannitol content must be considered for determining the authenticity, and mannitol content increased with squeezing pressure and thermal treatment.     

Continuous and pulsed ultrasound-assisted extractions of antioxidants from pomegranate peel

There is a great demand for developing efficient extraction methods in order to reduce extraction time and increase the yield and activity of functional antioxidants. The yields, activities, and extraction kinetics of antioxidants from the dry peel of pomegranate marc were studied using ultrasound-assisted extraction in continuous and pulsed modes and the results were compared with conventional extraction (CE) at a temperature of 25 ± 2 °C and water/peel ratio of 50/1, w/w. The studied factors were intensity level and treatment time for continuous ultrasound-assisted extraction (CUAE), and intensity level, number of pulse repetition, and pulse duration and interval for pulsed ultrasound-assisted extraction (PUAE). The results showed that all factors significantly affected the antioxidant yield, but only treatment time had a significant effect on the antioxidant activity. Compared to CE, PUAE at an intensity level of 59.2 W/cm², and a pulse duration of 5 s and a resting interval of 5 s increased the antioxidant yield by 22% and reduced the extraction time by 87%. Similarly, CUAE at the same intensity level increased the antioxidant yield by 24% and reduced the extraction time by 90%. Since PUAE had 50% energy saving compared to CUAE, we recommend using PUAE for the extraction with antioxidant yield of 14.5% and DPPH scavenging activity of 5.8 g/g. A second-order kinetic model was successfully developed for describing the mechanism of ultrasound-assisted extractions under PUAE and CUAE. This research clearly demonstrated the superiority of PUAE for producing antioxidants from peel of pomegranate marc.     

光谱法分析研究新疆瓜果微量元素含量

利用原子吸收法和原子发射法对新疆十一类瓜果八种微量元素进行检测,并与中国生物标准进行比较分析。 结果发现,新疆和田地区苹果含锌66.75 mg·kg-1、含钾819.2 mg·kg-1、含锰4.657 mg·kg-1,大枣含锶8.62 mg·kg-1;新疆库尔勒地区石榴含钾687 mg·kg-1;新疆哈密地区大枣锰、锌、锶、钙、铁、镍和钾七种微量元素含量均高出各相应的中国生物标准;在十一类瓜果中铜元素含量均低于中国生物标准;八种微量元素含量平均值在新疆库尔勒石榴、新疆和田苹果、新疆哈密大枣中表现很高（分别为91.82, 121.5, 275.3 mg·kg-1）;在新疆五家渠种植的西瓜中八种微量元素表现出果皮中平均含量（54.19 mg·kg-1)是瓤中平均含量(48.69 mg·kg-1)的1.11倍。其研究结果对新疆瓜果营养成分研究提供科学的基础数据。     

Effects of natural antioxidants and high-energy fabrication methods on physical properties and oxidative stability of flaxseed oil-in-water nanoemulsions

The effects of high-energy fabrication methods, namely high-pressure homogenization (HPH) and ultrasonication (US), on physicochemical properties of flaxseed oil-in-water nanoemulsions (FNEs) containing clove essential oil (CEO) and/or pomegranate peel extract (PPE) were studied during storage at 4 and 25 °C. Nanoemulsions with relatively similar average droplet size were prepared by HPH and/or US. An increase in droplet size was observed over time. Lower storage temperature and fabrication by US increased Ostwald ripening rate. Higher storage temperature and fabrication by US decreased the centrifugal stability of nanoemulsions. CEO revealed better antioxidant properties than PPE. The oxidative stability was evaluated by determining secondary oxidation products, and fatty acids profile. The absence of antioxidant, fabrication by US, and higher storage temperature decreased the oxidative stability of nanoemulsions. The results of this study might be helpful in controlling the oxidation of FNEs during long-term storage and in designing functional foods and beverages.