Dispersive Liquid–Liquid Microextraction Followed by Magnetic Solid-Phase Extraction for Determination of Four Parabens in Beverage Samples by Ultra-performance Liquid Chromatography Tandem Mass Spectrometry

In this study, a two-step extraction technique was developed for extraction and preconcentration of parabens from beverage samples using ionic liquid dispersive liquid–liquid microextraction (IL-DLLME) and magnetic solid-phase extraction (MSPE). In this IL-DLLME followed by MSPE method, ionic liquid (IL, 1-octyl-3-methylimidazolium hexafluorophosphate) formed hydrophobic microdroplets in beverage samples as an extractant of parabens; after the IL-DLLME process was completed, graphene modified Fe₃O₄ nanoparticles (Fe₃O₄@G) were placed to adsorb and isolate IL from the sample solution. After the supernatant was carefully moved, acetonitrile was added to elute the IL containing parabens from Fe₃O₄@G. The experimental variables affecting the extraction procedure have been systematically studied. Under optimal conditions, the detection limits were less than 1.53 ng/mL and the linear detection ranges were 2–500 ng/mL (R ² ≥ 0.998) for these analytes. The recoveries for spiked samples were 58.8–89.2% and satisfactory precision (RSD ≤ 4.8%) were obtained.     

Modified QuEChERS Combination with Magnetic Solid-Phase Extraction for the Determination of 16 Preservatives by Gas Chromatography–Mass Spectrometry

In this paper, based on the mechanism of the quick, easy, cheap, effective, rugged and safe (QuEChERS) method, a novel graphene grafted silica-coated Fe₃O₄ (Fe₃O₄@SiO₂@G) was synthesized and applied as the efficient magnetic solid-phase extraction (MSPE) adsorbent for rapid cleanup of vegetable samples prior to analyzing 16 preservative residues by gas chromatography–mass spectrometry (GC-MS). The method, which took advantages of the novel nanoparticle adsorbent and an external magnetic field separation targets from samples, not only could avoid the time consuming of the traditional solid-phase extraction, but also could be developed for simultaneous determination of 16 preservative residues in vegetables. Various experimental parameters that could affect the extraction efficiencies have been investigated. Under the optimum conditions, 16 preservatives showed good linearity over the range of 0.02–2.00 mg/L and correlation coefficients (R ²) of 0.9946–0.9998. The limits of detections (LODs) were in the range of 0.21–11.50 μg/kg. The recoveries of 16 preservatives ranged from 78.3 to 116.7 %, and the relative standard deviations (RSDs) ranged from 1.4 to 11.9 %.     

Rapid Determination of Trace Sulfonamides in Milk by Graphene Oxide-Based Magnetic Solid Phase Extraction Coupled with HPLC–MS/MS

A simple and rapid method based on magnetic solid-phase extraction (MSPE) combined with high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (HPLC–MS/MS) was used for the determination of 15 sulfonamides from milk samples. The extraction and cleanup used a graphene oxide-based magnetic nanocomposite (Fe₃O₄@GO) as an adsorbent. Various experimental parameters that could affect the extraction efficiencies, such as the amount of Fe₃O₄@GO, the extraction time, the ionic strength of sample solution, and the type of eluent, were investigated. Under optimized experimental conditions, good linearity was observed in the range of 2.0 to 100.0 μg L^?1 for all of the analytes, with correlation coefficients (R²) ranging from 0.994 to 0.999. The limits of detection for the method ranged between 0.02 and 0.13 μg L^?1. Mean values of the relative standard deviation of intraday and interday precision ranging from 1.0 to 7.3 % and from 1.7 to 8.1 % were obtained, respectively. The average recoveries were between 73.4 and 97.4 % at three different spiked levels. It was confirmed that the Fe₃O₄@GO nanocomposite was an effective MSPE material for use in sulfonamide analyses in milk samples.     

Magnetic cotton yarns – optimization of magnetic properties

In this paper, we present the effect of ferrite percentage content and electric current intensity passing through the electromagnet coil on magnetic properties (saturation induction, residual induction, and coercive field) of magnetic staple yarns. Also, we present a method for obtaining magnetic yarns by direct coating with magnetic powder (barium ferrite). The aim of the study is to determine the optimal processing factors that can affect the performance of magnetic characteristics using an experimental design for second-order model. The results show that an increase in ferrite percentage content is influencing the saturation and residual induction more than an increase in applied current intensity. The increase in saturation and residual induction is due to the higher content of ferrite powder from the magnetic solution that adheres on the yarn surface. The higher is the value of coercive field, the larger is the force needed to completely demagnetize the magnetic yarn.     

Biosensing Applications of Modified Core–Shell Magnetic Nanoparticles

Fe₃O₄ magnetic nanoparticles (MNPs) were synthesized and silanized to form a core–shell (Fe₃O₄–SiO₂) structure. Afterwards, surface modification with amino silane was carried out to produce amino groups on the MNPs for the biomolecule immobilization. In order to test the performance of amino functional MNPs as immobilization platform in biosensing applications, glucose oxidase was immobilized on the surface via glutaraldehyde. Obtained Bio-MNPs were then fixed onto the carbon paste electrode by the aid of magnetic force and used as the working electrode during the amperometric measurements at −0.7 V versus Ag/AgCl. After optimization of some parameters affecting the biosensor performance, analytical characterization was carried out. Linearity was found in the range of 0.25–2.0 mM glucose and defined by the equation of y = 8.366x + 1.819, (R ² = 0.996). Proposed biosensor was then applied for the glucose analysis in various beverages. Finally, data were compared with a commercial enzyme assay kit based on spectrophotometric Trinder reaction as a reference method.     

Ionic Liquid-Based Surfactant Extraction Coupled with Magnetic Dispersive μ-Solid Phase Extraction for the Determination of Phthalate Esters in Packaging Milk Samples by HPLC

A highly selective sample cleanup procedure combining ionic liquid-based surfactant extraction (ILSE) and magnetic dispersive μ-solid phase extraction (MD-μ-SPE) was triumphantly developed for the synchronously extraction of four phthalate acid esters (PAEs) in packaging milk samples prior to high-performance liquid chromatography coupled with photodiode array detector (HPLC-DAD). In this ionic liquid (IL)-based surfactant method, 1-octyl-3-methylimidazolium hexafluorophosphate ([C₈MIM] [PF₆]) was used as extraction solvent, anionic surfactant sodium linear alkylbenzene sulfonate (LAS) was used as auxiliary extraction solvent, and then sodium chloride (NaCl) was mixed to drive phase separation. The synthesized hydrophobic diatomaceous earth-supported Fe₃O₄ magnetic nanoparticles (DSMNPs) were applied as an efficient adsorbent to retrieve the analyte-containing IL and LAS. Under the optimal extraction situations, good linearity of the approach was obtained in the concentration range from 10 to 1000 ng/mL for target analytes, and the preconcentration process was rapidly accomplished in 5 min. The limits of detection (LODs) based on a signal-to-noise ratio (S/N = 3) were ranged from 1.42 to 3.57 ng/mL with the relative standard deviations (RSDs) over the range of 1.84–3.56% (n = 5). The above-mentioned method was applied to the trace analysis of four PAEs including benzyl butyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di-n-butyl phthalate (DBP), and di-n-octyl phthalate (DNOP) in packaging milk samples, and recoveries were between 89.8 and 99.7%.     

Life by Digital

也许有一天.在我们的住宅里没有了独立存在的家具.也没有了明显的空间界线.而墙壁上会"长"出家具,让空间的流线更加飘逸自由……     

ZrB system by self-propagating

emperature synthesis (SHS) technique, and the effect of particle size of Zr powder on the SHS reaction in ZrB system was studied. The phase constituent of SHS product was investigated by X-ray diffraction analysis, a     

Magnetic Dummy Template Silica Sol–Gel Molecularly Imprinted Polymer Nanospheres as Magnetic Solid-Phase Extraction Material for the Selective and Sensitive Determination of Bisphenol A in Plastic Bottled Beverages

In this study, a core–shell magnetic dummy molecularly imprinted polymer (MDMIP) was prepared with a novel and simple method. The imprinting layer was synthesized directly on the surface of Fe₃O₄ by only one step, which avoided further modification on the exterior of magnetic core. 4,4′-Dihydroxybiphenyl (DDBP) was used as dummy template instead of bisphenol A (BPA) to eliminate the effect of template leakage on quantitative analysis. When used as solid-phase extraction sorbent, a rapid, sensitive, and accurate method for the simultaneous extraction, concentration, and determination of trace BPA in plastic bottled beverage samples by MDMIP-SPE coupled with high-performance liquid chromatography (HPLC) was developed. Advantages of such method may be counted as the mild working temperature during the synthesis, simplicity of extraction procedure, avoidance of leakage of template, time-saving, and high binding capacity and affinity. Several parameters affecting the extraction efficiency of the analytes including the sorbent mass, the pH of sample solution, the HAc percentage in the elute, and the desorption time were investigated. Under optimized conditions, the calibration graph was linear over the range of 11.4–4560 ng mL^?1 with the limit of detection of 0.083 ng L^?1. In addition, the higher enrichment factors (400-fold) and good recoveries (88.6–99.5%) with relative standard deviation (RSD) values less than 9.5% were achieved. Moreover, the developed extraction protocol simplified the process of traditional solid-phase extraction (SPE) provided the possibility for separation and enrichment of BPA from complicated food matrices.     

永不静止RANSOM by adidas Originals

加拿大街牌RANSOM，从户外风转型军事风，打出了一场转型胜仗。如今又在环保材料上做起文章，再一次带来晾喜。登陆中国后，RANSOM简洁休闲的风格倒是引来不少关注。     

10年企划 PUMA by MIHARAYASUHIRO

能够相交10年，已经是件不容易的事，更何况要握手合作达十个寒暑？日本设计师三原康裕（Mihara Yasuhiro）与PUMA彷佛就是天造地设的一对。1998年三原康裕（Mihara Yasuhiro）在东京开办售卖各种鞋款的专门店“SOSO MIHARA YASUHIRO”，凭其独门造鞋技术。     

Sunglasses by 5cm X mikli

太阳眼镜近年成为潮流和时尚界极其重要的配饰之一。其实原因很简单，这件架在鼻梁上的东西确实有其不可替代的作用。比如可以遮挡刺眼的阳光；比如可以盖住黑眼圈等等。如果发散开来，对于搭配衣服也起着非常重要的作用。再加上现在不少品牌在推出配饰时都会选择太阳眼镜作为主推，有多种的配色和款式，所以就会有更多的人去关注和佩戴，而且没有明显的年龄限制。[编者按]     

鬼脸 adidas Roster Mid by Mark Gonzales

adidas Coastal,其实就是找来世界各地极富盛名的与涂鸦艺术家合作的滑板联盟，将每个人用在书籍和报刊上的图片套用于系列设计之上，断Dennis Busenitz、Tim O＇Connor和Sieben之后，新一轮的合作轮到了adidas skate的灵魂人物Mark Gonzales.     

窝心钉——CONVERSE by JOHN VARVATOS

无论情侣、朋友还是工作伙伴也好，有些总是坚持如两条平行线，永远有着那么一点距离但是总是不能相交，而有些却每天都盼着对方能给予新惊喜和新鲜感，到底合作了数季的converse by John Varvatos还有没有新火花，新变化呢？看过以下三款鞋后可以给你一个肯定的答案：有!本次搞起了朋克和错觉。AS Studded用上很朋克的金属窝钉，加上刻意弄脏的中底，单从制作工艺来看已经同之前有了很大的变化，     

Preparation of Soy Peptides by Liquid Fermentation

Many kinds of microorganism can produce a mount of protease which subsequently hydrolysis the protein of the medium into peptides when they grow in protein containing liquid medium.In the present investigation,the conditions of preparing soybean peptides by liquid fermentation were studied,following results were obtained:(1)SPI is a nice nitrogen source and meanwhile an inducible factor of protease production;its concentration can be as high as 3%-4%.(2)Sucrose is the best carbon source;its concentration is 1%-4%.(3)Under the conditions of 28℃,initial pH6.0,inoculum size 4%,cell age 36hr and fermentation time 24hr-30hr,we can obtain soybean peptides or fermentation liquor with good flavor,its DH reaches 25%-30% and the yield rate can be as high as 75%.(4)Mass spectrograph indicate the MW of the fermentation liquid or the soybean peptides mainly distribute at about 4000Dal,these imply a promising prospect of industrial application of submerged fermentation in producing soybean peptides.     

LUVON by LIULU 向设计师品牌致敬

"中国第一夫人身着中国原创独立设计师品牌服装出访……中国第一夫人携中国原创品牌礼品赠送……中国第一夫人……"随着这样一则消息的发布,就像导火索一样,点燃了中国原创品牌的热潮,使得原本小众化的"独立设计师品牌"走进大众的视野,且促使时尚主流人士关注、追捧中国独立设计师品牌。     

GIVENCHY by RICCARDO TISCI捆绑玛丽珍

“在我人生最难穿的鞋之中,它是No.1!”香港明星黄伟文曾经这样说,这是他花了半小时穿鞋、半小时脱鞋后的第一手结论。