Owner: Chromatography URL:http://www.justchromatography.com/ Join Date: Sat, 28 Apr 2007 13:58:41 -0500 Rating:0 Site Description: Chromatography and Analytical Chemistry - from history and basic principles to the latest research news and concepts such as Nano HPLC and "Lab on a Chip" concepts. Site statistics:Click here
HPLC analysis of xanthones in mangosteen fruit 2007-04-28 16:00:59 During my frequent trips to south-east Asia, I alway enjoy a very peculiar, tropical fruit - mangosteen. It is one of the most praised of tropical fruits, and certainly the most esteemed fruit in the family Guttifera. The fruit is round and about 1.5 -2″ in diameter with a very dark purple smooth skin. It is better to open it with a knife by cutting around the middle completely through the rind, and lifting off the top half, which leaves the snow-white, juicy, soft segments exposed in the colorful “cup”–the bottom half of the rind. The fruit is exquisitely luscious and delicious, and it is by far my most favorite taste of all.
The rind of partially ripe fruits yields a polyhydroxy-xanthone also called ß-mangostin; whereas, fully ripe fruits contains the xanthones and various derivatives. Xanthones are unique chemical compounds composed of a tricyclic aromatic system with a variety of phenolic, methoxy, and isoprene substituents, giving rise to numerous derivatives.
Detection of explosives on skin in a few seconds 2007-04-27 18:05:27 A highly sensitive new method of testing explosives was developed by a group of scientists at Aston Labs - the research group of Professor R. Graham Cooks at Purdue University.
Single nanogram amounts of the explosives such as TNT (Trinitrotoluene), RDX (hexogen), HMX(octogen), PETN (penthrite) and their mixtures were detected and identified in a few seconds on the surface of human skin without any sample preparation by mass spectrometry sampling method called desorption electrospray ionization or DESI, a proprietary technology introduced by Dr. R. G. Cooks.
Desorption electrospray ionization (DESI) is carried out by directing electrosprayed charged droplets and ions of solvent onto the surface to be analyzed. The impact of the charged particles on the surface produces gaseous ions of material originally present on the surface that can be analyzed by mass spectrometer.
In this experiment, a solution of methanol and water with addition of sodium chloride was sprayed onto human skin, a Read more:Detection
Intelligence, iColumn, iPump and iDetector from Metrohm 2007-04-26 18:05:37
Metrohm, Ltd., a Swiss based company, recently introduced a new Ion Chromatography (IC) System - ProfIC.
Metrohm claims it as “the first professional IC system with intelligent system components:
Intelligence in the newly developed hardware of the 850 Professional IC
Intelligence in the MagIC Net™ software
Intelligence in the Metrosep iColumns.”
Wow… When I got to this part about intelligence in iColumns I burst into laugher. Is this a joke? Are they trying advertise this IC to teenagers or scientists? I can just picture some PR/Marketing guy from Metrohm trying to come up with a new name:
“Hmm, what’s the most popular and trendy name these days? Aha! Anything that has “i” in the front like iPod, iPhone and etc, so why don’t we name our first “intelligent” IC column - iColumn! ”
Don’t get me wrong, it sounds like a great system and I would trade it in a second for my old and dying Lachat IC that we use
Red Wine and Chromatography 2007-04-25 19:06:34 Dr. Richard Hoffman and his Erasmus student, Conny Johansson from University of Hertfordshire (UK) are using new chemistry laboratories to analyze a random selection of red wines to determine the levels of resveratrol which is a natural antioxidant found in red wine and red grape skins, known to protect against a range of illnesses and diseases including neurodegenerative diseases such as Parkinson’s or other dementias, cancer and heart disease and more recently documented for its role in extending lifespan.
According to Dr. Hoffman, although the health benefits of resveratrol found in red wine have been well documented, no one has systematically measured its levels in particular wines before. Dr. Hoffman and Mr. Johansson are using new state-of-the-art High Performance Liquid Chromatography (HPLC) and Liquid Chromatography Mass Spectrometery (LCMS) to separate and collect the compounds found in the wines.
They plant to work with wine suppliers and retailers so that they can pers Read more:Red Wine
So, what was happening in Tsvet’s “chromatographic column”? 2007-04-24 21:57:20 The green-leaf extract solution discolors as soon as it touches chalk powder, but the chalk becomes green. Molecules of all the components that make up chlorophyll are extracted from the leaf by precipitating on the surface of chalk’s particles. In general, uptaking of dissolved substances, vapors, or gases by the surface of solids or liquids is called adsorption by chemists, and the material that uptakes - adsorbent. All methods that separate mixtures, ultrafine purify compounds as well as analyze them are based on this phenomenon.
Captured by the surface of adsorbent’s solid body, molecules can transfer back into solution - eluent, and then again get adsorbed and so on, changing its state infinite number of times. Between the solvent (benzene in Tsvet’s experiments) and the adsorbent (chalk powder) there is an equilibrium: almost all of the molecules are on the surface of the chalk particles, but in the solvent there is almost none. But this “almost” i
Agilent 1200: Rapid Resolution LC System 2007-04-24 02:16:54 Another great LC system by Agilent provides up to 20 times faster analysis and 60 % higher resolution than conventional HPLC without sacrificing resolution, precision or sensitivity and while keeping system pressure at a minimum.
The 1200 RRLC ( RapidResolution
LC) has the same robustness and operates on the principles known from conventional HPLC instruments and methods. The 1200 works with column dimension from 1 to 4.6-mm ID, 10 to 300-mm length and particle sizes from 1.5 to 10 µm, and with flow rates from 0.05 to 5 mL/min which makes it the most universal LC on the market today that capable of throughput with up to 2000 samples per day!
Selected System
Specifications
Pump delay volume:
• Low delay volume configuration: 120 μL• Standard delay volume configuration: 600 – 800 μL
Flow rate range:
0.05 – 5 mL/min
Maximum pressure:
600 bar
Injection volumes:
0.1 – 100 μL without loop change or hardware modification, no overfill (drawn = in
Discovery of Chromatography 2007-04-23 05:42:07 Mikhail Tsvet got interested in the nature of chlorophyll - the substance that makes leaves green. The role of this substance in nature is enormous: with its help, the solar energy absorbed by a leaf is converted into chemical energy of organic compounds.
Professor Tsvet filled a glass tube with finely ground powder of pure chalk, damped it with benzene, and then poured over a little bit of chlorophyll solution extracted from a fresh leaf. The very top layer of the powder was, of course, immediately colored green, and then Tsvet proceeded to slowly, drop by drop, add benzene, into the tube filled with chalk. As colored layer got rinsed out with benzene, the green band started to move down the tube following the solvent. Then (this, in fact, was Tsvet’s remarkable discovery) the band started to slowly separate. There was a narrow yellow band that moved the slowest along the tube, it was preceded by the yellow-green one, and in front of it there was a wide, green-blue band, follow Read more:Discovery
Chromatography: a simple analysis of complex substances 2007-04-23 01:38:53
On May 14th 2007 we’ll celebrate 135th birth anniversary of an outstanding Russian chemist Mikhail Semyonovich Tsvet who discovered and, for the first time, applied essentially new method of analysis - chromatography. Nowadays, chromatography has become an indispensable method of separation and analysis of complex substances. With its help, scientists were able to figure out complex structures and compositions of protein compounds, isolate most of transuranium elements of periodic table, separate and purify antibiotics, vitamins, alkaloid and hormones. Chromatographic phenomena could be found in many natural geochemical processes such as soil formation and most of the ore deposits. And that’s why I am dedicating this blog entirely to chromatography!
World without wires 2007-05-01 06:19:11 What would you say if in a few years from now you would not need a power cord to charge your notebook or to deal with those annoying, tangled up cords behind your TV and stereo? Or would you imagine that your PDA or cell phone could be recharged remotely? I would say that it is something from a more distant future, but research scientists at the University of Tokyo have come up with a unique material that can transmit electrical energy to nearby devices without the need for direct contact. The system is based on a well know phenomenon discovered by Faraday in 1831 - electromagnetic induction - when electrical energy can be transmitted without a contact, just like some electric toothbrushes that recharge while sitting in a plastic charger.
The power-transmitting material is a plastic film with imprinted elements:
Japanese Researcher’s knowhow - a contactless position-sensing system that allows to direct power to wherever the appliance sits . It has a two-dimensional grid of Read more:World
Nano Liquid Chromatography 2007-04-30 06:01:22 Today there was a question posted by scholar on Yahoo! Answers:
Hi, I want some basic information on, what is nano Liquid
Chromatography??? & how it is different form normally used Liquid Chromatography (like HPLC or other LC Techniques)? What are its applications compared to HPLC? Or please provide me some reference web site or book on this topic.
I would like to answer this question in more elaborate way.
Nano HPLC is a relatively new development in chromatography world driven by recent advancements in proteomics that would require decreasing of inner diameter (ID) of liquid chromatography (LC) column to allow for a smaller sample amount and to increase sensitivity. The other demand for nano LC comes from the new field referred as “lab-on-a-chip” that would require “on-chip” liquid chromatography separation as part of other chip-based chemical analysis.
Presently the term “nano HPLC” is not well defined in analytical chemistry community and
Finding peanut in dark chocolate 2007-04-29 15:31:53 Food allergies are on the rise and one of the main culprits is a peanut. A study published in 2002 found that about 1.5% of children across the UK was allergic to peanuts, compared to 0.5% a decade earlier. In the US, around 0.6% have peanut or tree nut allergies such as walnuts, cashews, pistachios and Brazil nuts.
Not all peanut allergies cause severe symptoms, and many people are only mildly affected - in an itchy rash or mild stomach pain and diarrhea. But, there are those who suffer the life-threatening reaction of anaphylaxis, which is a severe, whole-body reaction that can constrict the airways and cause fainting, unconsciousness or collapse. There is also a third category of the most sensitive sufferers that, in some cases, cannot remain in the same room with anyone who is eating peanut-containing foods.
The peanut allergens are a group of eight proteins, known as Ara h 1 to Ara h 8, and generally enzyme-linked immunoassays (ELISA) is used to detect these proteins, using an a
Soy Milk, Good or Bad? HPLC vs CZE - Part 2 2007-05-03 15:07:44 Continued from “Soy Milk, Good or Bad? HPLC can tell - Part 1”
In their experiments, the scientists used a number of soy drinks from local stores:
8 soy milks
3 flavored soy drinks
2 soy drinks with added cereals
1 instant powdered soy drink
1 powdered soy shake
They also analyzed regular cow’s milk with added soy isoflavones. Sample preparation included hydrolysis for 23 hours with concentrated HCl (hydrochloric acid ) to break down the proteins, followed by solid-phase extraction to isolate furosine.
The HPLC method used a C8 column and the potassium chloride in aqueous acetic acid as a mobile phase, in a linear gradient. The retention time was slightly longer than 20 min and the identity of the peak was confirmed as furosine by mass spectrometry.
In the CZE method, furosine was detected by UV at 280 nm and had a migration time of 1.76 min in a separation capillary of effective length 40 cm.
When the soy beverages were analysed, about half had no detectable fur
Soy Milk, Good or Bad? HPLC can tell - Part 1 2007-05-02 06:52:24 Soybean drink, commonly known as “soy milk”, has become very popular in the West in the past decade. These days you can find a great selection of many different brands of soy milk products in virtually every supermarket. This popularity is largely due to the fact that soy milk is seen as a healthy product. Many of the health benefits of soy are derived from its isoflavones which, as illustrated by the more than 1700 scientific publications, may reduce heart disease risk, protect against prostate problems, improves bone health and other benefits. Soy is also a safe for individuals suffering from lactose intolerance, or who (like me) allergic to cow’s milk.
It is believed that soy milk invented in China about 164 BC by Liu An of the Han Dynasty who is also credited with the development of “Doufu” (soybean curd) which 900 years later spread to Japan where it is known as “tofu”. Traditional soy milk, a stable emulsion of oil, water and protein, i
Nano Light Bulbs for Your Shirt 2007-05-05 16:30:07 Every day scientists continue to surprises us with the new discoveries; however, the most noted and admired by the vast majority of folks as well as science professionals are the achievements and developments in the field of nanotechnology. We all get easily amused when we see the next “nano” research headline because the “nanotech world” is not yet fully understood or explored.
Recently Craighead Research Group at Corenll University reported their next “nano” breakthrough. They created a so-called “Nano-Lamp” - a microscopic collection of light-emitting fibers with dimensions of only a few hundred nanometers.
According to the research article published in “Nano Letters”, the scientists were able to create one of the smallest manmade source of light that world has ever seen. The light-emitting spots on the fibers measure less than 250 nm in diameter which makes this light source smaller than the wavelength of light that they Read more:Bulbs
, Shirt
Yahoo Answers: What chemicals can be detected using a Gas Chromatography? 2007-05-04 06:06:50 Today there was another question about chromatography on “Yahoo
! Answers” from naisy428:
What chemicals
can be detected using a Gas Chromatography?
Here is my very short, simplified answer. There are actually two types of Gas Chromatography - Gas-Solid and Gas-Liquid depending on the kind of column is used:
GSC (Gas-Solid Chromatography) allows to separate and hence detect low-molecular-mass gases such as air component (nitrogen, oxygen, CO2), hydrogen sulfide, carbon monoxide, and nitrogen oxides.
GLC (Gas-Liquid Chromatography) - this type is very widespread in all fields of science and that’s why when people say “GC” they usually refer to gas-liquid chromatography. This type of GC is mostly used to determine organic compounds such as hydrocarbons, polynuclear aromatics, fatty acids, alcohols, ethers, essential oils or any other volatile compound. What GC can detect greatly depends on the column and detector used. Generally speaking, GC is not suita Read more:Yahoo Answers
Yahoo Q&A: “What is the peak width in Chromatography?” 2007-05-08 15:37:19 This question was asked today by “Rambabu26 d” and it has been answered by three chromatography wizards.
Bullfrog21, who gave a short but precise answer:
Peak width is the distance on the graph between the two lowest points on either side of the peak. […]
A second answer came from, T0bl3rone who assumed that the question was about TLC (Thin Layer Chromatography) or perhaps never dealt with a modern column chromatography that gives results in a form of a plot of detector’s response over time - chromatogram : (more…)
Read more:Yahoo
CSI’s New Tool: Forensic Analysis of Gel Pens 2007-05-08 04:41:21 Here is another example of forensic application of HPLC that allows to classify and date the black gel pen ink entries on documents.
Gel pens first came out in 1984 in Japan and quickly became popular throughout the world due to their solid line, bold colors, and low cost. They are also regarded as environmentally friendly since the ink gel is water-based. The general design of a gel pen is similar to that of a ballpoint pen, however, the gel ink is different and consists of pigment suspended in a water-based gel. The pigments are typically copper phthalocyanine and iron oxides, and the gel is made up of water and biopolymers, such as Xanthan gum and tragacanth gum, as well as some types of polyacrylate thickeners.
The increasing popularity of gel pens has seen them used to sign many legal documents and as a direct result, they have also become the subject of forensic scrutiny in cases of suspected fraud. Several well-established methods exist for analyzing inks from ballpoint and f Read more:Forensic
, Analysis
, New Tool
Non-destructive Method To Detect Forgery 2007-05-07 02:59:54 The technique, developed by Graham Cooks at Purdue University, Indiana, and his colleagues, combines 2D molecular imaging with ambient Mass Spectrometry (MS).
Presently the majority of document analysis requires parts of the document to be cut up, extracted with solvent then run on chromatographic column followed by Mass Spectrometry (MS).
Cooks’ method uses DESI-MS (Desorption Electrospray Ionization Mass Spectrometry) under ambient conditions, where the analyte is electrosprayed with a solvent to generate charged droplets for MS analysis. This method greatly reduces the number of sample treatment steps and also only damages a smaller amount of document’s surface. The research group was able to use the technique to identify if and where handwritten text had been altered.
“The use of DESI and imaging DESI for the forensic analysis of inks represents an exciting new application of the technique” said Colin Creaser, professor of analytical chemistry at Nottingha Read more:Detect
Agilent’s “Lab on a Chip” HPLC/MS Video 2007-05-10 06:01:09 Almost two weeks ago there was a question regarding Nano HPLC technology that I attempted to answer and in that post I mentioned Agilent as one of the pioneers in the Nano LC field. Agilent’s “nano” workhorse is a 1200 Series HPLC-Chip/MS system, which uses microfluidics chip-based technology for nanospray LC/MS. Based on the HPLC-Chip and HPLC-Chip Cube MS interface, it provides “a new level of nanospray MS sensitivity, robustness, ease of use and reliability”. Here is Agilent’s sales video:
The HPLC-Chip integrates columns, connection capillaries,and nanospray emitter directly on the polymer chip surface eliminating peak dispersion and providing uncompromised chromatographic performance
Re-usable, integrated biocompatible HPLC-Chip designed for high sensitivity nanospray LC-MS.
HPLC-Chip Cube provides easy to use operation with automatic chip loading, solvent and sample delivery to the chip, high pressure switching of flows and automated ch
Super Jacket: cleans air, kills germs and does not have to be washed 2007-05-09 22:59:50 Assistant professor Juan Hinestroza and postdoctoral researcher Hong Dong from Cornell University created two types of fabric: one can prevent colds and flu and never needs washing, and another that destroys harmful gases and protects the wearer from smog and air pollution.
The “super” fabric is made by coating ordinary cotton with silver nanoparticles. First the fabric is positively charged using epoxy resins that induce positive ionization, then it gets simply dipped into a solution containing negatively charged silver particles of 10-20 nm in size that were synthesized in citric acid to hinder agglomeration. The silver particles adhere to cotton fibers creating a material that kills viruses and bacteria due to antibacterial properties of silver and thus reducing the need to wash. In addition, the small size of the particles prevents soiling and stains.
The use of palladium nanoparticles instead of silver ones, creates cotton that acts as a catalyst that’s able t Read more:Super
, Jacket
Happy Birthday Professor Tsvet! 2007-05-14 06:01:31 Today is 135th birthday anniversary of chromatography’s founding father Mikhail Tsvet and to celebrate his birthday I will be posting some interesting stories and facts from his life during the course of today.
Read more:Happy
, Birthday
, Happy Birthday
Iodized Table Salt 2007-05-14 01:37:12 Today I visited my mother and as she was preparing lunch she asked me if I would like iodized or regular table salt in my soup. I went with the regular one because I never feel quite comfortable when there are artificial additives in my food. I guess it is because I have a hard time trusting the QC (Quality Control) departments of the food industry as a opposed to pharmaceutical ones. Then later today I decided to do some little “research” to see what analytical methods are currently used in QC of table salt production. (more…)
Read more:Table
Meditation Helps to Pay Attention 2007-05-12 06:01:47 This synopsis was written by Rachel Jones on a very interesting research work: “Mental Training Affects Distribution of Limited Brain Resources” by Richard J. Davidson and his team where their findings demonstrate that meditative training can improve performance on a novel task that requires the trained attentional abilities.
So those who learn and study can add another tool to their arsenal - meditation - that should help reduce your current daily load of Nootropil.
Learning to Pay Attention
Our sensory system is constantly bombarded with inputs, but owing to the brain’s finite processing power, we are forced to pay attention to only a tiny proportion of these inputs at any given time. In a new study, Richard Davidson and colleagues report that intensive training in meditation can alter the way in which the brain allocates attentional resources to important stimuli, allowing people to improve their performance on a demanding visual task.
(more…)
Read more:Meditation
Liquids as Future Data Storage 2007-05-11 16:25:39 The researches inadvertently discovered that they can write and erase on the surface of liquids - the method that could one day be applied to high-density data storage, making templates for etching silicon chips (photolithography) and a variety of other materials applications.
Peter Licence at the University of Nottingham, UK, and his colleagues were using mass spectrometry (MS) as part of their ultra-high-vacuum research on liquids that contain only ions - ionic liquids. The experiment was carried out at -85oC when the ionic liquid of interest - 1-ethyl-3-methylimidazolium ethylsulfate is in a frozen state. The chemists noticed that the particle beam from the spectrometer created a pattern of charge on the surface of a frozen ionic liquid. When ionic liquids solidify they loose their conductivity and become insulators, but when the ion beam bombards the solid sample surface it knocks electrons from the material, leaving positively charged lines that frozen liquid cannot dissipate. Read more:Future
Single-molecule mass spectrometry 2007-05-17 05:36:18 John J. Kasianowicz from NIST and his colleagues created a 2D method for mass spectrometry capable of a single-molecule
analysis based on the interaction between a nanometer-scale pore and analytes. The method is a “nano” version of Wallace Coulter patented technique that detects particles suspended in solution by driving them through a capillary which is widely used to count and size red blood cells and platelets. (more…)
Journalist’s definition of Chromatography 2007-05-15 19:58:22 The AP released the highlights of the first day of Floyd Landis arbitration hearing in Malibu who is the first Tour de France winner in its 104-year history to be stripped of his title because he tested positive for steroids. What caught my attention and really made me laugh was The Mercury News definition of chromatography :
Chromatography is the process labs use to insert gas into a urine sample to separate out different compounds, which helps determine whether someone used steroids.
Read more:Journalist
Chromatogram on the ceiling 2007-05-14 18:23:39 Series: 135th BirthdayHappy Birthday Professor Tsvet!Chromatogram on the ceiling Imagine yourself in a rather large and almost empty room with an iron bed in the corner. Autumn. Cold. Gloomy. It has been raining for days and the roof is leaking. In the opposite corner on the ceiling the wet spot is slowly spreading; the rain drops are falling into the bucket on the floor. You cannot complain to a landlord - last month’s rent has not been been paid. All that’s left is to watch strange patterns forming on the ceiling. And if you look closely, you can see remarkable things - traceries made of beautiful, and quite bright color rings - green-blue (vitriol?), brown (metal roof rust?), pink (old paint?). The bands of different coloring are sharply separated from each other and form intricate figures. Nowadays it is hard to see something like this. New technologies - concrete blocks, leak-proof roofs, synthetic materials, and no chalk-based plaster and vitriol. But in the past&hell
A glass microchip that spun controversy 2007-05-19 01:05:15 Series: Lab on a Chip and MSProteomics made fasterA glass microchip that spun controversy Shortly after I posted “Proteomics made faster” I saw another research article published on the topic. Now, Detlev Belder and colleagues at the University of Regensburg, have developed a glass microchip that directly couples electrophoretic separation techniques with the electrospray process. As per “Chemistry World“:
Chemists in Germany have created a glass microchip that combines microfluidic channels with a nanospray emitter for electrospray ionization mass spectrometry. The device enables the coupling of microchip electrophoresis and mass spectrometry with nanolitre samples and no dead volume.
The group developed a glass chip on which the electrophoresis channels lead directly to the integrated nanospray nozzle. “Glass chips are more suitable than silicon especially for electrophoresis, but also for many chemical applications,” Belder commented.
The staff o
Proteomics made faster 2007-05-19 00:40:42 Series: Lab on a Chip and MSProteomics made fasterA glass microchip that spun controversy The large-scale studies of structure and function of proteins (proteomics) are performed using a variety of analytical techniques from two-dimensional gel electrophoresis, immunoaffinity chromatography to tandem and MALDI-TOF mass spectrometry. The words “large-scale” in proteomics definition refers to the fact that the number of proteins that need to be evaluated is enormous. For example, the human body may contain more than 2 million proteins, each having different functions, and that’s why there is a great pressure from proteomics research to increase the throughput of protein analysis and that’s where lab on a chip technology comes into play. But so far we only have a handful of analytical processes that have been 100% transferred onto a chip, and most of what is being used now is a hybrid system. (more…)
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