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
Quantum-dot-Sensitized Nanowire Solar Cell 2007-05-18 01:39:27 Yesterday “Nano Letters” released an article - “Photosensitization of ZnO Nanowires with CdSe Quantum Dots for Photovoltaic Devices” by Eray S. Aydil and et al. (DOI: 10.1021/nl070430o). I could not read the entire article because I am not a subscriber and don’t want to spend $25, but judging by the abstract the research team’s quantum-dot-sensitized nanowire solar cells were able to produce 1 to 2 mA/cm2 and open-circuit voltages of 0.5-0.6 V under simulated sunlight with 50-60% efficiency which is extremely impressive!
Read more:Solar
Nanoglue for jet engines 2007-05-17 23:03:51 The research group from Rensselaer Polytechnic Institute (NY) led by Ganapathiraman Ramanath was able to glue two materials together a one nanometer-high layer of polymer chains. This thin but very strong nanoglue could become a useful adhesive in computer chips and other materials devices where thicker layers wouldn’t fit. One other unique property of the glue is that it can withstands temperatures up to 700°C so it could be used to hold paint on hot surfaces such as the inside of jet engines
. (more…)
13-year-old CEO Teaches Kids Chemistry 2007-05-22 08:50:57 “Create. Combat. Conquer.”- the slogan of Silicon Valley gaming startup “Elementeo” and its 13-year old founder and chief executive, Anshul Samar. “We inject fun into education,” the fast talking entrepreneur confidently proclaimed, promoting his new fantasy role playing board game which he hopes will change the way kids learn chemistry. Here is a video of a young entrepreneur:
One Scientist, no Scientist 2007-05-21 19:43:33 “Single man in a field is not a warrior” is a Russian proverb that has proved to be true when it comes to science research according to Brian Uzzi and colleagues from Northwestern Institute on Complexity that authored “The Increasing Dominance of Teams in Production of Knowledge” published in the May 18th issue of “Science” (vol 316, p. 1036).
Scientists examined almost 20 million research papers published in the last 50 years as well as more than 2 million patents and established that teams of scientists are increasingly dominating solo authors in the production of knowledge and that research is increasingly done in teams across almost all fields. (more…)
Colorgram 2007-05-20 17:41:27 Series: 135th BirthdayHappy Birthday Professor Tsvet!Chromatogram on the ceilingColorgram So, Mikhail Tsvet was trying to solve the separation problem of the green leaf pigments. He took a glass cylinder, filled it with chalk powder, and on the top layer poured a little bit of the alcohol extract of leaves. The extract was brownish-green, and the top layer of chalk column became also the same color.
Then Mikhail Semyonovich started to drop by drop add pure alcohol to the top of the chalk column. And with each coming drop the alcohol dissolved the pigments off the chalk particles and moved down the cylinder. As a result, in the glass cylinder filled with chalk there were uniformly colored bands of pure substances. It was beautiful. The bright-green band and the yellowish-green one were the two kinds of chlorophyll, and the yellow-orange one was from carotenoids.
Tsvet named this picture - “chromatogram”. If you know Russian, it’s hard to hold your smile back: Tsvet (
Imploding Bubbles At Work 2007-05-24 23:25:15 Scientists of the University of Twente (The Netherlands) succeed in speeding up the fluid flow in a micro channel using tiny and rapidly imploding gas bubbles that also provide a new way of mixing fluids within a lab-on-a-chip, without the need of complicated external components. The scientists led by Dr. Claus-Dieter Ohl of the MESA+ Institute for Nanotechnology present their results in a coming June 2007 edition of Physical Review Letters.
“Controlled cavitation” is the basis for the new technique: using a laser, a bubble is induced in the micro channel, by local heating and low pressure. This bubble has a short life: it rapidly implodes caused by the higher pressure in the channel. This causes the fluid flow to go up to 20 meters per second. In addition, a jet is formed near a channel wall together with tiny bubbles around which creates a vortex - an ideal way of mixing fluids.
The bubble expands and collapses in a complex geometry. Here, two feeding capillaries connec Read more:Bubbles
Bilberry Adulteration Using Amaranth exposed by HPLC 2007-05-23 12:05:37 How many of you out there picked or even ate fresh bilberries? Probably not too many, unless you are from Northern Europe, Russia, or the Rocky Mountains of the US. The rest of us find bilberries in the form of purple capsules in dietary supplements.
Bilberry is small shrub to a one foot in height with sweet, plump blue-black berries with deep purple flesh that taste somewhat similar to blueberries but slightly tarter and much more aromatic. Bilberry is one of my favorite berry, and if I happen to be in Europe in July, I can never resist bilberry vareniki (East European stuffed dumplings) in dark-purple bilberry sauce.
Bilberry fruits have been used as herbal medicine since the Middle Ages as treatment for various intestinal conditions, thyroid fever, and a number of infections. In the modern European herbal medicine, bilberry fruit extracts are used to enhance poor micro-circulation, including eye conditions such as night-blindness and diabetic retinopathy. In the 90s, several la Read more:exposed
How does High Performance Liquid Chromatography (HPLC) measures HbA1c? 2007-05-27 13:56:56 A question from Yahoo! Answers:
Can anyone explain how does HPLC measures HbA1c? What exactly is HPLC?
Let’s start with the last part of the question - “What exactly is HPLC?”
HPLC or High PerformanceLiquid
Chromatography in simple terms is a form of column chromatography used frequently in biochemistry and analytical chemistry to separate components of a mixture followed by identification and quantitation of each component. In case of HPLC analysis of glycosylated hemoglobin (HbA1c) , the “mixture” is a blood plasma sample.
“how does HPLC measures HbA1c?”
The blood plasma components, including HbA1c, get separated due to a variety of chemical interactions between plasma molecules and the column of the HPLC instrument. The levels of detected substances are plotted in the form of a series of peaks . The area under the peak is proportional to the amount of analyte present and by calculating the area of the peak using the mathematical functio
Nano Light Bulbs for Your Shirt 2007-05-05 09:30:07 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? 2007-05-03 23:06:50 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
Soy Milk, Good or Bad? HPLC vs CZE - Part 2 2007-05-03 08:07:44 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 23 hour hydrolysis with concentrated HCl (hydrochloric acid ) to break down the proteins, followed by a 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 with a linear gradient. The retention time was a bit over 20 min and the identity of the peak was confirmed as furosine by MS (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 analyzed, about half had no detectable furosine,
Soy Milk, Good or Bad? HPLC can tell - Part 1 2007-05-01 23:52:24 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
Quick and Simple C-C Link 2007-05-31 08:58:41 For those of you who are into organic synthesis. May 25th issue of Science published a paper by David R. Stuart and Keith Fagnou from University of Ottawa (Canada) - “The Catalytic Cross-Coupling of Unactivated Arenes”. They report that aromatic compounds can be coupled without having to preactivate the reactants.
This method employs palladium and a copper oxidant as a catalyst system to create C-C (carbon–carbon) bonds between benzene and two-ringed N-acetylindoles. Arene cross-coupling reactions have previously required several steps, with the starting materials first being converted into more reactive analogues. In the new scheme, the catalyst activates a carbon–hydrogen bond on the indole, making it reactive enough to form a bond with one of the benzene’s carbon atoms. The method is more efficient and generates less waste than other approaches.
Science 25 May 2007:
Vol. 316. no. 5828, pp. 1172 - 1175
DOI: 10.1126/science.1141956
Read more:Quick
, Simple
Lab on a “keychain” detects nano amount of airborne pollutants 2007-05-29 13:05:24 A breakthrough patent awarded to a New Jersey Institute of Technology (NJIT) researcher will enable manufacturers to create a device to detect miniscule amounts of airborne pollutants. Using computer chip technology, Somenath Mitra, PhD, professor and chair of NJIT’s Department of Chemistry and Environmental Sciences, has developed and patented what could eventually become a simple keychain device to detect tiny, though potentially lethal, amounts of airborne carcinogens.
(more…)
Touchy Silicon 2007-06-04 10:55:39 The first systematic study of a new group of explosives has concluded that the materials are so shock sensitive — apt to detonate if struck or heated — that the legendarily touchy nitroglycerin seems a pillar of stability by comparison. Conducted by Thomas M. Klapötke and colleagues in Germany. (more…)
Read more:Touchy
, Silicon
Traditional Chinese Meds on GC/MS 2007-06-02 19:18:45 A few years back during my 3 month trip to China I remember noticing enormous number of pharmacies that sold traditional Chinese
medicine. Everywhere I went in China they looked more or less the same just like an old-fashion pharmacy of the 1920s here in the West with its wooden drawers and cabinets full of dried herbs, flowers, insects, animal body parts, and other things that were truly scary looking. The “prescriptions” are filled on the spot by grounding ingredients in a traditional stone mortar and pestle.
Traditional
Chinese medicine or TCM, being natural materials, appeal to many people, because they are believed to have high activity, low toxicity, and rarely cause complications. This growing popularity drives the research of TCM in China especially in the field of analytical chemistry in order to control the quality of medicine. (more…)
Read more:Traditional Chinese
Recent applications in nanoliquid chromatography 2007-06-01 16:21:28 A review was published yesterday in “Journal of Separation Science” by a group of Italian researchers. So far all I have is abstract:
Since its first introduction by Karlsson and Novotny in 1988 nano-LC has emerged as a complementary and/or competitive separation method to conventional HPLC, offering several advantages such as higher efficiency, ability to work with minute sample sizes and lower consumption of mobile phases, and better compatibility with MS, etc. Although its use was not so extended initially, in the last years new and interesting applications have appeared which deserve to be carefully considered. The aim of this review is therefore to provide an updated and critical survey of different nano-LC applications in analytical chemistry.
It is hard to imagine that Nano-LCs are almost 20 years old and yet most labs don’t have them. Anyway, this review looks very promising and as soon as I get my hands on the full text I will blab more.
DOI: 10.1002/jssc. Read more:Recent
Non-Radiative Wireless Power - WiTricity 2007-06-07 12:59:16 A month ago I wrote a post “World Without Wires” about the unique material developed by Japanese scientists that can transmit electrical energy to nearby devices without the need for direct contact. Now in today’s issue of Science magazine, an MIT research team led by Prof. Marin Soljacic reported its version of the “world without wires” - “Wireless
Power Transfer via Strongly Coupled Magnetic Resonances“.
The team was able to wirelessly transfer power to a 60W light bulb from 7 feet away with 40% efficiency but unlike the Japanese method, it neither involves the pentacene based organic transistors, nor the magnetic induction. (more…)
electromagnetic induction, electromagnetic radiation, nikola tesla, organic transistors, wireless electricity, WiTricity
Corundum on Rails 2007-06-06 16:14:21 Ruby is a relatively rare, red colored gemstone and a variety of corundum (Al2O3) with traces of hexavalent chromium that’s responsible for ruby’s rich red color. The best, dark colored rubies are from West Mogok, Myanmar (Mandalay Division).
However, that’s not ruby that I would like to write about. Today I’ve embarked on a new journey for me. I am learning Ruby on Rails, a new and promising programming language Ruby with the framework - Rails. I am not a programmer but I wanted to learn something new and something other than chemistry, so for the reasons yet to be determined I decided to peruse a programming language, specifically something that can be used to create web applications, like this Wordpress blog . So now I have to see where I can start, I am sure there are tutorials on the Web.
corundum, myanmar, ruby, ruby on rails
Where is Chromatography? 2007-06-09 20:01:01 Today I received an e-mail from an unhappy reader where I am being mercilessly criticized for misleading the visitors to my blog.
Mr. X is rightfully accusing me for not staying focused on the topic of “just chromatography” and that I spend too much time on nanotechnology and things like witricity. What can I say in my defense? Not much, I am guilty. But how can I not write about the exciting discoveries and knowhows such as wireless power transfers, nano light bulbs, or laser induced imploding bubbles?!
Organic Oxygen 2007-06-12 07:29:49 A simple, cheap treatment using just oxygen could allow organic produce growers to store their crops for longer and go a long way towards reducing the price of organic fruit and vegetables.
I admit that I am into organic produce but mostly because it tastes better and fresher than the conventionally grown fruits and vegetables and not because I am a health freak. The big downside is the price. Currently I pay around twice as much for organic. This price difference comes from the large losses that organically grown crops sustain during storage. Conventional produce can be treated with inexpensive chemicals to aid preservation, but these cannot be used for organic produce. (more…)
organic produce, scald Read more:Organic
, Oxygen
Rocky Mountain Spotted Fever 2007-06-11 12:25:47 Today, it has been 3 years since I recovered from RockyMountain
Spotted Fever
or RMSF - a disease caused by Rickettsia rickettsii, a species of bacteria that is spread by hard ticks. On one hand, it is kind of cool that I had contracted a relatively rare and almost exotic disease (only ~800 reported cases per year), on the other, I had a very good chance of dying (>30%) because I was never treated for RMSF with antibiotics. (more…)
disease, ELISA, PCR, Rickettsia, rickettsii, rmsf, rocky mountain spotted fever, ticks Read more:Rocky Mountain
From Switzerland to Russia 2007-06-14 23:01:49 Series: 135th BirthdayHappy Birthday Professor Tsvet!Chromatogram on the ceilingColorgramFrom Switzerland
to Russia
This is the next post from the series dedicated to 135th birthday anniversary of Prof. Tsvet, the chromatography’s founder.
Today, the application of the principle of a chromatographic substance separation is the foundation of many breakthroughs in science and technology. The analysis of the amino acid and nucleotide sequence in proteins and nucleic acids, the isolation and purification of antibiotics and the variety of other substances are all based on the chromatographic separation.
The same principle is employed in the separation of radioactive isotopes and, hence, is used in the making of nuclear weapons and nuclear power plants…
People observed “substance separation” on leaky ceilings many times before Tsvet. So, why was he able to turn these observations into a powerful modern method of substance separation? (more…)
geneva university,
Toxic Waste Eating Bacteria 2007-06-14 13:00:10 New research on sulfate-reducing bacteria may offer good news for bioremediation efforts to clean up acid mine drainages and other environments with high levels of harmful metals.
Sulfate-reducing bacteria is known to extract metal dissolved in anoxic waters and by isolating it into nanoscale particles. But, the tiny size of these particles (2-6 nm) makes them highly mobile and under the right conditions they can quickly redissolve.
Previous research work showed that some organics can promote aggregation of the nanoparticles which induces settling and thus decreased their solubility. John Moreau and colleagues hypothesized that natural organic matter contributes to the formation of densely aggregated nanoparticulate zinc sulfide (ZnS) spheroids.
The research team studied biofilms of sulfate-reducing bacteria collected from a flooded lead and zinc mine in Wisconsin. They report that metal-sulfide nanoparticles produced by these bacteria form aggregates that contain trapped metal-bind Read more:Bacteria
Plastic that grows in the field 2007-06-14 12:59:29 A chromium catalyst is the key to efficiently converting glucose to a chemical feedstock with potential to replace many uses of crude oil including pharmaceuticals, cosmetics and plastics, scientists from Pacific Northwest National Laboratory report. As the world tries to emancipate itself from its oil addiction, researchers are seeking a clean, efficient and cost effective process that uses renewable biomass.
Hydroxymethylfurfural, or “HMF,” is a promising compound which is conventionally prepared from fructose using acid catalysts which, unfortunately, causes various side reactions, significantly increasing the cost of product purification.
Haibo Zhao and coauthors converted fructose and glucose to HMF in acid-free conditions by experimenting with 19 different metal halide catalysts such as CrCl2 (chromium (II) chloride), CuCl2 (copper (II) chloride), VCl2 (vanadium (II) chloride) in a sugar-solubilizing ionic liquid solvent - 1-alkyl-3-methylimidazolium chloride.
Tw Read more:Plastic
HPLC for Pharmaceutical Scientists 2007-06-20 10:37:14 “HPLC for Pharmaceutical
Scientists” is a new hardcover book edited by Yuri V. Kazakevich and Rosario LoBrutto with a price tag of $159 at Amazon.
This is an excellent book for both novice and experienced pharmaceutical chemists that provides a unified approach to HPLC with a balanced treatment of the theory and practice of HPLC in the pharmaceutical industry.
The book spells out the role of HPLC throughout drug development process from drug discovery to quality control and manufacturing and gives detailed specifics of HPLC application in each stage of drug development.
The text also covers the latest advancements and trends in hyphenated and specialized HPLC techniques (LC-MS, LC-NMR, Preparative HPLC, High temperature HPLC, high pressure liquid chromatography).
Here is a detailed review by Ira Krul from Northeastern University. (more…)
chromatographic, chromatography, GC, HPLC, LCMS, MS
Chinese Meds are Safe 2007-06-18 08:00:37 …well, the prescription ones at least. With Chinese
manufacturers considering to increase exports of drug ingredients and perhaps even begin shipping finished drug products to the United States, an article “Trusting medicine from China: Close FDA scrutiny of Chinese pharmaceutical ingredients extends only to those for prescription drugs” in Chemical & Engineering News (C&EN) questions allegations that foreign-made ingredients often are manufactured in factories that have never been inspected by the U. S. Food and Drug Administration (FDA). (more…)
china, chinese manufacturers, fda, TCM
Definition of Nano Liquid Chromatography 2007-06-17 23:09:43 Nano Liquid
ChromatographyNano Liquid Chromatography - ReloadedDefinition
of Nano Liquid Chromatography It is interesting to note that 20 years later there is still no clear definition of nano-LC. Due to a relatively large size of the columns used in nano-HPLC (10-140 μm), the method does not fall within the realm of the conventional definition of nanotechnology - “the control of matter on a scale smaller than 1 micrometre”.
However, most researches subscribe to the view expressed in the article “Instrumental Requirements for Nanoscale Liquid Chromatography” (DOI: 10.1021/ac9508964). The authors suggested the definition based on the flow rate range rather than the inner diameter of the tubing or its material. They proposed that the liquid chromatography method that uses packed microcolumns with 10-150 μm ID and flow rates of 10-1000 nL/min to be classified as nano-LC.
Names and Definitions for HPLC Techniques
Desciption
ID
Flow Rate
Nano HP
Nano Liquid Chromatography - Reloaded 2007-06-17 14:08:21 Nano Liquid
ChromatographyNano Liquid Chromatography - Reloaded
Definition of Nano Liquid Chromatography Thanks to one of the readers of this blog - Farooq, I now have the full text of an excellent, 21-page review by the researches from Rome and Spain entitled “Recent applications in nanoliquid chromatography” (DOI 10.1002/jssc.200700061).
Two months ago, I did a small article about nano liquid chromatography to answer a question posted on Yahoo Answers but after reading “Recent applications in nanoliquid chromatography” I wanted to revisit the topic in more depth, so I think I am going to make this post into a series - “Nano Liquid Chromatography”
Introduction
“Nano” has recently become a very trendy word in science and technology and most of us think of nanotechnology as something very modern and new, so it is hard to imagine that nano HPLC method emerged almost 20 years ago.
In 1988 Karl Karlsson and Milos Novotny published a paper &l
Translational vs Vibrational 2007-06-21 13:00:35 Has anyone seen today’s issue of Science? There is a research paper by Shannon Yan and colleagues “Do Vibrational Excitations of CHD3 Preferentially Promote Reactivity Toward the Chlorine Atom?” I had a difficult time following the authors - physical-molecular chemistry is not my strongest field, but nevertheless …
The study shows the energy of the moving molecules can unexpectedly promote a chemical reaction as effectively as the energy from within the chemical bonds. Until now, there has been a general assumption characterized as the Polanyi rules that the energy dynamics of reactions of small molecules with two and three atoms were simple - the vibrational energy of the bonds determines reactivity. However, a series of precisely controlled molecular collision experiments now challenges this model.
The P. Chem. scientist discovered that when CHD3 collides with Cl atoms to form CD3 and HCl, translational energy (produced by the movement of molecules in re
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