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Evaporating solvent is one of those everyday lab tasks that feels like it should be simple. But when you’re working with unstable, moisture-sensitive, or heat labile compounds, “set it and forget it” ...
Acrylamide extraction and analysis can be difficult. The primary challenge is balancing efficient extraction from a complex matrix with effective removal of background interferences before analysis, w...
Summary Automation of LC-MS/MS sample preparation enables reliable and reproducible analysis of both cortisol in urine and SDMA in serum. By successfully transferring SLE and PPT workflows to the Biot...
In the rapidly evolving world of oligonucleotide therapeutics, researchers are constantly faced with challenges to achieve consistent, high sensitivity results across different sample matrices without...
Environmental laboratories analyzing contaminated soils, groundwater, and wastewater face a common challenge: polar matrix interferences that compromise accurate hydrocarbon quantitation.
The increasing demand for peptide therapeutics highlights the urgent need for green peptide synthesis to minimize environmental impact. DMF, a widely used solvent in solid-phase peptide synthesis (SPP...
Removing solvent from purified products or from stored stock solutions is a major part of the organic synthetic workflow. Additionally, this dry down might be used while performing solubility experime...
Accurate environmental testing for petroleum hydrocarbons is essential, particularly when utilizing EPH (Extractable Petroleum Hydrocarbons) Fractionation. This analytical technique divides petroleum ...
Pharmaceuticals in the environment Pharmaceuticals are indispensable in modern healthcare, consumed daily in vast quantities for both prophylactic and therapeutic purposes. After use, many active phar...
Monitoring stress and hormonal changes during pregnancy is essential for understanding maternal and fetal health, but traditional sampling methods can be invasive and limited in scope. A recent study ...
If you’re responsible for testing acrylamide in food samples, you already know the obstacles that come with analyzing this compound. Analysis can be difficult in general if there are background interf...
Per- and polyfluoroalkyl substances (PFAS) have become a global focus in environmental analysis. With this attention comes the need for reliable, efficient sample preparation methods. The U.S. EPA has...
Per- and polyfluoroalkyl substances (PFAS) are a highly persistent group of synthetic chemicals that can be toxic to humans through bioaccumulation, gradual build up over time. In fact, toxicological ...
If you have experience testing food processing biproducts such as acrylamide, then you already know all the challenges that come with the territory. Acrylamide, a probable carcinogen formed during hig...
Petroleum-based products play a pivotal role in our daily lives, serving as fuels, lubricants, and raw materials for countless industries. However, with their widespread use comes the potential for en...
Gene therapy is on the brink of revolutionizing biomedical research and therapeutic sciences, driven by the promise of preventing disease progression and offering long-term cures. While the number of ...
In recent years, gene therapy has emerged as a ground-breaking approach to tackling various genetic disorders and diseases. By manipulating genetic information using vector-based strategies, researche...
Sterols are lipids in our bodies that help maintain the integrity of cell membranes and are transported by lipoproteins in the bloodstream. They exist as free sterols and steryl esters (sterols combin...
Evaporation is a key step in the sample preparation workflow, either to concentrate analyte of interest or to exchange a solvent for one more compatible with the subsequent analytical technique. Sampl...
Pesticide residues in food, even at low levels, pose significant health risks and have been linked to chronic illnesses and developmental issues. To protect consumers, regulatory authorities closely m...
Extractable Petroleum Hydrocarbons (EPH) may be invisible, but their impact on the environment is tangible. Through advanced monitoring techniques and a robust regulatory framework, we strive to strik...
In the world of science, there are always new topics and compounds that are discovered, but not all of them get much publicity. One of these is acrylamide. Now you’re probably saying to yourself, “wha...
Often the question arises asking how can I extract both acids and bases with the same Supported Liquid Extraction (SLE) procedure. Is this possible? And how?
Unbiased peptide screening technologies have evolved, improved and recently gained acceptance by the community as strategies for identifying new lead compounds against old targets with in novel chemic...
Preparative HPLC and flash chromatography are two of the most utilized techniques for purifying molecules post synthesis. To monitor sample purity and elution times, detection techniques such as UV/UV...
Evaporative light-scattering detection (ELSD) is an effective tool for detecting compounds with minimal to no UV absorbance. ELS detectors convert the column effluent into an aerosol by adding heated ...
I like working with natural products, at least from a chromatography perspective. The sheer breadth of compounds extractable from a plant makes separations a challenge but overcoming that challenge wi...
ELSD, or evaporative light scattering detector, is an accessory item available for many commercially available flash chromatography systems. It is typically used to detect compounds that are UV transp...
Cl-trityl resin can be tricky to use not only from an amino acid loading perspective, but one must also consider the highly labile linkage to the solid support1. This lability is advantageous in insta...
Dry loading crude reaction mixtures can dramatically improve purification results. This is a topic I have blogged about several times and is important enough to discuss again.
Are you currently or have you ever had an issue where your chromatographic trace shows a sine-wave pattern while a compound is eluting, Figure 1? If so, there are several causes, and solutions, for th...
The answer to this question is absolutely yes. The choice of organic solvent can impact your reversed phase flash purification results just as organic solvent selection impacts normal phase results.
If you use automated flash chromatography you may have a system than can have four solvents attached to it. In fact, most flash chromatography systems are designed to have as many as four solvents ava...
Finding the right affinity tag can be a challenging task for many. The process requires not only an understanding of your protein but also the downstream process of your purification. You need to find...
Head-to-tail cyclization of peptides is being used in drug development as yet another way to probe how constraining peptide sequence structure in solution can improve pharmacokinetics and target speci...
We all know the adage “Time is Money”. It is particularly true in pharma where the timeline to get a pharmaceutical product to market can take 10+ years and cost billions of dollars. With this as the ...
The big question…what affects cyclization efficiency? This is what I have been trying to answer over the course of the last few experiments, especially when it comes to head-to-tail macrocycles. I hav...
With the increasing use of reversed phase flash chromatography in medicinal chemistry and organic synthesis labs comes the desire to speed up and make these purifications more time and solvent efficie...
Have you ever had a purified reaction product, which should be white, retain color after purification? If so, what did you do to remove it?
With the increased use of reversed phase flash chromatography for reaction mixture purification comes a lot of questions since many chemists are not as familiar with this technique as they are with no...
Flash chromatography is a great tool to purify reaction mixtures and natural product extracts. Modern flash chromatography instrumentation incorporates UV detectors to see eluting compounds and trigge...
The dynamics of solid phase peptide synthesis at the resin surface makes it particularly difficult to create head to tail macrocycles. Dimerization, steric hinderance, and C-terminal access all reduce...
Silica dissolution in methanol is a concern many chemists have. Over my career I have heard that complaint probably hundreds of times which invariably leads to the question - how much methanol can I u...
Flash chromatography with real-time UV detection and fractionation is the primary tool of chemists for isolating synthetic compounds. However, many commonly used flash chromatography solvents (ethyl a...
What is bead mill homogenization? Well, first we need to understand that homogenization is the process of making something uniform. So, what is bead mill homogenization? Bead mill homogenization is a ...
If you synthesize organic compounds you likely have encountered situations where traditional silica or even reversed-phase chromatography just does not get the job done. Co-elution, peak tailing, yiel...
Macrocyclization of peptides has arisen as a new strategy to create proteolytically stable, membrane permeable drug candidates while maintaining target specificity. To perform this cyclization, lactam...
For chemists trying to purify polar compound mixtures, optimizing the chromatography can be very challenging. When hexane (or heptane) with ethyl acetate and a silica column fails to effectively purif...
We know that compounds can be acidic, basic and neutral. Looking at pKas and functional groups can help us understand the best approach for SPE selection and workflow. Let’s take a look at the compoun...
We know that compounds can be acidic, basic and neutral. Looking at pKas and functional groups can help us understand the best approach for SPE selection. Let’s take a look at the compound, methylmalo...
Virtually all automated flash chromatography systems today contain a diode-array UV or UV-vis detector (DAD). This type of UV detector offers multiple benefits over monochromatic UV detectors includin...
We know that compounds can be acidic, basic, and neutral. Looking at pKa and functional groups can help us further in selecting the right SPE sorbent and better understanding how it works with our ana...
Polar reaction mixtures can be a real challenge to purify with flash chromatography. Traditional normal-phase flash requires toxic dichloromethane (DCM) or chloroform with methanol for these types of ...
You may have already read the previous blogs about QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) extraction and cleanup, but, if you have quite a few different matrix interferences or analyte...
In unconventional assays, it may be difficult to find an effective purification method to separate your biomolecule from your complex sample. With factors such as specificity, selectivity, stability, ...
We know that compounds can be acidic, basic, and neutral. Looking at pKas and functional groups can help us understand the best approach and steps for SPE selection and workflow. Let’s look at the com...
Silica flash columns are the most frequently used to purify reaction mixtures. Prepacked columns are available from a vast number of vendors as is the silica itself for those wishing to pack their own...
In synthetic organic chemistry, post-reaction work-up using solvent extraction is almost routine. Solvent-solvent extractions using immiscible solvents can remove impurities from the product prior to ...
Flash chromatography is a purification technique that, by its name, is designed to be fast. Faster than open column chromatography and faster than prep HPLC. Flash chromatography is faster due to the ...
Understanding the properties of different SPE sorbents can be confusing, refer to selecting sorbent chemistries for a refresher. But what happens at each step of these different SPE sorbents specifica...
An interesting question for synthesis chemists as the need for reversed-phase flash chromatography for both intermediates and final compounds increases. Historically, normal-phase flash chromatography...
When choosing the stationary phase for SPE understanding the functionality of your target molecule is of critical importance. In order to select the correct SPE chemistry we need to understand how fun...
For many chemists, one flash chromatography column is the same as another and only price is considered. This is true for both silica and reversed-phase (C18). However, since there are differences betw...
When it comes to environmental sample testing, there’s no shortage of the types of toxic substances you can detect utilizing liquid chromatography with tandem mass spectrometry (LC-MS/MS). At the time...
Flash chromatography is an integral part of the organic synthesis workflow. For most chemists, they make a compound once and then move on to the next synthesis. Sometimes, the synthesis needs to be sc...
Flash chromatography is nearly ubiquitous within organic and medicinal chemistry labs. Most chemists, when the need arises to purify a reaction mixture, will use a silica column (aka normal-phase) for...
Who knew there were so many different parts to a QuEChERS approach! The nice thing about QuEChERS is even though there are a few different steps to capture your target analytes, they are all Quick, Ea...
If you have ever worked in an environmental laboratory, you might have heard of EPA method 1664B. Method 1664B is an extraction method with analysis by gravimetry that measures oil and grease in waste...
You might be saying to yourself, QuEChERS isn’t an extraction, it’s just QuEChERS! I know when I think extraction, I think of your traditional liquid-liquid or solid-phase extraction where you have a ...
When it comes to chromatographic analysis, it’s no surprise that the analytes of interest are the main focus. After all, those are the compounds one wishes to isolate and quantitate to report to their...
Synthesis workflow is the journey taken by chemists when creating a molecule. This journey can be like taking the interstate with no traffic lights and higher speed limits but usually this trip is mor...
While polar compound purification is frequently performed using a silica column and a DCM/MeOH solvent system, there is a need to reduce its use in chromatography for a number of reasons. First, dichl...
If you are working in an environmental lab and encounter tissue samples and highly contaminated petroleum soil samples that create a lot of noise and interference on your analytical instruments, then ...
Environmental laboratories are often required to demonstrate that their procedures do not introduce background contamination or interferences that would result in false positives or poor analytical pe...
Automated sample prep helps your lab to run more smoothly. Sample prep is often seen as a painful process that is time-consuming, laborious, complex, error-prone, and costly. But efficient sample prep...
For most organic reaction mixture purifications the process is fairly straightforward. Use hexane/ethyl acetate or, for polar compounds, DCM/MeOH. But what do you do if this doesn't work and your comp...
One of the more challenging purifications is that of water-soluble, ionizable compounds. Typically, normal-phase with silica is not used because of the probable non-reversible interactions, especially...
I have recently posted on how solvent choice influences the separation of hard to resolve compounds using normal-phase flash chromatography. As a chemist with an inquiring mind, I thought I would expa...
For chemists needing to purify natural product extracts or synthesis reaction mixtures flash chromatography is typically the tool of choice. In previous posts I have discussed various ways to optimize...
Recently, one of our readers wrote and asked how to determine solvent strength in normal-phase flash chromatography. This is an excellent question because solvent strength is one of several factors im...
In my previous post, I talked about the "Chemistry Behind Normal-phase Flash Chromatography", the most common form of liquid-solid chromatography. In this post, I focus on reversed-phase flash chromat...
For most organic and medicinal chemists flash chromatography is just another step in the synthesis work flow - react, analyze, purify, react, analyze, purify... until the final product is made. The de...
Reversed-phase flash chromatography usage is increasing rapidly. In fact, over the past 10 or so years, reversed-phase flash chromatography use has increased a dramatic 650%! This is amazing growth de...
Flash chromatography competing with prep-HPLC? Why and when would flash outperform or even be equal to prep HPLC? Well, it depends on your purification needs and goals.
Getting the most benefit from your crude sample purification with column chromatography or flash chromatography involves optimizing many variables.
Synthetic chemists continually seek ways to create novel compounds. Along the way they evaluate reagents, solvents, and reaction conditions giving rise to various reaction products and by-products.
In this article I discuss the optimization of solvent ratios to generate ideal Rf (retention factor) values on TLC plates. Then I show how maximizing efficiency of flash chromatography achieves higher...
Underloading your SLE+ samples can result in better partitioning and cleaner samples. Supported liquid extraction (SLE) is a simple clean-up technique similar to liquid-liquid extraction (LLE), but on...
One of the hottest, yet most neglected topics in sample preparation is evaporation. Most chromatographic methods require some form of sample cleanup prior to injection into a HPLC or GC system to prev...
No matter what your sample will be tested for, if you are extracting with liquid-liquid extraction (LLE), solid phase extraction (SPE), accelerated solvent extraction (ASE) or microwave, your sample's...
In the United States, the Environmental Protection Agency (EPA) establishes performance criteria in which laboratories must demonstrate their technical capability to produce results that are accurate ...
Antibodies are indispensable tools that are used in a variety of research applications, diagnostics, and therapeutics. Often, these applications require purified antibodies which means that the antibo...
"How can I take a two hour purification using old-school chromatography, and shorten it?" was the question Dr. Aaron Muth at St. John's University in New York asked himself. "By using the Biotage Isol...
It never fails. A sequence looks relatively straightforward on paper and it's of moderate length so you start synthesizing without too much thought into the protocol. Your synthesis is finished and yo...
Our seasoned peptide chemist Dr. Elizabeth Denton has tried it all when it comes to peptides. In this short video she shows that using DMSO (dimethyl sulfoxide) in a peptide synthesis workflow is perf...
From peptide synthesis to cleavage to dried peptide using the Biotage suite of tools. Ph. D. Elizabeth Denton takes the journey in 3 minutes.
The diversity of amino acid side chain functionalities, coupled with secondary structure, gives peptides and proteins their unique properties and activities. However, when it comes to chemically synth...
What is the main goal of a peptide chemist? Elizabeth Denton, Ph.D., explains how Biotage sees the peptide synthesis workflow and how we focus on shortening the process time for scientists.
In today’s post I’ll answer the above question by comparing the crude purity of peptides synthesized using amino acid stock solutions or freshly dissolved amino acids.
Synthesizing libraries of peptides - potentially hundreds in a single synthesizer setup - has seen a resurgence of late. These synthetic libraries, often prepared on very small synthesis scales, are r...
Breakthrough during reversed phase purification often occurs for only a couple of reasons: 1) the dissolution solvent is too strong and prevents the compound from fully interacting with the stationary...
Biotage® V-10 Touch rapidly dries samples dissolved in both aqueous and organic solvents. It easily evaporates HPLC fractions from purification, high boiling point solvents from synthesis and features...
Getting rid of solvent has long been a bottleneck in organic workflow. With the powerful Biotage® V-10 Touch evaporator, those days are gone. This system can evaporate DMSO and NMP with ease, meaning ...
Have you heard about Biotage® V-10 Touch? If you're struggling with rapidly drying samples dissolved in either aqueous or organic solvents, or evaporating HPLC fractions from purification and high boi...
Flash chromatography can be complex. Solvent choice, column size, stationary phase, loading technique, gradient method, flow rate, and detection parameters are all variables which factor into flash ch...
Flash chromatography is the most commonly used purification tool for organic and medicinal chemists whose reaction scales typically range from milligrams to grams. The column size to be used for the p...
Chemical reactions gone wrong, I’m sure we all have experienced this issue, I know I have. You add your reagents in the proper amounts with a suitable solvent and perform your reaction only to find yo...
Though this is a purification blog I do, from time to time, like to address synthetic chemistry experimentation findings in the desire to assist you with your reactions, as this is the front-end of yo...
Wouldn’t it be nice if your reactions only created your desired product? Of course the answer is yes, but that is not the reality of synthetic chemistry. Because our chemical reactions yield multiple ...
Synthetic organic chemistry is the genesis of new pharmaceutical and commercial chemical products. In short, it is based on the idea that two or more carbon-based compounds can be forced to react usin...
Organic chemistry syntheses often use polar, high boiling point solvents to facilitate high temperature reactions. However, these solvents also can complicate down-stream compound purification, either...
The issue of greener synthesis workflow is becoming more important as chemists, and the institutions that employ them, evaluate various ways to reduce organic solvent use in both synthetic and chromat...
This is a question I asked myself while I have been studying synthesis variables to see what, if any, impact each variable has on reaction product yield and purity. For this post, I evaluated the orde...
For my purification blog I often will synthesize compounds so I can show representative, real-world reaction product purification. In doing so, I decided I would also post on the impact of various syn...
As you know, reaction chemistry involves determining and selecting the right conditions for optimal product yield and purity. There are actually six variables, that I know of, needing consideration in...
This, of course, is always one of the first questions an organic, medicinal, or peptide chemist has when starting the research process for a flash chromatography system. Here at Biotage, we receive th...
While many of the standard amino acids can be purchased pre-loaded onto Wang type resins, there are still cases where coupling the first amino acid onto Wang resin manually is necessary. In my case, a...
For many synthetic chemists the primary purification goal is to isolate as much synthetic product as possible with a minimum of 80% purity. The go-to technique for product isolation is flash purificat...
Purifying your synthetic product efficiently in high yield with minimal impurities is every chemist’s goal. At discovery-scale, flash chromatography is the go-to purification technique as it is relati...
For chemists isolating their synthesized product in maximum yield and purity is a primary goal. Sometimes the crude reaction mixture stays in solution, sometimes it does not. In these cases, is it bet...
For most chemists purifying organic reaction mixtures, normal-phase flash chromatography is the go-to technique. Why not, it is quick, relatively efficient, and can provide relatively high loading cap...
Flash chromatography is a purification technique used by chemists to isolate their targeted compound from by-products and impurities. Because the reaction mixture (or natural product extract) may have...
A good question I get asked frequently to which there is no specific value. When asked this question I answer, “it depends on your sample and how good your separation is”; not a satisfying response, b...
We’ve all done it. Loaded a very small amount of our peptide onto an analytical, maybe semi-prep column, to see where the desired peak elutes, then create a shortened version of that gradient for the ...
Let's be honest. Optimizing a purification protocol for a single peptide is not something that one wants to spend a lot of time thinking about, let alone actually pursuing. There are times though, tha...
Disulfide rich peptides are unique in both their incredibly high cysteine content, but also in the stability imbued by the multiple disulfide bonds. These peptides, stable under extreme conditions tha...
As peptide therapeutics continue to gain interest from the medical community and pharmaceutical companies, concerns regarding the cost of manufacturing also grow. Cost includes the expense of reagents...
I’ve recently worked with several peptide groups that are trying out flash purification with their peptides for the first time. And it never fails, every single interaction includes the question “what...
Big pharmaceutical companies have begun to refocus their efforts towards peptide discovery projects with the hopes of identifying the next big peptide drug. There are often hundreds to thousands of pe...
Covalent stapling strategies that stabilize a particular secondary structure have garnered much attention as interest in peptide therapeutics continues to grow. One such strategy - using olefin-bearin...
In a previous post, I evaluated how flow rate can impact my purification efficiency using flash chromatography. I noticed though, that my peptide eluted significantly later with high mobile phase flow...
Red Glead Discovery (RGD) is a pre-clinical drug discovery CRO offering a broad range of services to Life Science clients. With a focus on small molecules and peptides, their drug discovery platform r...
Every now and then I work with new groups as they embark on a journey incorporating peptides and peptide synthesis into their research. More often than not, no one in the group has experience with pep...
Side reactions. Words that cause a little shiver to run down every peptide chemists’ spine.
Aspartimide rearrangements are a particularly nasty side reaction that can occur during fmoc-based solid phase peptide synthesis. Not only is this a mass-neutral side reaction, chromatographically res...
Almost all the peptides I have synthesized were subsequently purified using a reversed-phase C18 column. Sometimes this worked, but sometimes it didn’t work so well. When my C18 purifications failed, ...
Ion pairing agents are used in a variety of strategies to improve overall purification efficiency.
We've all used mass spectrometry to characterize our synthetic peptides. It's often used to confirm that the peptide was in fact synthesized, then again as part of the purification process to make sur...
Since the development of Fmoc-based solid phase peptide synthesis, a wide variety of cleavage cocktails have emerged. Each cleavage cocktail contains a unique combination of scavengers designed to pre...
Whether it’s the bonded stationary phase, particle size, or even particle pore size, scientists today are offered a plethora of choices when it comes to reversed phase HPLC columns. An often acknowled...
We all use mobile phase modifiers, regardless of purification strategy, for purification of our synthetic peptides. With ionizable side chains, something that affects the pH of the mobile phase is a m...
When purifying crude peptides, we always use a mobile phase modifier. The modifier simplifies a potentially complex purification by driving the desired peptide, and any impurities in the sample, into ...
The isoelectric point (pI) is a physical property of every peptide (and any other compound for that matter) that can be the root cause for many of the issues experienced when handling these compounds....
Analytical laboratories using techniques such as LC-MS/MS or GC-MS are continuously searching for ways to increase throughput, reduce turnaround times and lower costs. Sample prep is often an underest...
Meeting throughput- and efficiency targets in the analytical laboratory working in a Good Laboratory Practices (GLP) environment involves a constant hunt for new ways to improve workflows and sample q...
Do you have a small to medium size analytical lab and are reaching the limit of what you can achieve with manual sample prep? Perhaps you need more robust sample prep with higher efficiency, less hand...
We’ve all heard about Synthetic Opioids and how frequently they’re being abused, creating an Opioid Epidemic. What many of us aren’t hearing about are other synthetic compounds that are out there. Syn...
Novel Psychoactive Substances (NPSs) are drugs that have been made to have similar effects to common drugs of abuse. For example, synthetic opioids like fentanyl were created to make the user think th...
Confused about how to choose the right sample preparation technique for your compound? Don't know if Solid Phase Extraction (SPE) or Supported Liquid Extraction (SLE) would be best for your sample pre...
Understanding the chemical properties of the compounds in your sample matrix, both the ones you want to detect and the ones you want to eliminate, is necessary for successful method development. Is th...
Urine hydrolysis is a part of sample preparation that we do to eliminate glucuronides before urine analysis. So first, what are glucuronides? And why do we want to get rid of them? In this post, I’ll ...
One of the key features of the so called "in-well hydrolysis" is that it can be a time saver for high throughput labs, which makes it look very appealing. In this blog post, I will be discussing some ...
Taking the time to develop a Supported Liquid Extraction (SLE) method using easy steps can save you hours or days of headaches down the road as well as giving you the peace of mind that you’re getting...
Supported Liquid Extraction (SLE) is a sample preparation technique that has been in use for over ten years now, but many analytical chemists don’t know about, or understand the best way to do an SLE ...
For many of us developing an analytical assay requires numerous experiments in addition to lots of data review, and yet despite the feeling of confidence in our success, how reliable is our assay real...
How the acid dissociation constant (pKa) affects sample preparation method development? Knowing and understanding the pKa of your compounds tells you if the compound can be ionized, and under what con...
Mixed mode Solid Phase Extraction (SPE) phases have become very popular for sample clean-up prior to analysis using mass spectrometry. Having the capability to retain compounds by two modes of interac...
What is a weak ion exchange SPE phase? What is their charge state and how they behave in function of pH conditions? When to choose them? This post will describe Biotage mixed mode weak ion exchange SP...
When it comes to sample cleanup the question occasionally comes up asking what technique is best for my application: Solid Phase Extraction (SPE) or Supported Liquid Extraction (SLE)? Well, what’s rig...
There is often confusion as to how to choose the proper SPE ion exchange media. How do you determine if you should be looking at anion or cation, weak or strong? In this post, I will give some simple ...
When running through the exhaustive process of method development, most of us put the majority of our focus on validation and how to complete our crazy validation checklists. Throughout this process, ...
LC/MS/MS seems to be the gold standard in sample analysis nowadays. However, some labs are still analyzing samples using GC/MS. The majority of published peer-reviewed articles are for LC/MS/MS, so th...
In this blog post, we will discuss how to determine the optimal sample volume for a sorbent bed mass. We have developed an adequate solid phase extraction method for our laboratory. However, we're sta...
Solid-phase extractions (SPE) can be a long and sometimes complicated process. So, we want to make sure that everything works the first time we extract. In this blog post, I will be discussing some of...
If you are frustrated with low recoveries caused by protein binding during Supported Liquid Extraction (SLE) and Solid Phase Extraction (SPE), this blog post will give you a few tips. Proper sample pr...
It happens to all of us. We're getting a new method developed and validated and then it comes time to run our negative urines. And everything comes up as positive! There are peaks for our analytes of ...
Have you ever encountered problems loading your samples onto an SPE or SLE plate? Aside from sample viscosity or cartridge blockages, a good troubleshooting step to start with is ensuring that you are...
Most clinical and forensic labs have a used a traditional approach for drug testing called screen with reflex to confirmation. This involves analyzing samples using an immunoassay technique that ident...
Let's face it, the whole solid phase extraction method development process can be time consuming and expensive. So Dilute-and-Shoot methods end up being the choice in some laboratories. The problem is...
Synthetic cannabinoids are some of the most widely abused drugs in the world. They are structurally similar and have similar effects to marijuana but are frequently referred to as “legal highs”. Chemi...
The sole purpose for method development is to construct a robust and analytically sound method that will not just pass the barriers of validation, but provide physicians and patients with sound and re...
When trying to develop a new method for the detection of a drug panel, you need to refer to reliable sources to learn all you need to know regarding your analytes. For this post, we’ll go in detail th...
Before we get into our extractions, we need to set up our LC/MS to detect our analytes of interest. The LC will provide the chromatography - or separation of our analytes - and the MS will support det...
Evaporative crosstalk is contamination that occurs during evaporation of the elution solvent after SLE or SPE extraction. Volatile analytes evaporate, then redistribute in adjacent wells in a 96-well ...
You've just decided to develop a solid phase extraction (SPE) method for a new assay in your lab. However, there are so many decisions to be made! Which company to choose? Which product to use? Polyme...
We’ve all been there. We prepare a batch of samples to analyze, prime our systems, warm up the detector, and within 2-3 injections we receive an error message stating that an integral component has fa...
Conversations are routinely held regarding handling hydrophobic peptides, but hydrophilic peptides offer their own challenges when it comes to purification.
Every now and again I hear the question “which solvent do you recommend for my solid phase peptide synthesis?” Historically, dichloromethane (DCM) was used as a solvent for solid phase synthesis as th...
Sometimes the most interesting peptides are also the absolute worst to work with. Whether it's synthetic difficulty, or solubility issues, or purification difficulty, or worst of them - all of the abo...
This is a question that I am often asked by very smart people that just haven’t had time to learn the process. An optimized sample preparation method is critical for an accurate, specific, robust clin...
Most clinical chemists have developed a blood, serum or plasma assay using a protein crash because it is inexpensive and generally removes proteins that interfere with detection or the analysis in som...
When would I choose SLE? When would I choose SPE? We all have faced those questions. Let's have a look at the two sample preparation techniques.
Highly sensitive techniques such as LC-MS/MS are enabling analytical laboratories to generate more data on more analytes in more samples, in less time, at a lower cost, and using smaller sample volume...
Solid phase extraction (SPE) is frequently used for sample clean up, trace enrichment (pre-concentration of the sample), or a combination of both prior to analysis. But can solid phase extraction be a...
A prime objective of bioanalytical sample preparation is to achieve high analyte recovery in low elution volumes, with rapid delivery of clean extracts that support robust high sensitivity analysis to...
Urine samples are composed of many interferents which can cause ion-suppression or ion-enhancement when analyzing by mass spec. Build up of these matrix components over multiple sample injections can ...
What's the process behind tuning our analytes to the mass spectrometer’s optics? And why is that so important?
Let’s take a look at one of the more irritating issues in LC/MS method development: signal loss. I’m not talking about signal attenuation, which can be much more convoluted to diagnose; but rather a c...
A new method has been developed for the combined analysis of Vitamin A, Vitamin D, Vitamin E and Vitamin K from serum using LC-MS/MS. The method uses supported liquid extraction (SLE) with a novel sam...
Microelution SPE is a great alternative to conventional SPE methods, enabling the use of lower wash and elution volumes, while maintaining sufficient load volumes, providing concentrated samples, perf...
Many Labs today are faced with the challenge of having to do more with existing personnel and space. When looking at developing or modifying a LC/MS or GC/MS assay, one of the most important steps is ...
So, you’ve decided that you need to develop some new methods and one of the biggest challenges is the cost of developing and validating new methods. So, what to do to speed up the process?
Developing a new sample prep method should be systematic to ensure ruggedness and can be done quickly with the right tools. The days of using a vacuum manifold are gone, along with the variability and...
Correct pretreatment of samples prior to supported liquid extraction (SLE) produces better partitioning and cleaner extracts. Supported liquid extraction (SLE) is a simple clean-up technique similar t...
Choosing the SLE correct elution solvent based on analyte properties produces the cleanest extracts with the highest recoveries.
This concept seems simple today, but traditional nitrogen evaporators haven’t been overhauled for many years. Even in our lab we were not able to store evaporation methods…until now!
It is easier to understand something when you know what the actual word means. A thermistor is a portmanteau (yes, sometimes I do pay attention to linguistics) of the words thermal and resistor. This ...
Phenolic compounds can be some of the most challenging compounds to extract from the compound lists in EPA Method 8270 and EPA Method 625.1. The recovery of these compounds suffer tremendously compare...