The determination of the chemical composition distribution of acrylic resins is not straightforward. Pyrolysis–gas chromatography (py-GC) analyses of acrylic resins can yield problems in the recovery of the hydroxyl and acid functional fragments that form. To overcome these problems pyrolysis–liquid chromatography (py-LC) can be performed. This article describes how the validation and quantification of hydroxyl acrylate-, hydroxyl methacrylate-, hydroxyl propylacrylate-, and hydroxyl propylmethacrylate resins by py-LC is performed. Furthermore, off-line size-exclusion chromatography (SEC) coupled to py-LC is performed to determine the chemical composition distribution over the molecular weight distribution of a core–shell waterborne acrylic resin.
The determination of the chemical composition distribution of acrylic resins is not straightforward. Pyrolysis–gas chromatography (py-GC) analyses of acrylic resins can yield problems in the recovery of the hydroxyl and acid functional fragments that form. To overcome these problems pyrolysis–liquid chromatography (py-LC) can be performed. This article describes how the validation and quantification of hydroxyl acrylate-, hydroxyl methacrylate-, hydroxyl propylacrylate-, and hydroxyl propylmethacrylate resins by py-LC is performed. Furthermore, off-line size-exclusion chromatography (SEC) coupled to py-LC is performed to determine the chemical composition distribution over the molecular weight distribution of a core–shell waterborne acrylic resin.
Food quality differences are dependent on botanical and geographical origins of primary food ingredients as well as storage and handling. Quality assessment for food materials, including cocoa and olive oil, is demonstrated by applying two-dimensional gas chromatography (GC×GC) combined with time-of-flight mass spectrometry (TOF-MS) and pattern recognition.
How to speed up sample prep time and equivalent acccuracy and precision.
A one-day symposium, organized by The Chromatographic Society, discussing practical advances in automation and data processing in modern science laboratories was held at Syngenta Research Laboratories in Bracknell, Berkshire, UK, on 25 October 2016.
A new method to deal with the interaction of transition metals with analytes has been developed and is described.
The Reid International Bioanalytical Forum is a conference geared towards bioanalytical scientists. It has a unique philosophy where challenging data is often presented to an audience who are encouraged to engage. This article describes how the meeting series was initiated and developed over the past 40 years and how this philosophy has been embedded into the meeting.
The Reid International Bioanalytical Forum is a conference geared towards bioanalytical scientists. It has a unique philosophy where challenging data is often presented to an audience who are encouraged to engage. This article describes how the meeting series was initiated and developed over the past 40 years and how this philosophy has been embedded into the meeting.
Practical examples of how to correct for matrix effects in food testing to obtain reliable quantitative data using LC–MS and GC–MS
This article describes the development of a HPLC method for the assay of green fluorescent protein (GFPuv) in-process samples from our model therapeutic protein production process. Specificity of the method is evaluated by demonstrating a suitable HPLC method to separate and detect closely related protein degradation species.
This article describes the development of a HPLC method for the assay of green fluorescent protein (GFPuv) in-process samples from our model therapeutic protein production process. Specificity of the method is evaluated by demonstrating a suitable HPLC method to separate and detect closely related protein degradation species.
A snapshot of key trends and developments in the GC/GC–MS sector according to selected panelists from companies exhibiting at Analytica 2018.
The German Beer Purity Law of 1516 makes beer one of the best analyzed food products with the highest standards regarding quality, freshness, appearance, and flavor. According to this law, beer is allowed to contain hops, malt, yeast, and water as ingredients. Of course, beer also contains major B vitamins, bitter substances, and minerals and trace elements (such as Ca, Na, Mg, and Zn) that are important for human nutrition. However, undesirable substances such as pesticides and heavy metals (for instance Cd, Pb, Hg, Sb, and As) can be found as well, mostly as contaminants in brewing water and grains. In particular, the herbicide glyphosate has to be monitored carefully since it is discussed as a possible carcinogenic. The chromatography of glyphosate is challenging because of its high polarity. A well-established method including a derivatization step with 9-fluorenylmethyl chloroformate (FMOC) followed by LC–MS analysis is time-consuming and also susceptible to errors. A sample pretreatment without derivatization is desirable because it is faster and cheaper. A triple quadrupole mass spectrometer optimizes the analytical procedure and establishes a routine method for the analysis of glyphosate in beer. For the determination of low element concentrations, such as As, Se, Pb, Cd, and Zn, inductively coupled plasma-mass spectrometry (ICP-MS) is applied.
A look at some of the opportunities ChromSoc currently offers.
Carbon tetrachloride (CCl4) is a potent greenhouse gas in the troposphere, while in the stratosphere it contributes to ozone destruction. Global atmospheric models treat anthropogenic industrial processes as the sole source of atmospheric CCl4. However, some evidence suggests that biogenic sources may also contribute. This article describes grab-sampling with analysis by thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS) to assess levels of CCl4 in a Central Amazonian rainforest. We find that ambient air mixing ratios within and above the forest, while agreeing with current equatorial estimates (120 ppt), show diurnal and canopy-height variations that suggest a biogenic source of CCl4, and therefore may be important for closing the gaps in the global atmospheric CCl4 budget.
Carbon tetrachloride (CCl4) is a potent greenhouse gas in the troposphere, while in the stratosphere it contributes to ozone destruction. Global atmospheric models treat anthropogenic industrial processes as the sole source of atmospheric CCl4. However, some evidence suggests that biogenic sources may also contribute. This article describes grab-sampling with analysis by thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS) to assess levels of CCl4 in a Central Amazonian rainforest. We find that ambient air mixing ratios within and above the forest, while agreeing with current equatorial estimates (120 ppt), show diurnal and canopy-height variations that suggest a biogenic source of CCl4, and therefore may be important for closing the gaps in the global atmospheric CCl4 budget.
Perchlorate salts are relatively stable, soluble in water, and migrate into groundwater sources causing possible challenges for drinking water suppliers as dissolved perchlorate has been identified to impair normal thyroid function. The development of a sensitive analytical method for perchlorate determination is therefore important to protect public health. This article addresses the validation of ion chromatography with suppressed conductivity detection (IC–CD), applying isocratic elution to analyze perchlorate.
Perchlorate salts are relatively stable, soluble in water, and migrate into groundwater sources causing possible challenges for drinking water suppliers as dissolved perchlorate has been identified to impair normal thyroid function. The development of a sensitive analytical method for perchlorate determination is therefore important to protect public health. This article addresses the validation of ion chromatography with suppressed conductivity detection (IC–CD), applying isocratic elution to analyze perchlorate.
Perchlorate salts are relatively stable, soluble in water, and migrate into groundwater sources causing possible challenges for drinking water suppliers as dissolved perchlorate has been identified to impair normal thyroid function. The development of a sensitive analytical method for perchlorate determination is therefore important to protect public health. This article addresses the validation of ion chromatography with suppressed conductivity detection (IC–CD), applying isocratic elution to analyze perchlorate.
Perchlorate salts are relatively stable, soluble in water, and migrate into groundwater sources causing possible challenges for drinking water suppliers as dissolved perchlorate has been identified to impair normal thyroid function. The development of a sensitive analytical method for perchlorate determination is therefore important to protect public health. This article addresses the validation of ion chromatography with suppressed conductivity detection (IC–CD), applying isocratic elution to analyze perchlorate.