Application Notes: LC

Ultrahigh throughput is shown for ultrafast gradients with over 60 % reduction of total analysis time using alternating column regeneration. This was accomplished with parallel injection by the second needle installed in the Agilent 1290 Infinity II Multisampler, which has a dual-needle option for the analysis of food preservatives.

Ultrahigh throughput is shown for ultrafast gradients with over 60 % reduction of total analysis time using alternating column regeneration. This was accomplished with parallel injection by the second needle installed in the Agilent 1290 Infinity II Multisampler, which has a dual-needle option for the analysis of food preservatives.

The Agilent 1290 Infinity II High Dynamic Range Diode Array Detection Impurity Analyzer Solution combines the signals from two diode array detectors with different path length Max-Light cartridge cells to increase the linear dynamic UV-range. This solution can be used to detect and quantify main and trace compounds in a single run without exceeding the linear UV-range.

"This Application Note shows the analysis of 20 explosives with the Agilent 1290 Infinity II Variable Wavelength Detector (VWD) in dual-wavelength mode using 254 and 214 nm."

This Application Note describes the use of the Agilent 1290 Infinity II LC for the automated operation of seven different applications using different methods in food analysis. The exchange of columns is controlled by the method used. All columns are located in a single Agilent 1290 Infinity II Multicolumn Thermostat. Accordingly, the Agilent 1290 Infinity II Flexible Pump is attached to two external solvent-selection valves for automated solvent switching.

Evaporative light scattering (ELS) is a unique and highly sensitive technique for detection of semivolatile and nonvolatile solutes in a liquid stream. As a consequence of the physics of light scattering, conventional ELS detectors have a relatively small dynamic range. In contrast, the Agilent 1290 Infinity II Evaporative Light Scattering Detector has a 10-times higher dynamic range compared to conventional ELS detectors.

This Application Note describes the use of the Agilent 1290 Infinity II LC for the automated operation of seven different applications using different methods in food analysis. The exchange of columns is controlled by the method used. All columns are located in a single Agilent 1290 Infinity II Multicolumn Thermostat. Accordingly, the Agilent 1290 Infinity II Flexible Pump is attached to two external solvent-selection valves for automated solvent switching.

Evaporative light scattering (ELS) is a unique and highly sensitive technique for detection of semivolatile and nonvolatile solutes in a liquid stream. As a consequence of the physics of light scattering, conventional ELS detectors have a relatively small dynamic range. In contrast, the Agilent 1290 Infinity II Evaporative Light Scattering Detector has a 10-times higher dynamic range compared to conventional ELS detectors.

"This Application Note shows the analysis of 20 explosives with the Agilent 1290 Infinity II Variable Wavelength Detector (VWD) in dual-wavelength mode using 254 and 214 nm."

Shimadzu Europa GmbH

UCT, LLC

Agilent Technologies

Agilent Technologies, Inc

With the 1290 Infinity HDR DAD the determination of low and high dose drugs present in a fixed dose combination drug was possible in one run, due to the increased linear dynamic range by >30x.

The term ionic liquid refers to organic salts with relatively low melting points (below 100 °C) that usually consist of an organic cation or anion and a counterion, in either organic or inorganic form. Ionic liquids exhibit unique characteristics such as extremely low vapour pressure, excellent thermal stability, electrical conductivity, a high degree of polarity and miscibility with various types of solvents. Ionic liquids have been used as catalysts and solvents in organic chemistry and electrochemistry and as mobile phase modifiers or functionalized stationary phases in separation science.1–3

In the pharmaceutical industry the increased efficiency brought about by new fast chromatography methods needs to be matched by commensurate mass spec capabilities. maXis UHR-TOF is the instrument of choice to keep up with fastest chromatography.

Catecholamines are important markers for the diagnosis and management of tumour diseases of the sympathoadrenal system. The major catecholamines are dopamine, norepinephrine and epinephrine. Urine tests have shown to be applicable to measure the level of catecholamines in the human body. Various separation methods have been used for the clean-up of catecholamines in biological fluids: solvent extraction, adsorption on alumina, ion-exchange and solid-phase extraction of a diphenylboronic acid-catecholamine complex. From the point of simplicity, reproducibility and automation the last method is the most suitable and can be realized by on-line SPE–LC. Diphenylborate forms a negatively charged complex with the diol groups of catecholamines. These complexes which are strongly retained on a polystyrene-divinylbenzene cartridge in alkaline medium (pH 8.5) can be eluted in a second step from the SPE unit directly onto the HPLC column. The separation of catecholamines is performed in isocratic mode by..

As UPLC users convert or replace their existing HPLC systems with UPLC systems there is a transition period where a method must be run on both platforms. Thus, having the same particle substrate and bonded phases available in HPLC and UPLC particle sizes can significantly ease the burden of method development and transfer from one platform to another. In addition to the ethylene bridged hybrid (BEH) particle, three new high strength silica (HSS) stationary phases for HPLC applications are introduced. Scalability between both column diameter and particle size is demonstrated on both UPLC and HPLC instrumentation.

Increase throughput of the HPLC method for triazine herbicides by employing ultra high-speed liquid chromatography at elevated temperature on a heat stable Thermo Scientific Hypercarb column.

All plant foods are complex mixtures of chemicals including both nutrients and biologically active non-nutrients, referred to as phytochemicals. Soy is known for having high concentrations of several physiologically-active phytochemicals, including isoflavones, phytate (inositol hexaphosphate), saponins, phytosterols and protease inhibitors. The isoflavones are what makes soy unique.

Flavanones are a type of flavonoids occurring widely in plants, either in the aglycone backbone form itself or as glycosides. Flavonones exist in unique forms depending on the type of fruit and can be used to indicate the type of fruit that is being analysed. The following application introduces examples of high-speed analysis of flavanones in citrus juice using the Shimadzu ultra fast LC system, prominence UFLC, and the photodiode array detector SPD-M20A, focusing on narirutin, naringin, neohesperidin and hesperitin.

The FDA has no objection to Rebaudioside A having a generally recognized as safe (GRAS) status as a sweetener for food and drink.1 Stevia sweeteners may contain other steviol glycosides as well, mainly Stevioside, Rebaudioside C and Dulcoside A. Because the FDA GRAS confirmation is only for the use of Rebaudioside A at 95% purity or above in food and beverages, stevia extracts must be highly purified and characterized prior to use.

Zhe Yin, Kenneth J. Fountain, Erin E. Chambers and Diane M. Diehl, Waters Corporation, Milford, Massachusetts, USA.

Based on the QuEChERS AOAC Official Method 2007.01, 16 pesticides were used for evaluating the performance of the Agilent's AOAC buffered extraction and SampliQ QuEChERS dispersive SPE kits for general fruits and vegetables.

Tobacco specific nitrosamines (TSNA) are a group of carcinogens found only in tobacco products and are formed from nicotine and related alkaloids during the production and processing of tobacco and tobacco products.

Polynuclear aromatic hydrocarbons (PAHs) are carcinogenic condensed ring aromatic compounds widely found as trace pollutants in waters, wastes, air particulates, soil and foods. PAHs can be routinely monitored using HPLC with a combination of UV and fluorescence detection as prescribed in EPA methods 550.1, 610 and 8310.

Polyaromatic hydrocarbons (PAH) are particularly relevant in the analysis of environmental pollution because of their ubiquity, toxicity and persistence. Consequently, the PAHs have become the most intensively studied pollutants in environmental analysis.

Salt formation is a critical aspect in drug development and HPLC is an important tool for determination of pharmaceutical counterions.

Since melamine and its metabolites are extremely polar compounds, they serve as very good candidates for HILIC chromatography. Simultaneous and fast determination and confirmation of melamine and cyanuric acid along with two other compounds using a novel amino bonded phase in HILIC mode coupled with a complete solutions approach is presented.

An Agilent ZORBAX Rapid Resolution HT Eclipse Plus Phenyl-Hexyl column resolved many compounds from Stevia rebaudiana Bertoni plant extracts using an isocratic reversed phase method with UV and MS detection instead of a typical approach employing an amino column with a refractive index or other special detector. The Eclipse Plus Phenyl-Hexyl method's advantages include high peak capacity, isocratic mobile phase, low acetonitrile consumption, and MS compatibility.