Sodium

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Sodium and potassium ions can be separated on a mixed-mode Newcrom AH column with a simple isocratic mobile phase of water, acetonitrile (ACN) and methanesulfonic acid.  It can be detected using a conductivity detector.

HPLC Method for Analysis of Tetramethylammonium, Sodium, Potassium on Newcrom AH by SIELC Technologies

Tetramethylammonium chloride is a quaternary ammonium salt used widely as a reagent in industrial applications.  It can be separated from sodium and potassium chlorides on a mixed-mode Newcrom AH column with a simple isocratic MS-compatible mobile phase of water, acetonitrile (ACN) and ammonium formate (AmFm) buffer.

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The ionic forms of Chlorate, Perchlorate, and Phosphonates are useful in many industries including medicine, paper and use in explosives. Due to their lack of UV activity, an ELSD was used to detect both the anions and cations of all three sodium salts. The ions were retained on both Primesep D and Obelisc R columns. Primesep D is a reverse phase column with embedded basic ion-pairing groups. Obelisc R is also a reverse phase column, but can be additionally tuned due to embedded ionic groups and a hydrophobic chain.

Paraquat, diquat and glyphosate are three of most widely used herbicides in the world. Paraquat and diquat are very polar and very basic quaternary amines. Glyphosate is an aminophosphonic analog of glycine. It is very polar and acidic at most of the pH of the mobile phase. Since glyphosate and the quats have opposite charges no ion-pairing method can be developed for the mixture of basic and acidic herbicides. All three herbicides were separated on the Obelisc R tri-modal column. Paraquat and diquat are retained by a cation-exchange mechanism, and glyphosate is retained by weak reversed-phase and strong anion-exchange mechanisms. This method can be used for analysis of common herbicides in fruits, vegetables, ground water, drinking water and other matrices. Method is LC/MS compatible and can be used to determine trace levels of herbicides.

The citric acid cycle (tricarboxylic acid cycle, Krebs cycle) is a key process in the metabolic pathway by which all aerobic organisms generate energy. Compounds generated during TCA are hydrophilic, acidic compounds. Some of the hydrophilic acids are very strong while others are relatively weaker. All compounds have very low hydrophobicity and do not retain by the reversed-phase mechanism on the C18 or C8 HPLC columns. Citric acid and related products were separated in reversed-phase, anion-exchange mode on the Primesep D mixed-mode column. All hydrophilic, acidic compounds are well separated and demonstrate good shape. This robust method can be used for analysis of components of the TCA cycle and other highly hydrophilic compounds. This method is fully compatible with LC/MS and prep chromatography.

Sulfosuccinic acid and the corresponding dioctyl ester were separated on the Primesep B4 short carbon-chain anion-exchange column. Short carbon chain stationary phase allows to elute hydrophobic and acidic diester in reasonable time. No elution was observed on the mixed-mode columns with longer carbon chain analogs due to very strong hydrophobic and anion-exchange interaction.

Application Notes: Dioctyl sodium sulfosuccinate is a common component of consumer products and medications. It is also used as emulsifier, wetting, and dispersing agent.  It is a highly acidic, and hydrophobic compound. It serves as a starting material for dioctyl sodium sulfonate. Both compounds were retained and separated on Primesep B4 mixed-mode reversed-phase anion-exchange column. The primesep B4 column has C4 carbon chain and it is much less hydrophobic than Primesep D or Primesep B2 column. The low hydrophobicity of the stationary phase is strong enough to provide reversed-phase retention for dioctyl sulfosuccinic acid. This method can be used for quantification of these two compounds in reaction mixtures and formulation. The method is LC/MS and ELSD/CAD compatible.

 
Application Columns: Primesep B4

 
Application compounds: Sodium, Dioctyl Sulfosuccinic Acid, Sulfosuccinic Acid

Detection technique: LC/MS, ELSD/CAD

Primesep D mixed-mode column separates organic acids such as succinic acid, malic acid, MPS and butanesulfonate by a mixture of anion exchange and reversed phase mechanisms. Retention times can be changed by adjusting the percentage of acetonitrile in the mobile phase. This can not be done by traditional ion-exchange and ion-exclusion chromatography. The HPLC separation uses a mobile phase of water, acetonitrile (MeCN, ACN) and ammonium formate as a buffer, making the method MS-compatible. Can also use UV detection at 250 nm.

Neutral sugar, monovalent and divalent cations were separated in HILIC/cation-exchange mode on a Primesep N mixed-mode column. Mobile phase is compatible with LC/MS and method can be used for analysis polar molecules in HILIC, cation-exchange or anion-exclusion modes.

Hydrophilic and hydrophobic quaternary amines, along with sodium ion, were separated by mixed-mode chromatography on a Primesep 200 column. Mechanism of retention for sodium and tetramethylammonium ions is cation exchange, while the tetrabutylammonium ion is retained by combination of reversed-phase and cation-exchange mechanisms. All three compounds are not UV-active and monitoring is done by ELSD/CAD.

Alkyl sulphonic acids are used as surfactant additives in many products. Homologs of linear alkyl sulfonates are separated on a Primesep 500 mixed-mode cation exchange column in reversed-phase anion-exclusion mode. This generic method can be used for determination of alkyl sulfonates in detergents, soaps, etc.

Halide ions are usually analyzed by ion-chromatography with a conductivity detector. Mixed-mode chromatography in combination with ELSD is offering a valuable alternative to ion-chromatography with conductivity detection. Chloride, bromide and iodide were separated on a Primesep SB mixed-mode anion-exchange column. Mobile phase is compatible with ELSD and LC/MS.

Sugar phosphates occur in biological systems. Sugar phosphates are parts of two metabolic pathways: glycolisis and pentose phosphate pathways. One of the purposes of sugar phosphates is to store and transfer energy in cells. Because of the presence of sugar fragment and phosphate moiety these molecules are very polar in nature. Mixed-mode chromatography was applied for separation of glucose and fructose phosphates and diphosphates. Compounds are separated based on anion-exchange properties with diphosphates retaining longer than mono phosphates. Monitoring is done by ELSD.

Separation type: Liquid Chromatography Mixed-mode

Inorganic cations and ammonia are usually analyzed by ion-exchange chromatography with a conductivity detector. Mixed-mode chromatography achieves the same goal with an ELSD detector. In addition to retaining ions, mixed-mode column can retain hydrophobic molecules also, making it possible to analyze a wide variety of ionic and non-ionic compounds in one run. In this method sodium, potassium, and lithium ions were separated along with ammonium ions on a Primesep 100 column. Detection technique is ELSD.

Inorganic cations and anions are usually analyzed by two different methods – cation-exchange and anion-exchange. This requires development and validation of two methods. Both ions can be analyzed on mixed-mode HILIC column with ELSD detection. Both ions are retained by combination of HILIC and ion-exchange mechanism.

Sulfate and phosphate are separated on Primesep B2 and Primesep D column by anion-exchange mechanism. Because both sulfate and phosphate ions are not UV-active, ELSD is used to monitor separation of both anions. Method can be used to quantitate phosphate and sulfate in various pharmaceutical and chemical formulation, products and solution, drinking and ground water. Retention time is adjusted by increase or decrease of buffer concentrations. Two anions can be retained and separated on a very short column due to strong ion-exchange interaction. Method shows good reproducibility and versatility.

Citrulline and Arginine are α-amino acids that differ only in one functional group. They can be separated on a reverse-phase Primesep 200 HPLC column by hydrophobic and cation-exchange mechanisms in a mobile phase of water and acetonitrile (MeCN, ACN) with a gradient buffer of formic acid. Evaporative Light Scattering Detector (ELSD) used.

Surfactants are molecules that contain both hydrophilic and hydrophobic groups, usually in the form of a hydrophilic head and a hydrophobic tail. Surfactants are used in detergents where they can form micelles around hydrophobic dirt molecules and wash them away. Triton X-100 is a surfactant with a hydrophilic polyethylene oxide chain that can be separated on a Primesep D reverse-phase HPLC column based on the number of oxide units in the chain. The mobile phase is water, acetonitrile (MeCN, ACN) and sulfuric acid as buffer. UV detection at 210nm.

Primesep C separates a mixture of inorganic cations, potassium, sodium, and lithium, by a combination of cation exchange and complex formation. The peak order is reversed on the Primesep C column compared to the order normally obtained on columns that rely on cation exchange alone. The mobile phase mixture of water, acetonitrile (MeCN, ACN) and ammonium acetate is compatible with UV and evaporative light scattering detection (ELSD).

Primesep 100 and Primesep B columns connected in series allow the quantitation of sodium chloride and potassium bromide ions in one injection. The Primesep B column retains the chloride and bromide anions by anion exchange, and the Primesep 100 retains the sodium and potassium cations by cation exchange. The retention can be adjusted by changing the water/acetonitrile ratio in the mobile phase. The separation uses a mobile phase mixture of water, acetonitrile (MeCN, ACN) and ammonium acetate with evaporative light scattering detection (ELSD).

Primesep 100 and Primesep B columns connected in series allow the quantitation of sodium chloride and potassium bromide ions in one injection. The Primesep B column retains the chloride and bromide anions by anion exchange, and the Primesep 100 retains the sodium and potassium captions by cation exchange. The separation uses a mobile phase mixture of water, acetonitrile (MeCN, ACN) and trifluoroacetic acid (TFA) with evaporative light scattering detection (ELSD).

Primesep C separates a mixture of inorganic cations, potassium, sodium, and lithium, by a combination of cation exchange and complex formation. The peak order is reversed on the Primesep C column compared to the order normally obtained on columns that rely on cation exchange alone. In addition, the elution order can be rearranged by simply changing the organic modifier in the mobile phase from acetonitrile to methanol. The mobile phase mixture of water, acetonitrile (MeCN, ACN) or methanol (MeOH) and ammonium acetate is compatible with UV and evaporative light scattering detection (ELSD).

Primesep 100 allows the quantitation of sodium and zinc cations in a drug product sample. The cations are retained by cation exchange and the drug product is retained by hydrophobic, reversed-phase mechanisms. The separation uses a mobile phase mixture of water, acetonitrile (MeCN, ACN) and trifluoroacetic acid (TFA) with evaporative light scattering detection (ELSD) and UV detection.

Primesep 100 separates guanidine from its sodium counterion on a short 50 mm column by cation exchange. Guanidine is found in urine as a product of protein metabolism and is also used in the manufacture of plastics and explosives. Guanidine is detected by UV detection at 200 nm, but UV cannot detect the sodium ion. If an evaporative light scattering detector (ELSD) is used, both components can be detected. The separation method uses a mobile phase mixture of water, acetonitrile (MeCN, ACN) and trifluoroacetic acid (TFA).

Primesep 100 separates the monovalent cations, lithium, potassium, and sodium, and the divalent cations, zinc, manganese, and calcium. The cations are resolved by cation exchange. The mobile phase mixture of water, acetonitrile (MeCN, ACN) and trifluoroacetic acid (TFA) is evaporative light scattering detection (ELSD) compatible.

High nitrate concentrations in water and soil can be toxic to humans, fish and domestic animals.  Chloride can be used for analysis of water contamination. Primesep D column can be used to separate and quantify both ions.  The baseline separation between chloride and nitrate can be increased by decreasing the ammonium formate concentration in the mobile phase.  Evaporative Light Scattering Detection (ELSD) used.