Invented by Darryl W. Brousmiche, Jacob N. Fairchild, Jason F. Hill, Giorgis Isaac, Michael F. Morris, Kevin D. Wyndham, Waters Technologies Corp
The Waters Technologies Corp invention works as followsThe present disclosure is a method for separating an unsaturated compound or compounds of interest from a mixture. Separation of the compound occurs using a column containing a stationary phase for chromatography in various modes containing both a first and second substituent. The first substituent reduces the variation in compound retention over time when chromatographic conditions are used. The second substitute retains the compound chromatographically by incorporating aromatic, polyaromatic or heterocyclic aromatic hydrocarbons, with each group optionally being replaced with an aliphatic. The present disclosure may include, in some examples, a system of chromatography having a chromatographic pillar with a stationary phase and a chromatographic substratum containing silica or metal oxide.
Background for Chromatographic Materials for the Separation of Unsaturated Molecules
Chromatography” is a collective term used to describe a collection of laboratory techniques that are used for the separation and purification of mixtures. The mixture is dispersed in a mobile state, which then carries it to a stationary state. Separation occurs because the constituents of a mixture move at different speeds. Separation is caused by differential partitioning of the stationary and mobile phases. The difference in the partition coefficient of a compound can result in different retentions on the stationary phase. This changes the separation. Chromatography can be used to separate compounds with structural similarities, like regioisomers and chiral diastereomers. SFC is one technique that has been proven to be particularly effective in separating vitamins, natural products, and chemical materials with structurally similar compositions. Chromatographic techniques, however, are often not sufficient to separate structurally related compounds. “For example, it is difficult to resolve/separate critical pairs of related vitamin (e.g. D2 and K1, K1 and K2).
Packing materials used in liquid or fluid chromatography are generally divided into two categories: organic materials (e.g. polydivinylbenzene), and inorganic (e.g. silica). Organic materials can be chemically stable with both strongly acidic and strongly alkaline mobile phases. This allows for flexibility in choosing the mobile phase pH and composition. Organic chromatographic material can cause columns to be inefficient, especially when used with analytes of low molecular weight. “Many organic chromatographic material not only lack mechanical strength as typical chromatographic silicon, but also shrink and swell if the composition of mobile phase is altered.
Silica has been widely used in High Performance Liquid Chromatography, Ultra High Performance Liquid Chromatography and Supercritical Fluid Chromatography.” In some applications, silica is surface-derivatized using organic functional groups such as octadecyl(C18), octyl(C8), amino, or cyano. These packing materials are excellent for HPLC stationary phases. They can produce columns with high efficiency, and without any signs of swelling or shrinking.
Hybrid materials may be able to solve certain chromatographic issues that silica-based packing materials have. “Hybrid materials provide improved stability at high and low pH, mechanical stability, peak form when used at pH 7, efficiency and retentivity as well as desirable chromatographic selection.
In other applications, silica and conventional hybrid materials can pose problems. Poor peak shape can be a problem for bases at low pH. This can have a negative impact on loadability and peak capacities. A change in the retention time of acidic and basic analytes (also called drift?) is another problem. After a column has been exposed to repeated pH changes (e.g. switching repeatedly from pH 10 down to pH 3).
Another issue is retention drift or changes, for example, in chromatography mode with less water (e.g. less than 5%). Under standard SFC conditions, for example, both silica or organic-inorganic (e.g. BEH Technology) hybrids, there is a tendency to see a change in retention. Waters Technologies Corporation in Milford Mass., offers a wide range of materials. Based chromatographic phase, both bonded and non-bonded. “Staying phases of other SFC can also show similar drifts or changes in retention.
The present disclosure, in various aspects and embodiments provides chromatographic material for normal phase chromatography (HPLC), high-pressure liquid-chromatography (HPLC), solvated-gas chromatography (SFC), sub-critical-fluid-chromatography (SFC), carbon dioxide-based chromatography (CDC), hydrophilic-interaction liquid-chromatography and hydrophobic-interaction liquid-chromatography for separation of unsaturated molecule, which mitigates or avoids retention drift or changes
The present disclosure has a number of additional advantages including, but not limited, to the ability to select/design selectiveness through the selection/designing of chemical modifications.
In one embodiment, the present disclosure relates to a method of separating a compound of interest from a mixture, the method comprising providing a mixture containing the compound of interest, introducing a portion of the mixture to a chromatographic system having a chromatographic column, and eluting the separated compound of interest from the column, wherein the column has a stationary phase having the following structure (i):\n[X](W)a(Q)b(T)c?? (i)
The invention is as follows: “wherein X represents a chromatographic material containing silica or metal oxides, a hybrid inorganic/organic material, a block copolymer group, or combinations thereof; W is chosen from the group consisting hydrogen and hydroxyls, wherein Q is the first substituent that minimizes analyte variation over time when chromatographic conditions are low on water content; T is the second substituent that chromatographically retains analy (b/c), 100, and a?0.
In some embodiments of Q, the following structure (ii), is used:
In some embodiments T has the structure (iii).
The formula for Z is: (CH2)0-12?N?R11R12, ? (CH2)0-12?O?R11, ? (CH2)0-12?S?R, ? (CH2)0-12?N? (CH2)0-12?R11R12, ? (CH2)0-12?O? (CH2)0-12?R11, ? (CH2)0-12?S? (CH2)0-12?R11, ? (CH2)0-12?S(O)1-2? (CH2)0-12?N?R11R12, ? (CH2)0-12?S(O)1-2? (CH2)0-12?O?R11, ? (CH2)0-12?S(O)1-2? (CH2)0-12?S?R11; ? (CH2)0-12?S(O)1-2?(CH2)0-12?N? (CH2)0-12?R11R12, ? (CH2)0-12?S(O)1-2?(CH2)0-12?O? (CH2)0-12, (CH2)0-12?S(O)1-2?(CH2)0-12?S? (CH2)0-12, Polymerization can occur with
In another embodiment, this disclosure is a method of separating a polycyclic aromatic hydrocarbon, a vitamin, or a lipid from a mixture.
In another embodiment, the present disclosure relates to a chromatographic stationary phase having the following structure (i):\n[X](W)a(Q)b(T)c?? (i)
The invention provides that “wherein: X is a chromatographic material containing silica or metal oxides, an inorganic/organic hybrid, a block copolymer group, or combinations thereof; W is chosen from the group consisting hydrogen and hydroxyl and is bound to the surface X; Q is a substituent which minimizes variation of analyte retention over time when chromatographic conditions have low water concentrations; T is a substitute which chromatographically binds the analyte X (b/c), 100, and a?0.
The present disclosure is applicable to another embodiment of a column or capillary or monolithic column or microfluidic apparatus or device for normal phase chromatography. This includes a housing with at least one wall that defines a chamber, an entrance, and an exit. A stationary phase has the same structure as the housing, i.e. The stationary phase is disposed in the housing (i), wherein it is adapted to normal phase chromatography.
The present disclosure is also applicable to a kit that includes a housing with at least one wall defining an interior chamber, and a stationary part having the same structure. The stationary phase has a wall (i) disposed within the housing, which is adapted to normal phase chromatography.Click here to view the patent on Google Patents.