Splitted tubing apparatus for gradient high performance liquid chromatography

A low flow gradient high performance liquid chromatography apparatus comprising:

• a line of components connected so a first mobile phase enters said components in the following order;
• (1) a pump (P1), 2) an injector (I), 3) a switching valve (V), 4) a column for concentrating components (M), 5) the switching valve (V), 6) a solvent mixing device (MC), 7) a split tubing apparatus (ST) comprising
• a solvent inlet part connected by at least one tube to a split tubing part split into a plurality of two or more tubes, and a solvent outlet part connected by at least one tube to the split tubing part split into a plurality of two or more tubes;
• and
• 8) the switching valve (V):
• and
• another line of components connected so a second mobile phase enters said components in the following order;
• 1) a pump (P2), 2) the switching valve (V), 3) said split tubing apparatus (ST), 4) the solvent mixing device(MC), 5) the switching valve (V), 6) the column for concentrating components (M), 7) the switching valve (V), 8) a separating column (C), and 9) a detector (D).

A low flow gradient high performance liquid chromatography apparatus comprising:

• a line of components connected so a first mobile phase enters said components in the following order;
• 1) a pump (P1), 2) an injector (I), 3) a switching valve (V), 4) a column for concentrating components (M), 5) the switching valve (V), 6) a split tubing apparatus (STM) and 7) the switching valve (V):
• and
• another line of components connected so a second mobile phase enters said components in the following order;
• 1) a pump (P2), 2) the switching valve (V), 3) said split tubing apparatus (STM), 4) the switching valve (V), 5) the column for concentrating components (M), 6) the switching valve (V), 7) a separating column (C), and 8) a detector (D)
• wherein said split tubing apparatus (STM) comprises at least one tube connected together between a solvent inlet part and a split tubing part split into a plurality of two or more tubes and at least one tube connected between the split tubing part and a solvent outlet part via a connector (X) and a connector (Y), respectively;
• and wherein the connector (Y), which is joined with the plurality of split tubes, has a function for sufficiently mixing solvents.

A low flow gradient high performance liquid chromatography apparatus comprising:

• a line of components connected so a first mobile phase enters said components in the following order;
• 1) a pump (P1), 2) an injector (I), 3) a switching valve (V), 4) a column for concentrating components (M), 5) the switching valve (V), 6) a solvent mixing device (MC), 7) a split tubing apparatus (ST) comprising
• a solvent inlet partconnected by at least one tube to a split tubing part split into a plurality of two or more tubes, and
• a solvent outlet part connected by at least one tube to the split tubing part split into a plurality of two or more tubes;
• and
• 8) the switching valve (V) so that both the split tubing apparatus and the solvent mixing device can be filled with the first mobile phase:
• and
• another line of components connected so a second mobile phase enters said components in the following order;
• 1) a pump (P2), 2) the switching valve (V), 3) the split tubing apparatus (ST), 4) the solvent mixing device (MC), 5) the switching valve (V), 6) the column for concentrating components (M), 7) the switching valve (V), 8) a separating column (C), 9) and a detector (D).

A low flow gradient high performance liquid chromatography apparatus comprising:

• a line of components connected so a first mobile phase enters said components in the following order;
• 1) a pump (P1), 2) an injector (I), 3) a switching valve (V), 4) a column for concentrating components (M), 5) the switching valve (V), 6) a split tubing apparatus (STM) comprising
• at least one tube connected together between a solvent inlet part and a split tubing part split into a plurality of two or more tubes and at least one tube connected between the split tubing part split into a plurality of two or more tubes and a solvent outlet part via a connector (X) and a connector (Y), respectively;
• and
• 7) the switching valve (V);
• wherein the connector (Y), which is joined with the plurality of split tubes has a function for sufficiently mixing solvents:
• and
• another line of components connected so a second mobile phase enters said components in the following order;
• 1) a pump (P2), 2) the switching valve (V), 3) the split tubing apparatus (STM), 4) the switching valve (V), 5) the column for concentrating components (M), 6) the switching valve (V), 7) a separating column (C), and 8) a detector (D).

A low flow gradient high performance liquid chromatography apparatus, which comprises:

• a separation column and a pump (P) for feeding a mobile phase into a split tubing apparatus;
• wherein said split tubing apparatus comprises
• a solvent inlet part;
• a split tubing part split into a plurality of two or more tubes;
• a solvent outlet part;
• a connector (X);
• and
• a connector (Y),
• wherein at least one tube is connected together between the solvent inlet part and the split tubing part split into a plurality of two or more tubes via the connector (X) and wherein the split tubing part split into a plurality of two or more tubes is connected to the connector (Y) and wherein at least one tube is connected together between the connector (Y) and the solvent outlet part;
• wherein said low flow gradient high performance liquid chromatography apparatus is capable of eluting a target component from said separation column according to an arbitrary gradient-elution linear line or curve by feeding a mobile phase with a different composition, and
• wherein the solvent outlet part is connected by a tube to a solvent mixing device thereby allowing a mobile phase discharged from the tube of the solvent outlet part to flow into the solvent mixing device.

A method of eluting a sample comprising:

• feeding a mobile phase into a split tubing apparatus followed by a separation column;
• wherein said split tubing apparatus comprises
• a solvent inlet part;
• a split tubing part split into a plurality of two or more tubes;
• a solvent outlet part;
• a connector (X);
• and
• a connector (Y),
• wherein at least one tube is connected together between the solvent inlet part and the split tubing part split into a plurality of two or more tubes via the connector (X) and wherein the split tubing part split into a plurality of two or more tubes is connected to the connector (Y) and wherein at least one tube is connected together between the connector (Y) and the solvent outlet part;
• eluting a target component from said separation column according to an arbitrary gradient-elution linear line or curve by feeding a mobile phase with a different composition, and
• flowing a mobile phase discharged from the tube of the solvent outlet part into a solvent mixing device.

A method of analyzing components being present in trace amounts, which comprises the steps of:

• feeding a mobile phase into a split tubing apparatus followed by a separation column by a pump (P);
• wherein said split tubing apparatus comprises
• a solvent inlet part;
• a split tubing part split into a plurality of two or more tubes;
• a solvent outlet part;
• a connector (X);
• and
• a connector (Y),
• wherein at least one tube is connected together between the solvent inlet part and the split tubing part split into a plurality of two or more tubes via the connector (X) and wherein the split tubing part split into a plurality of two or more tubes is connected to connector (Y) and wherein at least one tube is connected together between connector (Y) and the solvent outlet part;
• sequentially filling the solvent inlet part, the split tubing part split into a plurality of two or more tubes, and the solvent outlet part with the mobile phase;
• eluting a target component from a separation column according to an arbitrary gradient-elution linear line or curve by feeding a mobile phase with a different composition, and
• flowing a mobile phase discharged from the tube of the solvent outlet part into a solvent mixing device.

A method of analyzing components being present in trace amounts in a sample with a low flow gradient high performance liquid chromatography apparatus, wherein said low flow gradient high performance liquid chromatography apparatus comprises:

• a line of components connected so a first mobile phase enters said components in the following order;
• 1) a pump (P1), 2) an injector (I), 3) a switching valve (V), 4) a column for concentrating components (M), 5) the switching valve (V), 6) a solvent mixing device (MC), 7) a split tubing apparatus (ST), and 8) the switching valve (V):
• and
• another line of components connected so a second mobile phase enters said components in the following order;
• 1) a pump (P2), 2) the switching valve (V), 3) said split tubing apparatus (ST), 4) the solvent mixing device (MC), 5) the switching valve (V), 6) the column for concentrating components (M), 7) the switching valve (V), 8) a separating column (C), and 9) a detector (D):
• wherein said method comprises the steps of:
• feeding a first mobile phase from the pump (P1);
• injecting a solution of the sample from the injector (I);
• supplying the sample to the column for concentrating components (M) while diluting the sample with the first mobile phase, so that a target component in the sample is captured in the column for concentrating components (M);
• switching the valve (V);
• discharging the second mobile phase from the pump (P2) to the split tubing apparatus (ST), the solvent mixing device (MC), the column for concentrating components (M), the separating column (C), and the detector (D);
• wherein the first mobile phase and the second mobile phase are mixed in the split tubing apparatus (ST) and form a step gradient and as the mixture of the first and second mobile phases pass through the mixing device (MC), the gradient becomes linear or linear-like to release the captured target component from the column for concentrating components (M) so that a sample band including the released target component is introduced in the separating column (C);
• wherein said split tubing apparatus (ST) comprises
• solvent inlet part,
• a split tubing part split into a plurality of two or more tubes,
• a solvent outlet part,
• a connector (X), and
• a connector (Y)
• wherein at least one tube is connected together between the solvent inlet part and the split tubing part split into a plurality of two or more tubes via the connector (X) and wherein the split tubing part split into a plurality of two or more tubes are connected to connector (Y) and wherein at least one tube is connected together between connector (Y) and the solvent outlet part.

A method of analyzing components being present in trace amounts in a sample with a low flow gradient high performance liquid chromatography apparatus, wherein said low flow gradient high performance liquid chromatography apparatus comprises:

• a line of components connected so a first mobile phase enters said components in the following order;
• 1) a pump (P1), 2) an injector (I), 3) a switching valve (V), 4) a column for concentrating components (M), 5) the switching valve (V), 6) a split tubing apparatus (STM) and 7) the switching valve (V):
• and
• another line of components connected so a second mobile phase enters said components in the following order;
• 1) a pump (P2), 2) the switching valve (V), 3) said split tubing apparatus (STM), 4) the switching valve (V), 5) the column for concentrating components (M), 6) the switching valve (V), 7) a separating column (C), and 8) a detector (D):
• wherein said method comprises the steps of:
• feeding a first mobile phase from the pump (P1);
• injecting a solution of the sample from the injector (I);
• supplying the sample to the column for concentrating components (M) while diluting the sample with the first mobile phase, so that a target component in the sample is captured in the column for concentrating components (M);
• switching the valve (V);
• discharging the second mobile phase from the pump (P2) to the split tubing apparatus (STM), the column for concentrating components (M), the separating column (C), and the detector (D);
• wherein the first mobile phase and the second mobile phase are mixed in the split tubing apparatus (STM) and form a linear or linear-like gradient to release the captured target component from the column for concentrating components (M) so that a sample band including the released target component is introduced in the separating column (C);
• wherein the second mobile phase flows through the split tubing apparatus (STM) in an opposite direction to that of the sample;
• wherein said split tubing apparatus (STM) comprises at least one tube connected together between a solvent inlet part and a split tubing part split into a plurality of two or more tubes and at least one tube connected between the split tubing part and a solvent outlet part via a connector (X) and a connector (Y), respectively, and wherein the connector (Y), which is joined with the plurality of split tubes has a function for sufficiently mixing solvents.