Solid Phase Extraction Products PAGE: 1. Introduction of Solid Phase Extraction (SPE) Why Choose Nano-Micro Tech SPE

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Introduction of Solid Phase Extraction (SPE)

SPE has been used increasingly in chemical analysis and purification broadly, and become the most popular technology of sample preparation. It is employed primarily in purification or concentration of samples before analysis in gas chromatography and liquid chromatography. SPE initially used bonded silica gel as the base sorbents. As technology evolves, polymer microspheres for SPE sorbents are gaining popularity and acceptance because of the shortcomings of bonded silica such as poor pH stability and low absorption capacity.

SPE is a column chromatographic analysis process bearing much similarity to high performance liquid chromatography (HPLC) in the mechanism of separation and choice of reagents and solvents. When a sample passes through the extraction column filled with a sorbent, a part or all of the constituents interact with the sorbent and are retained in the column. A solvent or mixture of solvents is then used to wash out interferences. The target analyte is then quickly eluted out of the column by a desired solution of reduced volume. The goal of fast separation, purification, and concentration is therefore achieved. SPE can be carried out with various types of sorbents to perform extraction and separation of different analytes. Depending on the nature of the sorbents, SPE extraction materials can be divided into normal phase sorbents, reverse phase sorbents and ion exchange sorbents.

Why Choose Nano-Micro Tech SPE

Nano-Micro Tech is the world’s first and only company that supplies monodisperse SPE sorbents, which has already impacted the current SPE market traditionally relied on sorbent particles of broad size distribution or irregular shape. In the past, monodisperse sorbents are only used in high-end chromatography and analysis columns. Under optical microscope (Figure 2), the first generation silica sorbents are irregular in shape and the second generation spherical polymer particles are broad in size distribution. The new generation Uni series SPE sorbents by Nano-Micro Tech is spherical with a uniform particle size. They also have a high surface area and high density of functional groups on the particle surface.

Nano-Micro Tech is taking the lead in advancing the SPE technology. Using the latest techniques in microparticle preparation and surface modification, a series of highly efficient Nano-Micro Uni SPE sorbents have been developed. They have accurate particle sizes, narrow size distribution, largesurface area, very high chemical stability, broad application pH range, optimized pore size, and uniform surface functional groups. Uni SPE sorbents therefore readily satisfy the need for high sensitivity in analyzing different materials. Nano-Micro Tech’s unique particle technology not only ensures the consistency of the sorbents size and internal pore structure, but also brings about high recovery and good reproducibility for specific adsorption. The monodisperse particles provide benefits of even flow characteristics of the solvents and samples moving through the column. They also prevent the sorbent and analyte from breakthrough and minimize solvent usage.

Figure1. Impact of broad particle size distribution on flow.

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Particle size analysis shows that Nano-Micro Uni particles are monodisperse with Coefficient of Variation (CV) less than 3%, whereas those of the competitors have a broad particle size distribution from 10 to 50 µm with a CV larger than 10%. The monodisperse Nano-Micro Uni particles provide outstandingly high recovery, loading, selectivity, reproducibility, and elution concentration plus a reduction in solvent usage.

As demonstrated and proven by customers, Nano-Micro Uni series columns have advantages of higher loading and recovery, lower solvent usage, faster flow rate, more concentrated elution and reproducibility than those of the competitors. Nano-Micro Tech’s advanced manufacturing facilities and instruments as well as reliable procedures of quality control ensure the quality and reproducibility of the products.

z World’s only supplier of monodisperse SPE sorbents.

z Recovery equal to or higher than globally known brand name SPE columns. z High quality SPE sorbents similar to those employed in chromatography. z Highest performance and consistent quality in SPE products

Table1. Guide to the selection of Nano-Micro Tech SPE columns

Figure 3. Particle size distribution of Nano-Micro Uni (Green) and competitor (Red) SPE sorbents.

Samples with positive charge or acidic Samples with negative charge or basic

Samples neutral without charge Samples soluble in

aqueous or highly polar solvents

UniPS-SAX UniPS-SCX UniBPC-SCX Use UniPS-SCX and UniPS-SAX jointly to remove charged impurities

Samples soluble in organic solvents, mild or no polarity

Samples with positive charge or acidic Samples with negative charge or basic

Samples neutral without charge

UniPS-SAX or UniBPC

UniPS-SCX or UniBPC

Uni BPC

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It is important to select suitable Nano-Micro Tech Uni SPE products based on the need and sample properties. A proper selection of SPE columns will substantially facilitate the extraction process leading to satisfactory results. Listed in Table 1 are different types of sorbents for selection; Table 2 are different sizes of SPE columns and amounts of sorbents. For questions, please contact Nano-Micro Tech service department.

Table2. Sample Volume vs. SPE Column Specifications

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UniBPC Series, Water-Wettable Reverse Phase Sorbents

Formulated specifically by Nano-Micro Tech, UniBPC SPE sorbents are produced with a special polymerization technique. They are reverse phase sorbents wettable by water with balanced hydrophilicity and hydrophobicity capable of satisfying most SPE needs. Monodisperse microspheres in UniBPC SPE sorbents are made with outstanding ability to retain polar compounds. They are quite suitable for the isolation of compounds of no or medium polarity. Because of a large surface area, UniBPC has a very high adsorption capacity which not only effectively reduces breakthrough, but also substantially decreases the volume of eluent passing through a compact column thereby raising the elution stability and speed. UniBPC is suitable for separation and isolation of a very wide range of organic compounds such as barbiturates, antibiotics, phthalazines, caffeine, drugs, dyes, aromatic oil, lipid soluble vitamins,fungicides, herbicides, agriculture chemicals, hydrocarbon compounds, phenols, phthalates, steroids,surfactants, water-soluble vitamins, etc. ●

UniPS-SCX Series, Mixed-mode Cation Exchange and Reverse Phase Sorbents

UniPS-SCX SPE sorbents are polymer microspheres with sulfate groups. Based on a mixed mode of strong ion exchange and hydrophobicity interaction, their function is to separate and analyze basic compounds such as amphetamines, melamine, chloropheniramine, phencyclidine, etc.

Because of the high surface area of the microspheres and ion exchange capacity of sulfate groups, UniPS-SCX can effectively and steadily adsorb basic compounds, and retain them well in comparison with known products from the current leading companies.

UniPS-SCX sorbents hold the stability of the bonded phase across the entire pH range of 1 to 14 and greatly widen the conditions for separation exploration. Furthermore, UniPS-SCX SPE columns have the unique monodisperse sorbents which enhance flow rate stability and improve recovery thus providing good product reproducibility on large scale manufacturing.

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UniPS-SAX Series, Mixed-mode Strong Anion Exchange and Reverse Phase Sorbents

UniPS-SAX SPE columns are used for the isolation and purification of acidic compounds in basic or neutral medium. Based on polymer microspheres with quaternary ammonium functional groups, UniPS-SAX has a mixed mode of operation combining strong anion exchange and hydrophobicity. UniPS-SAX can quickly and steadily recover acidic compounds from the samples for purification, for example, estrone, adenine, nucleosides, etc.

Sample Volume Column Spec., cc/mg

1-10 mL 1 / 30

10-100 mL 3 / 60

100-500 mL 6 / 200

500 mL - 1000 mL 6 / 500

* For normal phase and reverse phase SPE,

the amount of analyte to be extracted usually does not exceed 5% of SPE sorbent. For ion exchange SPE, the capacity of ion exchange resin also needs to be considered. The above table is for reference only.

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SPE Operating Procedures

Sorbent Conditioning/Activation: C

ondition SPE column is to completely wet the surface of the sorbent and prepare the sorbent to work with the sample. A properly conditioned sorbent ensures that all surface area is available for interaction with analyte to enhance analysis reproducibility. A typical step begins with rinsing the column bed with a certain amount of organic solvent, followed by a solvent similar in nature to the solvent used to dissolve the sample for analysis. After conditioning the sorbent, keep the SPE column from drying out as it may lower recoveries.

Sample Loading/Application:

Add the sample in the form of liquid and pass it through conditioned SPE column. Because of one or more types of interaction, for example, non-polar interaction with reverse phase column sorbent or charge interaction with ion exchange sorbent, the target analyte and some interference will be absorbed by the SPE sorbents. The pH and salt concentration of the sample loading liquid should be adjusted to increase the retention of the target analyte and reduce the absorption of interferences in the sorbent. Before loading the sample liquid into the extraction column, it should be filtered or centrifuged to avoid plugging the frit.

It is important to control the flow rate when loading the sample. If the flow rate is too high, the pulling force from the mobile liquid could be stronger than the retention exerted by the sorbent especially in ion exchange interaction resulting in breakthrough. Nano-Micro Tech sorbent is composed of monodisperse microspheres with very high retention ability. Even under high flow rate, it still maintains a strong interaction between the sorbent and the retained analyte without incurring any recovery loss.

Washing:

Use a solvent with proper strength for washing the extraction column. The purpose is to rinse interferences through the column while leaving the target analyte in the column. To reach that goal the strength of the solvent should be strong to remove the absorbed interferences, but also weak enough to leave behind the retained analyte. A commonly used solvent for washing is water or a mixture of water and organic solvent.

Elution:

Use a solvent or mixture of solvents capable of eluting the target analyte off the sorbents. This step has a strong effect on the recovery. It requires an accurate control of the amount and flow rate of the eluent to ensure the reproducibility of the separation. The strength of the eluent is also important. A strong eluent may remove some intentionally retained interference, whereas a weak eluent may not break up the retention of the target analyte on the sorbent. To increase the analyte concentration or change solvents, the collected eluent containing the target analyte can be dried by blowing nitrogen over it and then re-dissolve the analyte in an appropriate solvent.

* For purification of samples, only the first three steps are needed. In the third step, the analyte flows out the column with sample solvent while leaving the interferences on the sorbent.

Uni SPE sorbents

Uni SPE columns

Nano-Micro Tech provides a complete line of SPE sorbents as well as packing columns.

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Table 3. High Performance Solid Phase Extraction Sorbents

Name Characteristics Application

Uni BPC

Matrix: PolyTATO/St Monodisperse reverse phase sorbent with balanced hydrophilic/hydrophobic surface, extracting polar and non-polar compounds such as Naproxen, Ibuprofen, Fenoprofen, Indomethacin, Caffeine, Theobromine, Doxepin and many more; Corresponding to Waters Oasis HLP or Phenomenex Strata X.

Particle Size: 10, 20, 30, 40, 50, 60µm Surface Area: 850 m2/g

Average Pore Size: 300 Å

UniPS RPC-100

Matrix: PS/DVB

Monodisperse polyaromatic sorbent for rapid adsorption of hydrophobic compounds such as phenols, surfactants, ethidium bromide, antibiotics, amino acids, and peptides, etc.; Corresponding to Varian Bont Elut LMS, Bond Elut PPL or PLRP. Particle Size: 3, 5, 10, 20, 30, 40, 50µm

Surface Area: 800 m2/g Average Pore Size：100 Å

UniPS RPC-300

Matrix: PS/DVB

Monodisperse polyaromatic sorbent for rapid adsorption of hydrophobic compounds such as phenols, surfactants, ethidium bromide, antibiotics, amino acids, and peptides, etc.; Corresponding to Varian Bont Elut LMS, Bond Elut PPL or PLRP. Particle Size: 3, 5, 10, 20, 30, 40, 50µm

Surface Area: 700 m2/g Average Pore Size：300 Å

UniMC-RPC

Matrix: Polyacrylic

Monodisperse aliphatic sorbent used for absorption and purification of insulin, fulvic and humic compounds, and antibiotics. Ionic species can be retained through hydrophobic and polar interactions used under isocratic conditions.

Average Pore Size: 300 Å

Uni BPC-SCX

Matrix: PolyTATO/St-SO3H

Monodisperse mixed-mode sorbent with both reversed and strong cationic exchanger function, commonly used for clean up of basic compounds such as Amphetamine, Melamine, Chlorpheniramine, Methadone, Phencyclidine etc.; Corresponding to Waters Oasis MCS, Phenomenex Strata-X-C.

Particle Size: 5, 10, 20, 30, 40, 50, 60µm Surface Area: 850 m2/g

Average Pore Size: 300 Å Ion Capacity: 1 meg/g

UniPS-SCX

Matrix: PS/DVB-SO3H

Monodisperse mixed-mode sorbent with both reversed and strong cation exchanger function, commonly used for clean up of basic compounds such as Amphetamine, Melamine, Chlorpheniramine, Methadone, Phencyclidine etc.; Corresponding to Waters Oasis MCS, Phenomenex Strata-X-C.

Particle Size: 5, 10, 20, 30, 40, 50µm Surface Area：700 m2/g

UniPS-SAX

Matrix: PS/DVB-NR3+ Cl

Monodisperse mixed-mode sorbent with both reversed interaction and strong anion function used for fractionation of acidic compounds such as Ortho-phosphotyrosine, Estrone Sulfate, Adenine Particle Size: 5, 10, 20, 30, 40, 50µm

Surface Area：700 m2/g Average Pore Size: 300 Å

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Table 3. High Performance Solid Phase Extraction Sorbents

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Name Characteristics Application

Uni BPC-SAX

Matrix: PolyTATO/St- NR3+Cl

Monodisperse mixed-mode sorbent with both reversed interaction and strong anion function used for fractionation of acidic compounds such as Ortho-phosphotyrosine, Estrone Sulfate, Adenine Nucleotides from basic or neutral impurities.

Average Pore Size: 300 Å Ion Capacity：0.3 meg/g

UniMC-SAX

Matrix: Polyacrylic-Quaternary Amine

Monodisperse strong anion sorbent used for purification of strong acid compounds.

Particle Size: 10, 20, 30, 40, 50µm Surface Area: 300 m2/g

Average Pore Size: 300 Å Ion Capacity: 2.0 meg/g

UniPS-WAX

Matrix: PS/DVB-NH2

Monodisperse mixed-mode sorbent with both reversed interaction and weak anion function used for fractionation of acidic compounds such as Ortho-phosphotyrosine, Estrone Sulfate, Adenine Nucleotides from basic or neutral impurities. Particle Size: 5, 10, 20, 30, 40, 50µm

Surface Area: 700 m2/g Average Pore Size: 300 Å Ion Capacity: 0.3 meg/g

UniMC-WAX

Matrix: Polyacrylic-NH2

Weak anion sorbent used for purification of strong acid compounds.

Particle Size: 10, 20, 30, 40, 50µm Surface Area: 300 m2/g

UniPS-WCX

Matrix: PS/DVB-COOH

Monodisperse mixed-mode sorbent with both reversed interaction and weak cationic exchanger with carboxylic acid group used for isolation and purification of cytochrome C, amines, drugs, metal ions, thrombin etc.

UniMC-WCX

Matrix: Polyacrylic-COOH

Monodispersed polyacrylic weak cationic exchanger with carboxylic acid group used for isolation and purification of cytochrome C, amines, drugs, metal ions, thrombin etc.

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Table 4. SPE chromatographic column

Product Name Matrix

Particle Size Pore Size _Functional

Group Column Specification

μm Å BPC60 PolyTATO/St 50-150 400 30mg/1cc 60mg/3cc 200mg/6cc 500mg/6cc Uni BPC60 PolyTATO/St 60 400 30mg/1cc 60mg/3cc 200mg/6cc 500mg/6cc Uni BPC40 PolyTATO/St 40 300 30mg/1cc 60mg/3cc 200mg/6cc 500mg/6cc Uni BPC30 PolyTATO/St 30 300 30mg/1cc 60mg/3cc 200mg/6cc 500mg/6cc Uni PS40 PS/DVB 40 300 30mg/1cc 60mg/3cc 200mg/6cc 500mg/6cc BPC60-SCX PolyTATO/St 50-150 400 -SO3H 30mg/1cc 60mg/3cc 200mg/6cc 500mg/6cc

Uni BPC60-SCX PolyTATO/St 60 400 -SO3H 30mg/1cc 60mg/3cc

200mg/6cc 500mg/6cc

Uni PS40-SCX PS/DVB 40 300 -SO3H 30mg/1cc 60mg/3cc

200mg/6cc 500mg/6cc BPC60-SAX PolyTATO/St 50-150 400 -NR3+Cl- 30mg/1cc 60mg/3cc

200mg/6cc 500mg/6cc Uni BPC60-SAX PolyTATO/St 60 400 -NR3+Cl- 20mg/1cc 60mg/3cc

200mg/6cc 500mg/6cc

Uni PS40-SAX PS/DVB 40 300 -NR3+Cl- 30mg/1cc 60mg/3cc

200mg/6cc 500mg/6cc BPC60-WCX PolyTATO/St 50-150 400 -COOH 30mg/1cc 60mg/3cc

200mg/6cc 500mg/6cc

Uni BPC60-WCX PolyTATO/St 60 400 -COOH 30mg/1cc 60mg/3cc

200mg/6cc 500mg/6cc

Uni BPC40-WCX PolyTATO/St 40 300 -COOH 30mg/1cc 60mg/3cc

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Uni PS40-WCX PS/DVB 40 300 -COOH 30mg/1cc 60mg/3cc 200mg/6cc 500mg/6cc

BPC60-WAX PolyTATO/St 50-150 400 -NR2 30mg/1cc 60mg/3cc

200mg/6cc 500mg/6cc

Uni BPC60-WAX PolyTATO/St 60 400 -NR2 30mg/1cc 60mg/3cc

200mg/6cc 500mg/6cc

Uni PS40-WAX PS/DVB 40 300 -NR2 30mg/1cc 60mg/3cc