PS/DVB-SO₃⁻ matrix
40 μm
60 Å
600 m²/g
1.0 meq/g ion exchange capacity
pH 0-14 stable
For alkaline drugs, β-agonists, melamine, and basic metabolites in food, biological fluids, and environmental samples
Availability: In Stock
MCX SPE Cartridge
Description
What is MCX SPE Cartridge?
MCX SPE cartridges are mixed-mode strong cation exchange sorbents combining reversed-phase and ion exchange retention mechanisms.
The sulfonic acid group is covalently bonded to a PS/DVB (polydivinylbenzene) polymer matrix, providing a permanently charged cation exchanger (pKa < 1) with high surface area (600 m²/g). This dual-mode retention allows MCX to effectively extract basic (alkaline) compounds from complex matrices while removing neutral and acidic interferences.
MCX is widely used for
- β-agonists (clenbuterol, ractopamine) in food and feed
- Melamine in milk powder and dairy products
- Amphetamines, opiates, and other drugs of abuse in urine, plasma, and tissue
- Chlorpheniramine maleate, benzodiazepines, and other basic pharmaceuticals
- Basic pesticides and metabolites in environmental water
MCX SPE Retention Mechanism
MCX provides two simultaneous retention modes:
| Mechanism | How it works | When it applies |
| Strong cation exchange | The sulfonic acid group (-SO₃⁻) retains positively charged (protonated) basic compounds via ionic interaction | At loading pH ≤ pKa of analyte – 2 (typically pH 2-6) |
| Reversed-phase (hydrophobic) | The PS/DVB polymer matrix retains non-polar to moderately polar compounds via hydrophobic interaction | Always present, especially useful for neutral or partially charged basic compounds |
This mixed-mode design gives MCX superior selectivity for basic drugs compared to single-mode SCX or C18 sorbents. It also provides excellent acid resistance and stability across the entire pH range (0-14), allowing aggressive conditioning and elution conditions.
Key advantage: MCX can remove the majority of phospholipids from biological samples when used with optimized wash conditions.
Technical Specifications
| Parameter | Value |
| Matrix | PS/DVB (polydivinylbenzene) with covalently bonded sulfonic acid |
| Functional group | -SO₃⁻ (strong cation exchange) |
| Particle size | 40 μm |
| Pore size | 60 Å |
| Surface area | 600 m²/g |
| Ion exchange capacity | 1.0 meq/g |
| pH stability | 0 – 14 (excellent acid resistance) |
| Retention mechanisms | Mixed-mode: cation exchange + reversed-phase |
| Typical applications | Basic drugs, β-agonists, melamine, amphetamines, basic pesticides |
MCX vs SCX vs C18 – Which One Fits Your Application?
| Sorbent | Matrix | Primary Mechanism | Well – suited for | Key Advantage |
| MCX | PS/DVB-SO₃⁻ | Cation exchange + reversed-phase | Basic drugs, metabolites, melamine, β-agonists | Removes phospholipids; pH 0-14 stable; high capacity |
| SCX | Silica-SO₃⁻ | Strong cation exchange (plus moderate hydrophobic) | General basic compounds | Lower cost but less pH stable; silica matrix |
| C18 | Silica-C18 | Reversed-phase only | Neutral and non-polar compounds | Poor retention for charged basic drugs |
Why choose MCX over SCX?
MCX uses a polymer (PS/DVB) matrix instead of silica. This provides:
- Wider pH stability (0-14 vs 2-5 for silica SCX)
- Higher surface area (600 m²/g) for better loading capacity
- No silanol interactions -cleaner extracts for basic analytes
- Superior phospholipid removal -essential for LC-MS/MS bioanalysis
MCX SPE Cartridge Applications by Industry
| Industry / Segment | Typical Matrices | Target Analytes |
| Food safety | Milk powder, dairy products, meat, feed | Melamine, β-agonists (clenbuterol, ractopamine, salbutamol), sulfonamides |
| Clinical & forensic toxicology | Urine, plasma, blood, tissue homogenate | Amphetamines, opiates, cocaine metabolites, benzodiazepines, antidepressants |
| Pharmaceutical bioanalysis | Plasma, serum, urine | Basic APIs, drug metabolites, chlorpheniramine, phenylephrine |
| Environmental monitoring | Surface water, wastewater | Basic pesticides, herbicides, pharmaceutical residues (e.g., propranolol, metoprolol) |
| Biological sample preparation | Bile, tissue homogenate | Basic endogenous compounds, alkaloids |
Standard MCX SPE Workflow (Step-by-Step)
Goal: Retain basic compounds, remove neutrals and acids, elute with basic organic solvent.
| Step | Solvent | Purpose | Critical tip |
| Condition | Methanol → water or dilute buffer (pH 2-6) | Activate sorbent | Do not let cartridge dry after conditioning |
| Load | Acidified sample (pH 2-6, e.g., 2% formic acid in water) | Retain protonated basic analytes | Ensure sample pH ≤ pKa of analyte – 2 |
| Wash | Water or dilute acid (e.g., 2% formic acid in water) | Remove neutral and acidic interferences | For phospholipid removal, add a wash with 5% ammonium hydroxide in 20% methanol (optional) |
| Elute | 5% ammonium hydroxide in methanol (or 2% NH₄OH in 95% methanol/5% water) | Displace cations, recover basic analytes | Collect eluate in low-retention tubes; may evaporate for reconstitution |
Note for melamine analysis: A dedicated protocol with higher ionic strength elution may be used. Contact technical support for application-specific methods.
Ordering Guide – Choose the Right MCX Cartridge Format
| Sorbent mass | Reservoir | Best for | Cat# |
| 30 mg | 1 mL | Method development, trace bioanalysis, low sample volume | 15011149 |
| 60 mg | 1 mL | Routine urine/plasma screening (1-2 mL sample) | 15011150 |
| 30 mg | 3 mL | Larger reservoir for automation, low loading | 15011151 |
| 60 mg | 3 mL | Standard bioanalysis, general purpose | 15011152 |
| 150 mg | 6 mL | Higher loading, dirty matrices (e.g., tissue homogenate) | 15011153 |
| 200 mg | 6 mL | Environmental water (100-500 mL), food extracts | 15011154 |
| 500 mg | 6 mL | High loading, large-volume water (>500 mL), industrial samples | 15011155 |
| 500 mg | 12 mL | Large-volume biological fluids, preparative cleanup | 15011156 |
| 1 g | 12 mL | Very high loading, bulk processing | 15011157 |
All formats compatible with standard SPE manifolds, vacuum systems, and automated SPE workstations (Thermo, Horizon, Biotage, etc.).
Download PDF Datasheet
Technical Specifications Summary
| Parameter | Value |
| Matrix | PS/DVB-SO₃⁻ (polymer-based) |
| Particle size | 40 μm |
| Pore size | 60 Å |
| Surface area | 600 m²/g |
| Ion exchange capacity | 1.0 meq/g |
| pH stability | 0-14 |
| Recommended loading pH | 2-6 (acidic) |
| Recommended elution solvent | 5% NH₄OH in methanol |
Frequently Asked Questions
What is the difference between MCX and SCX SPE cartridges?
MCX uses a polymer (PS/DVB) matrix with sulfonic acid groups, providing mixed-mode retention (cation exchange + reversed-phase) and excellent pH stability (0-14). SCX is silica-based with only cation exchange and narrower pH range (2-7.5). MCX also offers higher surface area and better phospholipid removal for LC-MS/MS bioanalysis.
Can MCX be used for melamine extraction?
Yes. MCX is the standard sorbent for melamine in milk powder and dairy products (e.g., Chinese national standard GB/T 22388). The strong cation exchange retains protonated melamine, while the PS/DVB matrix removes hydrophobic interferences.
What pH should be used for loading MCX?
Load at pH 2-6. For basic analytes (pKa 8-10), use 2% formic acid in water to ensure full protonation. Do not exceed pH 7 during loading, or basic compounds may lose charge and breakthrough.
Does MCX remove phospholipids from biological samples?
Yes. MCX cartridges are designed to remove up to 99% of phospholipids when used with an optimized wash step (e.g., 5% ammonium hydroxide in 20% methanol). This reduces ion suppression and extends LC-MS/MS column lifetime.
Do you provide batch-specific COA?
Yes. COA including particle size, surface area, and ion exchange capacity verification is available for each production lot.
Can MCX be used with automated SPE systems?
Yes. All our MCX cartridges (1 mL, 3 mL, 6 mL, 12 mL) are compatible with major automated SPE platforms (Thermo, Horizon, Biotage, etc.).
Why Procurement Teams Choose Hawach MCX SPE Cartridges
- Direct replacement for Waters Oasis MCX, Agilent Bond Elut Plexa PCX -same protocols, no method revalidation
- Cost-effective -30-40% lower price than leading brands with equivalent performance
- High surface area (600 m²/g) -superior loading capacity
- Polymer matrix -pH 0-14 stability, no silanol interactions
- In-stock -standard formats ship within 3-5 business days
- OEM & private label -custom cartons, pouches, bulk sorbent, and private labeling
- Full documentation -COA and lot traceability for GMP/GLP compliance
- Free samples for qualified labs -test before you buy
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