Phosphate Buffer (pH 6.8, Dehydrated) (ChP) - BioReagent

Cat. No.: P1528254

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

Normal

Overview

For pharmaceutical dilution

Specifications

Specifications & Purity

BioReagent

Storage

Room temperature

Shipped In

Normal

Grade

BioReagent

Product Line

Biological Products

Application Protocols

Because this is a dehydrated buffer, application protocols focus on reconstitution and routine lab use rather than immunoassays.

• Reconstitution (general)
  • Add the specified volume of Type 1 water (not specified here; refer to label/CoA), stir until completely dissolved, and verify pH at the intended use temperature. If required, sterile filter through 0.22 μm.
• Typical workflows (literature)
  • Protein sample preparation: Dilute samples to desired ionic strength; include 0–150 mM NaCl if needed for stability.
  • Enzyme assays: Prepare working solutions at 10–100 mM phosphate, pH 6.8; equilibrate temperature; add cofactors/substrates last.
  • HPLC mobile phase (UV): Combine with appropriate organic modifier (e.g., acetonitrile); keep salt concentration within column specifications; filter/degass.
  • Dissolution testing: Prepare per pharmacopeial method at pH 6.8; verify pH at 37 °C; document conductivity and pH per QC SOP.
• Quality checks
  • Measure pH with a calibrated meter (three-point calibration bracketing pH 6.8). Record temperature.
  • Inspect for clarity/particulates; discard if turbidity or precipitate forms unexpectedly.
• Notes
  • Do not assume MS compatibility; phosphate is non-volatile. Avoid mixing concentrated solutions with Ca2+/Mg2+ without consideration of precipitation.

Biological Roles

• Physiological relevance (literature)
  • Phosphate is a central inorganic ion in biology: component of nucleic acids, ATP/ADP, and phospholipids; key in energy transfer and signaling via phosphorylation.
  • Intracellular buffering near neutral pH relies on the H2PO4−/HPO4^2− pair; pKa2 ≈ 7.2 provides strong resistance to pH changes in cytosolic ranges.
• Enzymology considerations
  • Many enzymes tolerate phosphate buffers; however, phosphate can act as a competitive inhibitor or ligand in enzymes with phosphate-binding pockets (e.g., kinases, phosphatases). Validate buffer choice for enzyme kinetics.
  • Metal-dependent enzymes may be influenced by phosphate’s weak metal coordination; Mg2+ and Ca2+ precipitation at higher concentrations must be considered.
• Cell and molecular biology
  • Phosphate-buffered systems support nucleic acid stability and many protein storage scenarios, though some proteins prefer non-phosphate buffers to avoid specific interactions or precipitation with divalent cations.
• Microbiology
  • Phosphate contributes to defined media buffering capacity; for culture work, sterilize by filtration or autoclaving if the complete formulation is compatible. Note that high phosphate can influence microbial physiology and biofilm formation (literature).

Buffer Applications

This product is a dehydrated phosphate buffer formulated to yield pH 6.8 on reconstitution.

• Preparation
  • Follow the container label to reconstitute to the specified final volume/concentration (not specified here; refer to CoA/Spec Sheet). Mix with Type 1 water until fully dissolved. Measure pH at the use temperature.
  • If sterilization is required, filter through 0.22 μm. Autoclaving is generally compatible for phosphate solutions without heat-labile additives (literature).
• Working ranges and design (literature)
  • Effective buffering range: pH 5.8–8.0; optimal near pH 7.2.
  • Henderson–Hasselbalch for phosphate: pH = pKa2 + log10([HPO4^2−]/[H2PO4−]); choose conjugate base/acid ratio accordingly. At pH 6.8, base:acid ≈ 0.40 (25 °C).
  • Typical working concentrations: 10–100 mM for biochemistry; higher for dissolution testing as specified by method.
• Compatibility notes (literature)
  • Avoid high levels of Ca2+/Mg2+—may form insoluble phosphates. If divalent cations are essential, reduce phosphate concentration or consider Good’s buffers.
  • For HPLC, phosphate buffers are excellent for UV detection but are non-volatile and can salt-out with high organic content.
• Example formulations (literature; not specific to this item)
  • 50 mM sodium phosphate, pH 6.8 at 25 °C: combine appropriate amounts of NaH2PO4·H2O and Na2HPO4 to achieve base:acid ≈ 0.40; adjust with small volumes of acid/base if needed.
  • For pharmacopeial dissolution media calling for pH 6.8 phosphate buffer, adhere strictly to the monograph recipe and ionic strength; verify pH at 37 °C.

Green Alternatives

Phosphate buffers are generally considered benign, abundant, and low-toxicity, but they are non-volatile and contribute to eutrophication if released.

• Environmental profile (literature)
  • Advantage: inorganic, low hazard; minimal VOCs; compatible with water-based processes.
  • Caution: phosphate discharge can promote algal blooms; manage effluent and follow local discharge limits.
• Alternative buffers and tradeoffs (literature)
  • Ammonium acetate/formate (volatile): MS-compatible and volatile, simplifying solvent removal; narrower buffering near pH ~4–6 (acetate) or ~3.5–5/formate; weaker near pH 6.8.
  • Good’s buffers (HEPES, MOPS): excellent biochemical performance with low metal binding and low temperature coefficient; not readily biodegradable and more expensive; non-volatile.
  • Bicarbonate/CO2: greener and naturally occurring; pH sensitive to CO2 partial pressure and temperature; less stable in open systems.

| Buffer system | Green aspect | Limitations vs phosphate | | --- | --- | --- | | Phosphate (this product) | Low toxicity, water-based | Non-volatile, eutrophication risk | | Ammonium acetate/formate | Volatile, MS-friendly | pH window not centered at 6.8 | | Bicarbonate/CO2 | Natural, minimal persistence | CO2 control needed; pH drift | | HEPES/MOPS | Stable, low metal binding | Persistence/cost; non-volatile |

• Best practice
  • Use the lowest effective buffer concentration, segregate phosphate-containing waste, and neutralize/collect for appropriate disposal to minimize environmental impact.

Pharmaceutical Uses

• Role in dosage form development (literature)
  • Widely used as a buffer/excipient to control pH in oral liquids, topicals, and parenterals (when compatible), and in lyophilized products to stabilize pH upon reconstitution.
  • Common dissolution medium: pH 6.8 phosphate buffer is frequently specified in pharmacopeial (e.g., ChP/USP/EP) dissolution methods for immediate-release oral dosage forms to simulate intestinal pH. Verify that concentration and composition match the method.
• Analytical quality control
  • Employed as diluent/mobile phase aqueous component for UV-based HPLC assays (not LC–MS due to non-volatility). Filter and degas to protect columns and detectors.
• Manufacturing considerations
  • Non-volatile inorganic salt system; compatible with stainless steel equipment. Avoid mixing concentrated phosphate with calcium-containing excipients or hard water without control to prevent scale/precipitation.
  • Temperature coefficient requires pH verification at process temperature (e.g., 25 °C for preparation; 37 °C for dissolution tests).
• Regulatory context
  • The product name indicates “(ChP)”. Lot-specific compliance to Chinese Pharmacopoeia, if applicable, is not specified here; consult the CoA/Spec Sheet and your method. No medical or clinical use is intended; for research and laboratory use only.

Physical Properties

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Dehydrated state: Free-flowing salt blend, highly water soluble (literature).
• Solution behavior (literature, general for phosphate buffers)
  • Buffering range: Approximately pH 5.8–8.0, optimal near pKa2 ≈ 7.20 at 25 °C.
  • Temperature coefficient: Phosphate pH decreases modestly with increased temperature (≈ −0.002 to −0.003 pH/°C around neutral pH; literature), so measure pH at use temperature.
  • Ionic strength/osmolality: Determined by the intended working molarity (e.g., 10–200 mM typical for biochemistry; literature). Item-specific values are not specified; refer to CoA/Spec Sheet.
  • Solubility: Readily soluble in water; insoluble in most organic solvents (literature).
• Other parameters
  • pKa values (orthophosphoric acid; literature): pKa1 ≈ 2.15, pKa2 ≈ 7.20, pKa3 ≈ 12.35 (25 °C).
  • Density, melting point, refractive index, conductivity cutoffs, UV cutoff: Not applicable or not specified for this dehydrated blend; refer to CoA/Spec Sheet for any lot-specific data.
• Working pH
  • Target pH on reconstitution: 6.8 (per product name) at the concentration and temperature defined by the product’s instructions (not specified here; refer to label/CoA).

Quality & Grades

• Item-specific grade
  • Grade/Purity: BioReagent (per Product Data). This denotes suitability for general biochemical and molecular biology workflows, emphasizing low levels of common biological contaminants. It is not equivalent to clinical/diagnostic grade. For research use only.
• Pharmacopoeial indication
  • The product name includes “(ChP)”, typically indicating alignment with Chinese Pharmacopoeia practices for phosphate buffers (e.g., use as dissolution medium). Exact monograph compliance, concentration, and tolerances are not specified for this item; consult the CoA/Specification Sheet for lot-specific conformity claims.
• Stabilizers and additives
  • None stated. Any anti-caking agents, preservatives, or pH-adjusting components are not specified for this item; refer to CoA/Spec Sheet.
• What to expect from a BioReagent phosphate buffer
  • Trace organics and particulates controlled for routine biochemical assays.
  • Reproducible pH when prepared according to the label at the defined concentration and temperature.
• Recommended verification on receipt
  • Confirm pH at the intended working concentration and temperature (e.g., 25 °C) with a calibrated pH meter.
  • Assess conductivity and osmolarity if these parameters are critical to your application.
  • If using in regulated contexts (e.g., pharmacopeial dissolution testing), retain CoA and verify alignment with the test method’s specified buffer recipe and tolerances.

Reaction & Applications

• Biochemical and analytical applications (typical for phosphate pH 6.8; literature)
  • Protein and enzyme assays near neutral pH where phosphate does not interfere with active sites. Note: phosphate can inhibit certain kinases and enzymes that bind phosphate; verify compatibility.
  • Nucleic acid handling, gel extraction washes, and general sample dilution where ionic strength and pH stability are needed.
  • Chromatography: aqueous component for HPLC/UV detection. Avoid for LC–MS owing to non-volatility.
  • Pharmaceutical quality control: commonly used as dissolution medium at pH 6.8 per many pharmacopeial monographs; ensure buffer recipe and ionic strength match the specific method (consult CoA/specification and method).
• Practical tips
  • Reconstitute with high-purity water at the volume specified on the label (not provided here). Adjust final pH only if allowed by your method; temperature-equilibrate before measurement.
  • Filter (0.22–0.45 μm) and degas for analytical applications to remove particulates and dissolved gases.
  • Avoid mixing concentrated phosphate with solutions rich in Ca2+/Mg2+ to prevent precipitation; add slowly with stirring or chelate if permissible.
• Chemical reactivity considerations (literature)
  • Phosphate buffers can coordinate to metal centers, affecting catalysis in some homogeneous reactions.
  • As a nucleophile/base, phosphate is weak but can participate in phosphoryl transfer biochemistry; generally inert in most organic transformations executed in aqueous media.

Reaction Conditions

General guidance below reflects literature norms for phosphate buffers around pH 6.8; item-specific directions are not provided here and should follow the product label/CoA.

• Enzymatic reactions (literature)
  • Buffer concentration: 10–100 mM; pH 6.6–7.0 for many hydrolases, isomerases, and kinases (verify enzyme-specific preferences).
  • Temperature: 4–40 °C typical; measure pH at the reaction temperature to ensure accuracy.
  • Additives: 0.1–1 M NaCl for ionic strength control; Mg2+ or other cofactors as required—mind phosphate precipitation at higher concentrations.
• Analytical applications
  • HPLC (UV): 10–100 mM phosphate at pH 6.8 commonly used; filter (0.22–0.45 μm) and degas. Avoid for LC–MS due to non-volatility.
  • Dissolution testing: Prepare at prescribed molarity and pH 6.8; equilibrate to 37.0 ± 0.5 °C; verify pH at temperature (per pharmacopeial practice; consult specific method).
• Stability (literature)
  • Aqueous phosphate buffers are stable for days to weeks at 2–8 °C when protected from contamination. Sterile, filtered solutions may be stored longer; always confirm pH before critical use.
• Expected outcomes
  • High pH stability within the buffering range; minimal participation in side reactions under neutral conditions. Verify any enzyme/catalyst compatibility empirically.

Safety & Handling

• GHS classification and pictograms: Not specified for this item; refer to the product SDS for authoritative safety information.
• General hazards (literature, for phosphate salts and buffer powders)
  • Low acute toxicity; may cause mild eye/skin irritation. Dust may irritate respiratory tract. Avoid creating dust clouds.
• Personal protective equipment
  • Wear lab coat, safety glasses, and suitable gloves (e.g., nitrile). Use a dust mask/respirator if airborne particulates may be generated. Handle in a well-ventilated area or fume hood when weighing.
• Incompatibilities and reactivity (general)
  • Strong acids/bases (pH excursions outside buffer range). Phosphate can precipitate with multivalent cations (Ca2+, Mg2+, Ba2+, Sr2+) forming insoluble phosphates; avoid mixing concentrated solutions without consideration of solubility.
  • Avoid contact with aluminum and zinc in acidic/basic conditions due to possible corrosion. No known flammability.
• First-aid (general guidance; defer to SDS)
  • Inhalation: Move to fresh air; seek medical advice if symptoms persist.
  • Skin/eye contact: Rinse with water for several minutes; remove contaminated clothing; obtain medical attention if irritation develops.
  • Ingestion: Rinse mouth; obtain medical advice if unwell.
• Spills and disposal
  • Sweep/HEPA-vacuum solids gently to minimize dust. Dissolve residue with water, collect, and dispose in accordance with institutional and local regulations. Avoid release to surface waters in quantity (phosphate contributes to eutrophication).

Solvent Selection

This product is itself a buffer system; the solvent is typically purified water.

• Water quality
  • Use freshly produced Type 1 (ASTM/CLSI) or HPLC-grade water for analytical and biochemical work to minimize TOC, particulates, and ionic contaminants.
  • Minimize CO2 uptake: prepare in closed vessels, especially for low-ionic-strength buffers, to avoid acidification via carbonic acid.
• Miscibility and use with cosolvents (literature, general)
  • Phosphate buffers are fully miscible with water and many water-miscible organics (methanol, acetonitrile). However, high proportions of organic solvents can shift pH and reduce salt solubility; precipitation may occur above ~40–60% organic, depending on concentration and temperature.
  • Not recommended for LC–MS mobile phases due to non-volatility; consider volatile buffers (ammonium formate/acetate) for MS detection.
• Selection guidance
  • Choose phosphate pH 6.8 for enzyme assays, protein/nucleic acid work, and dissolution tests requiring near-neutral pH and robust buffering.
  • Prefer Good’s buffers (HEPES, MOPS) when minimal metal complexation, lower temperature coefficient, or optical transparency at low UV is crucial.
• Small comparison (literature)
  • Phosphate: strong buffering near neutral, inexpensive; non-volatile, can precipitate with Ca/Mg.
  • HEPES/MOPS: zwitterionic, low metal binding; more costly, non-volatile.

Storage & Reconstitution

• Storage (item-specific)
  • Storage conditions: Room temperature (per Product Data).
  • Shipped: Normal (per Product Data).
• Shelf life and stability
  • Dehydrated inorganic phosphate salts are typically stable for extended periods when kept tightly closed and dry. Lot-specific expiry is not specified for this item; refer to label/CoA.
• Reconstitution
  • Reconstitute with high-purity Type 1 water to the final volume specified on the label (not provided here). Mix until fully dissolved. Verify pH at the intended use temperature (target pH 6.8 per product name).
  • For sterile applications, filter through a 0.22 μm membrane into sterile containers. Avoid CO2 ingress for highest pH stability.
• Storage of prepared solution (literature)
  • Store at 2–8 °C in clean, closed containers. For non-sterile solutions, use within 1–2 weeks as good laboratory practice; sterile, filtered solutions may be stored longer if validated. Always recheck pH before critical use.
  • To minimize microbial growth, prepare fresh as needed or include a suitable preservative if compatible with downstream applications (not provided with this item).
• Handling tips
  • Reseal container promptly after dispensing to prevent moisture uptake and caking.
  • Avoid cross-contamination by using clean, dry scoops and dedicated weighing paper.

Research Use Note: For research use only (per Product Data).

Structure & Identity

This product is a dehydrated, pre-formulated inorganic phosphate buffer blend designed to yield pH 6.8 upon reconstitution with water.

• Item-specific identifiers
  • Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
  • CAS, InChIKey, SMILES: Not specified for this item; refer to CoA/Spec Sheet.
• Nature of material
  • Composition: Dehydrated buffer salts (inorganic phosphates). Exact salt identities and ratios are not specified for this item; refer to CoA/Spec Sheet.
  • Typical constituents (literature): mixtures of sodium and/or potassium phosphate salts (e.g., NaH2PO4/Na2HPO4 or KH2PO4/K2HPO4) adjusted to give pH 6.8 at a stated working concentration.
• Structural features (general chemistry)
  • Inorganic orthophosphate anion PO4^3− is a tetrahedral oxyanion; conjugate acids HPO4^2−/H2PO4^− participate in buffering near pKa2 ≈ 7.2 (literature).
  • No stereocenters; no organic ring systems. Countercations are alkali metals when present (literature).
• 2D description (general)
  • A central phosphorus atom double-bonded to one oxygen and single-bonded to three oxygens (overall tetrahedral), with protonation state depending on pH; charge balanced by alkali metal cations (if present).

Synthetic Utility

• Role in synthetic chemistry (literature)
  • Aqueous phosphate buffer at pH 6.8 is primarily used to control proton activity in water-mediated and biocatalytic reactions (e.g., enzymatic transformations, whole-cell biocatalysis) near neutral pH.
  • Can modulate reaction selectivity in chemoenzymatic cascades and stabilize labile intermediates against acid/base-catalyzed decomposition.
• Compatibility and limitations
  • Phosphate can coordinate to transition metals, occasionally inhibiting catalysts (e.g., in some cross-couplings or oxidation reactions). Evaluate catalyst tolerance before use.
  • Poor choice for reactions demanding strictly anhydrous conditions or volatile buffers (e.g., processes requiring downstream lyophilization without residual salts).
  • May precipitate with divalent metal salts, altering effective catalyst concentration.
• Practical guidance
  • For enzyme-catalyzed reactions, 10–100 mM phosphate at pH 6.8 is common; screen ionic strength for optimal activity (literature).
  • Degas if oxygen-sensitive; maintain constant temperature, as pH drifts with temperature.
  • For extractive workups, inorganic phosphate salts remain in the aqueous phase; plan phase separations accordingly.

Target Specificity

Not applicable. This product is a dehydrated buffer blend and is not an antibody, probe, or affinity reagent. There are no targets, epitopes, clones, or species reactivity associated with this item. For practical use details, see Buffer Applications and Application Protocols.