CR Standard

Foundational GC Columns for Versatile Analytical Success

Overview

The CR Standard columns are the workhorse capillary GC phases, offering a broad polarity spectrum from non-polar to polar. They are derived from industry-standard stationary phases and provide robust performance for routine and advanced analyses. These columns are fully synthetic fused-silica capillaries with crosslinked stationary phases, ensuring solvent rinsability and longevity. The CR Standard range is positioned as a versatile, high-quality solution for laboratories that require consistent results across a wide variety of sample types, from volatile solvents to heavy semivolatile compounds. Scientific reliability is matched with commercial practicality – these columns are cost-effective yet deliver performance on par with leading general-purpose GC columns.

Comparison Table – CR Standard vs Typical Columns

Parameter	CR Standard	Generic Columns
Deactivation Quality	Advanced Silanol Shielding	Basic or inconsistent
Phase Availability	Full non-polar to polar	Often limited to 1–2
Batch Reproducibility	High (QA Certificate)	Variable
Film Thickness Options	Extensive (0.1–5 µm)	Limited
Inertness with Active Compounds	Excellent	Moderate to Poor
MS Compatibility	Optimized (low bleed)	May bleed at high temp

Phase Chemistries (Complete List):

The CR Standard range includes multiple phase chemistries to cover different polarity needs. Each phase is equivalent to well-known industry GC phases (with USP code classifications) and is designated by its unique phase number:

Phase Name	Stationary Phase	Polarity	USP Code(s)	Max Temp (°C)	Key Applications
CR-1	100% Methyl Polysiloxane	Apolar	G1, G2, G38	350	Hydrocarbons, solvents, esters, fatty acid methyl esters (FAMEs)
CR-5	5% Phenyl / 95% Methyl Polysiloxane	Low Polarity	G27, G36	340	Semivolatiles, essential oils, flavor/fragrance analysis
CR-35	35% Phenyl / 65% Methyl Polysiloxane	Mid Polarity	G28, G32, G42	340	Aromatics, PAHs, phenols, complex petrochemicals
CR-1701	14% Cyanopropylphenyl / 86% Methyl Polysiloxane	Medium Polarity	G46	280–290	Residual solvents (USP ), polar volatiles
CR-17	50% Phenyl / 50% Methyl Polysiloxane	High Mid-Polarity	OV-17 equivalent	300–320	Halogenated compounds, pesticides, high-boiling aromatics
CR-624	6% Cyanopropylphenyl / 94% Methyl Polysiloxane	Low-Mid Polarity	G43	260	Purge & trap VOCs, industrial solvents, EPA 624 methods
CR-Wax	Polyethylene Glycol (PEG)	Polar	G16	250	Alcohols, glycols, polar volatiles, food aroma compounds
CR-SE52	5% Phenyl / 95% Methyl Polysiloxane (legacy)	Low Polarity	Legacy Method Match	330	Legacy regulated methods requiring SE-52 chemistry
CR-SE54	5% Phenyl / 1% Vinyl / 94% Methyl Polysiloxane	Low Polarity	Legacy Method Match	340	Trace organics, ECD-compatible, high-purity method compliance

CR-1 – 100% methyl polysiloxane (100% dimethylsiloxane polymer). A truly apolar phase, CR-1 is analogous to USP G1/G2 phasesIt exhibits extremely low stationary phase polarity and high thermal stability (T_max ~350 °C).
CR-5 – 5% phenyl, 95% methyl polysiloxane. A low-polarity phase (slightly more polar than CR-1), equivalent to classic 5% diphenyl columns (USP G27/G36)Balances volatility range and slight aromatic selectivity; T_max ~340 °C.
CR-35 – 35% phenyl, 65% methyl polysiloxane. A mid-polarity phase providing greater aromatic/polar selectivity. This phase is crossbonded and classified under USP codes G28, G32, G42. T_max ~340 °C.
CR-1701 – 14% cyanopropylphenyl, 86% methyl polysiloxane. A medium-polarity phase (often called “1701-type”) that incorporates cyanopropyl groups for enhanced polarity. Typical T_max ~280–290 °C. Excellent for solvents and polar analytes; corresponds to USP G46 and similar phases used for residual solvents analysis.
CR-17 – 50% phenyl, 50% methyl polysiloxane. A high-mid-polarity (polarizable) phase, equivalent to OV-17/DB-17 type columns. T_max ~300–320 °C. Provides strong aromatic and polar compound resolution for specialized uses (e.g., certain pesticides, phenols).
CR-624 – 6% cyanopropylphenyl, 94% methyl polysiloxane. A low/mid-polar phase optimized for volatile organic compounds (similar to “624” type columns, USP G43T_max ~260 °C. High affinity for purgeable halogenated solvents and residual solvents (USP <467>).
CR-Wax – Polyethylene glycol (PEG) phase (equivalent to Carbowax® 20M type). Polar phase for alcohols, glycols, and other polar volatiles. T_max ~250 °C. Provides strong hydrogen-bonding interactions.
CR-SE52 & CR-SE54 – Specialty 5% phenyl phases. CR-SE52 is another 5% phenyl 95% dimethyl polysiloxane (similar to CR-5 but legacy polymer type), and CR-SE54 is a 5% phenyl, 1% vinyl, 94% methyl polysiloxane variant. Both are low-polarity and share similar applications with CR-5 (T_max ~330–350 °C). They are included for method-matched needs where those specific phase designations (SE-52, SE-54) are required by legacy methods.

Technical Specifications

Feature	Specification & Notes
Column Type	Fused silica capillary with polyimide outer coating
Film Thickness Range	0.10 μm to 5.00 μm
Inner Diameter (ID)	0.10 mm to 0.53 mm
Length Options	10 m, 15 m, 30 m (standard), 60 m
Deactivation	Ultra-low bleed, silanol-free surface for universal compound compatibility
Crosslinking	Fully bonded stationary phase (resistant to solvent wash and thermal cycling)
Temperature Stability	Up to 350 °C (phase dependent)
Detectors Compatible	FID, ECD, TCD, MS
Quality Tests	USP phase identity, efficiency (plates/meter), peak symmetry, bleed performance
Regulatory Compliance	USP, Ph.Eur, EPA, ISO

All CR Standard columns are bonded (crosslinked) to the capillary wall, ensuring low bleed and solvent resistance. They are made from high-purity fused silica, coated with durable polyimide on the outside for flexibility. Available column dimensions cover a wide range to fit any GC method: inner diameters from 0.10 mm up to 0.53 mm, lengths from 10 m up to 60 m (with 30 m as a common standard), and film thicknesses from ultra-thin 0.1 µm for high-speed or high-temperature work up to 5.00 µm for high-capacity or volatile retention needs. Temperature limits vary by phase: e.g. CR-1 and CR-5 can typically be used up to ~340–350 °C, mid-polars like CR-1701 to ~280 °C, and Wax to ~250 °C. All columns undergo extensive deactivation during manufacturing to guarantee inertness for a broad range of compound classes. The bleed profile of CR Standard columns at their upper temperature limits is minimal and on par with industry benchmarks for general-purpose columns. They produce stable baselines even in temperature-programmed runs, ensuring compatibility with sensitive detectors (FID, ECD, TCD, etc. – and even GC/MS for general purposes). Each phase’s USP designation confirms its compliance with pharmacopeial inertness standards and phase ratios (e.g., CR-1 meets USP G1/G2/G38 specs for 100% dimethyl columns. Columns are quality-tested for efficiency (plates/meter) and peak symmetry using test mixes appropriate for each phase’s polarity.

Typical Applications

CR Standard GC columns excel in a wide array of applications, making them a go-to choice for analytical labs:

Environmental Analysis

Widely used in EPA methods for volatile and semivolatile organic pollutants.
For example, CR-624 columns are ideal for purge-and-trap VOCs in water (EPA 524.2, 624) and volatile aromatic hydrocarbons (BTEX), while CR-5 or CR-1701 columns handle semivolatiles (EPA 525.2, 8270) including pesticides, phenols, PAHs and PCBs. CR-17 (50% phenyl) can serve as a confirmation column for organochlorine pesticides (EPA 8081) or herbicides, offering alternate selectivity.

Petrochemical & Fuels

CR-1 non-polar columns are perfect for simulated distillation (SimDist) of crude oil fractions and fuels, as well as natural gas analysis (permanent gases and hydrocarbons) due to their inertness and high temperature tolerance.
The low bleed of CR-1 ensures stable baselines even up to C_40+ hydrocarbons.
CR-1 is also used in PONA (Paraffins, Olefins, Naphthenes, Aromatics) analysis in reformulated gasoline and detailed hydrocarbon analysis (DHA) where a completely non-polar separation is required.

Flavors & Fragrances / Essential Oils

CR-5 and CR-35 columns provide excellent separation of complex mixtures of terpenes, esters, and other aroma compounds found in essential oils and fragrance formulations.
Their phenyl content enhances resolution of isomers.
For example, a CR-35 (35% phenyl) can better resolve certain polar flavor compounds or allergens in fragrances that would co-elute on a 5% phenyl column.

Pharmaceuticals & Fine Chemicals

CR Standard columns (especially mid-polar types like CR-1701) are commonly used for residual solvent analysis in pharmaceuticals (USP <467> Residual Solvents – where G43 phase is specified) and for general purity tests. CR-1701 and CR-17 columns’ enhanced polarity also make them suitable for polar drug impurities, organics acids or bases (when derivatized), and phenolic compounds.
Meanwhile, CR-1 or CR-5 can be used for drug synthesis impurity profiling or checking solvent contamination.

Industrial Chemicals & Others

The broad applicability means CR Standard columns handle analyses like polychlorinated biphenyls (PCBs) in transformer oils, phenol and formaldehyde resin monomers, solvent purity testing (CR-1 is often chosen for trace solvent impurity assay due to its inertness), and more.
They are truly all-purpose – laboratories can often run diverse methods on a single CR-5 or CR-1 column without needing multiple specialized columns.

Performance Benefits

Scientific Precision with Commercial Persuasion

Feature	Benefit Description
High-Quality Deactivation	Ensures ultra-inert surfaces; minimizes peak tailing for active compounds (e.g., amines, phenols, organophosphates).
Low Column Bleed	Maintains stable baselines at high temperatures, even during gradient runs — ideal for sensitive detectors like FID and MS.
Fully Bonded Stationary Phases	Prevents phase loss and degradation; allows for solvent-rich injections and temperature cycling without compromising performance.
Sharp Peak Shapes	Enhanced resolution and sensitivity due to excellent efficiency and peak symmetry — especially useful in trace-level analysis.
Wide Phase Chemistry Selection	Enables tailored separations (from nonpolar to polar analytes) — labs can fine-tune resolution with the right CR phase (CR-1, CR-5, CR-1701, etc.).
Batch-to-Batch Reproducibility	Each lot tested for USP specs, efficiency, selectivity, and bleed performance — ensuring consistent results across production runs.
Broad Detector Compatibility	Suitable for use with all major GC detectors (FID, TCD, ECD, MS), providing flexibility across application types.
Regulatory Compliance	Aligns with USP, Ph.Eur, EPA, and ISO standards — simplifying audits, regulatory submissions, and method validations.
Commercial Advantage	CR Standard columns can directly replace popular brands (e.g., DB-1, DB-5, HP-5) with equal or superior performance — reducing inventory complexity and vendor cost.

Scientific precision with commercial persuasion.

CR Standard columns deliver consistent, reproducible separations with excellent peak shape due to high-quality deactivation (minimizing tailing even for active compounds). They feature low column bleed across their operating range, which preserves detector sensitivity and baseline stability. The fully bonded stationary phases prevent phase bleed or loss even under solvent-rich injections, giving long column life. Because of their robust inertness, analysts observe sharper peaks and higher responses for labile compounds (e.g. organophosphates, phenols) compared to economy-grade columns. The broad phase selection means users can optimize separations (choose a phase with just the right polarity) without compromising on column quality – a persuasive benefit for labs wanting the best results in one pass. Moreover, CR Standard columns are manufactured to rigorous quality specs (each batch tested for efficiency and selectivity), ensuring that column-to-column reproducibility is high – a critical factor for regulated labs. From a commercial perspective, the versatility of the Standard range reduces the need for multiple brands: Chrom Science & Technology’s CR columns can replace an array of competitor columns (e.g., DB-5, DB-1, etc.) with equal or better performance, simplifying inventory and vendor management. In summary, CR Standard columns combine proven stationary phases with modern manufacturing to offer reliability and performance that instills confidence in daily GC analyses.

Industry Compliance & Standards

The CR Standard range is designed to meet or exceed industry standards for general-purpose GC columns. They conform to USP and Ph. Eur. phase specifications (as noted above for each phase code), ensuring they can be directly used in pharmacopeial methods that call for those phase designations. For environmental methods, they are cross-referenced to EPA method requirements: e.g., CR-1 and CR-5 are referenced for EPA 502/8021 (purgeable aromatics) and EPA 525/8270 (semivolatiles); CR-624 meets EPA 624 for volatile purgeables; CR-1701 and CR-Wax meet criteria for specific method needs like alcohol or glycols analysis. Many CR Standard phases are equivalent to common US EPA and EU methods columns. (For instance, CR-624 is equivalent to USP G43 and matches columns specified in EPA Methods for volatile organics) Additionally, the columns follow ISO and ASTM guidelines where applicable – such as ASTM D Pharmacopoeia methods for essential oils, or ASTM D5375 for FAMEs if using a polar wax column. In summary, labs can confidently substitute a CR Standard column in any standard method calling for a similar phase, knowing it will meet the regulatory method performance criteria.