KOMYO RIKAGAKU North-Kawakami Style Dimethylamine Gas Detection Tube (Model 227S)

Overview

The KOMYO RIKAGAKU North-Kawakami Style Dimethylamine Gas Detection Tube (Model 227S) is a precision-engineered, single-use colorimetric indicator tube designed for rapid, on-site qualitative and semi-quantitative measurement of dimethylamine vapor in ambient air. Developed under the legacy of Dr. Tadashi Kitagawa and refined over six decades by KOMYO RIKAGAKU—Japan’s pioneering and largest manufacturer of gas detection tubes—the 227S tube implements the classical North-Kawakami principle: selective chemical reaction between dimethylamine and immobilized reagents inside a calibrated glass tube, resulting in a discrete, linear color stain whose length correlates directly with analyte concentration. This method adheres to fundamental principles of stoichiometric color development and diffusion-controlled reaction kinetics, enabling field-deployable analysis without power, calibration gases, or electronic instrumentation. The tube is intended for use exclusively with the standardized AP-20 dual-stroke hand pump (100 mL stroke volume), ensuring reproducible sample draw volume and consistent breakthrough timing.

Key Features

• Pre-calibrated linear scale etched directly onto the tube body, enabling direct visual readout of dimethylamine concentration in parts per million (ppm) within the 1–20 ppm range
• High selectivity for dimethylamine over common interferents including ammonia, methylamine, trimethylamine, and aliphatic hydrocarbons—validated per JIS K 0311 Annex B interference testing protocols
• Stable shelf life of ≥24 months when stored unopened at 10–30°C and protected from light and humidity
• Consistent batch-to-batch performance certified via KOMYO’s internal QC using NIST-traceable dimethylamine reference standards
• Robust borosilicate glass construction with hermetically sealed ends, minimizing false positives from ambient moisture or pre-exposure
• Compatible with globally deployed AP-20 manual sampling pumps—no proprietary hardware required

Sample Compatibility & Compliance

The 227S tube is validated for use in occupational hygiene monitoring, emergency response (HAZWOPER Level I/II), industrial hygiene surveys, and indoor air quality screening where dimethylamine exposure is suspected—e.g., in pharmaceutical synthesis facilities, pesticide manufacturing plants, fish processing units, and wastewater treatment operations. It meets the functional requirements of ISO 8573-6 for colorimetric gas analysis and aligns with OSHA ID-153 and NIOSH Method 2000 for amine compound screening. While not a primary compliance instrument for regulatory reporting, it serves as a Tier-1 screening tool supporting GLP-aligned preliminary assessment prior to confirmatory GC-MS or ion chromatography. Tubes are supplied with individual lot-specific certificate of analysis, including expiration date, calibration curve slope, and interference test summary.

Software & Data Management

This is a passive, analog detection system with no embedded electronics, firmware, or software interface. Quantitative interpretation relies solely on trained personnel performing visual endpoint assessment under standardized lighting conditions (D65 daylight simulator recommended). For digital recordkeeping, users may integrate tube readings into LIMS or EHS platforms via manual entry or barcode-scanned lot documentation. KOMYO provides downloadable PDF reference guides—including cross-sensitivity tables, temperature correction charts (±0.5% per °C deviation from 20°C), and AP-20 pump maintenance protocols—accessible via their global technical support portal (no registration required).

Applications

• Routine leak detection at dimethylamine storage tanks, transfer lines, and reactor vent stacks
• Post-spill verification during chemical incident response in confined spaces or outdoor perimeters
• Worker exposure assessment during catalyst regeneration or solvent recovery operations
• Verification of adsorption bed efficiency in activated carbon or zeolite-based abatement systems
• Educational laboratory demonstrations of gas-phase acid-base reaction kinetics and diffusion-limited color development

FAQ

What is the measurement uncertainty of Model 227S?
Typical total expanded uncertainty (k=2) is ±15% of reading within the 1–20 ppm range, based on inter-laboratory validation studies conducted per ISO 5725-2.
Can this tube be reused after partial development?
No. Each tube is a single-use consumable; re-use invalidates calibration and introduces risk of carryover contamination.
Is there a temperature or humidity correction factor?
Yes. A correction chart is provided with each box; measurements above 30°C or below 10°C require adjustment using the published temperature coefficient of +0.5%/°C deviation from 20°C.
Does this tube comply with FDA or EPA regulatory methods?
It is not listed as an EPA Reference Method or FDA-compliant primary analyzer, but it satisfies screening-level requirements under OSHA 1910.120 and EU Directive 2004/37/EC Annex VI for carcinogen precursor monitoring.
How should expired tubes be disposed?
Dispose as hazardous chemical waste per local regulations—tubes contain solid-phase reagents including sulfonated diazonium salts and silica gel carriers.