Sudden baseline interference or failed embryo culture batches are common risks in HPLC liquid chromatography systems. The root cause is often contamination of the solvent water with inorganic ions or organic impurities.

This directly destroys the accuracy of sensitive micro-measurements. Therefore, strict adherence to laboratory distilled water standards is a prerequisite.

This article provides an in-depth analysis of the technical parameters digitized according to national standards. We will explore modern ultrapure water filtration hardware solutions to standardize the analytical process.

1. Classification of Laboratory Water According to TCVN 4851

1.1 Details of the 3 Grades of Technical Analytical Water

The classification system for laboratory solvents is strictly standardized to ensure repeatability. Based on the legal technical document TCVN 4851:1989 (completely equivalent to the international standard ISO 3696), water used for analysis is divided into 3 types.

Type 1 water: Completely free of dissolved or colloidal contaminants, meeting the requirements for stringent trace concentration analysis.

Type 2 water: Contains very small amounts of inorganic or organic contaminants, suitable for measurements such as atomic absorption spectroscopy.

Type 3 water: Suitable for routine wet chemical analysis and basic instrument rinsing cycles.

1.2 Requirements for measuring electrical conductivity at the tap

Due to its high osmotic pressure, ultrapure Type 1 water tends to strongly absorb ions. Upon contact with air, this fluid rapidly absorbs CO2 to form carbonic acid (H2CO3). This physicochemical reaction rapidly increases the amount of free ions and causes a surge in electrical conductivity.
Therefore, the standard stipulates that we must measure the electrical resistance value online directly at the tap. Storing Type 1 water in conventional containers will result in a loss of its original purity. This sampling procedure is a mandatory technical hurdle to maintain data integrity.

Measuring the electrical resistance of distilled water used in laboratories

2. Type 1 and Type 3 Ultrapure Water Filtration Technology

2.1 RO Filtration Cycle Combined with Deionization (DI)

This modern laboratory water treatment method utilizes mechanical membrane filtration combined with ion exchange resin beads. The initial raw water passes through an RO reverse osmosis membrane to remove 95% – 98% of dissolved salts. Next, the fluid stream progresses through a Deionization (DI) resin column to remove narrow-band inorganic minerals.

To meet these stringent parameters, the Evo-CB DIO-VF 10 liters/hour Type 1 and Type 3 ultrapure water filtration system is the perfect solution. This high-end hardware ensures an output resistivity value of 18.2 MΩ·cm. This is the optimal equipment configuration for continuous ultrapure water treatment.

The Mirea ST water purifier, distributed by Duc Duong, meets the stringent requirements for distilled water used in laboratories

2.2 Intuitive DIO Digital Management Interface

All system operating parameters need to be continuously monitored to control sensor drift errors. Based on the digitized information axis from the official website of the manufacturer Mirae ST Korea, the device is equipped with an intelligent DIO interface. The digital display shows the conductivity and temperature values ​​in real time.

This mechanism helps Lab Managers easily create operating logs for quality auditing. When the ion exchange resin beads are saturated, the system will automatically issue a core replacement warning. The transparency of the data stream helps improve the management capacity of the laboratory.

3. Endotoxin and Microbiological Removal for Molecular Biology

3.1 Preventing the Harmful Effects of Endotoxins and Degrading Enzymes

Bacterial endotoxins and nucleases are harmful agents that disrupt the gene amplification reaction chain. Their presence at extremely low concentrations can completely disrupt cell analysis processes. Therefore, the narrow-band mechanical separation method of ultrafiltration (UF) membranes is applied.
Ultrafiltration membranes establish an effective molecular cutting range of ultra-small molecules below 5000 Daltons. This geometric structure retains all toxic pyrogens but allows pure water molecules to pass through. This ensures absolute biosafety for mycelial culture samples.

The Mirea ST model UF laboratory water filter ensures biosafety for mycelial culture samples

3.2 Configuration of High-End Integrated Ultrafiltration (UF) Membrane Filtration System

For the in-vitro fertilization and biomedical engineering segments, we need a synchronized system of specialized hardware. Currently, the Evo-Up DIO-VF TOC ultrapure water filtration system and the Evo-CB DIO-UF series supplied by Duc Duong fully meet this configuration. The equipment thoroughly removes suspended particles and pyrogens.

The output Type 1 water becomes an ideal sterile solvent for tissue culture chambers. This narrow-band hardware solution prevents the risk of cell contamination from the water source. This is a crucial technological investment for high-end biomedical research centers.
Your lab and quality management team are looking for a solution to equip a super-pure water filtration system integrating UF and UV membranes that meet the technical specifications of TCVN 4851. Please fill out the Contact Form at Duc Duong Company to receive the fastest support from our solution engineers.

4. Controlling Total Organic Carbon (TOC) for Chromatography

4.1 Consequences of Baseline Interference Due to Organic Impurities

High levels of total organic carbon (TOC) in water solvents will destroy the performance of chromatographic detectors. Organic impurities adhere to the stationary phase of the separation column, generating harmful spurious peaks. At the same time, this mechanical error increases baseline interference and reduces analytical sensitivity.
Therefore, QC technicians need to maintain a narrow-band TOC index at <= 5 ppb. Strict control of organic impurity concentration is a vital criterion for HPLC liquid chromatography. This factor determines the integrity and reliability of the entire raw data stream.
4.2 Dual-Wavelength UV Lamp Technology for Carbon Bond Destruction
To break down the structure of trace organic compounds, we need to apply high-band optical radiation. The optimal solution is to equip the chromatography system with a 10 liters/hour Evo-CB DIO-UV ultra-pure water filtration system (Type 1 and Type 3). The device integrates dual-wavelength UV lamp technology emitting simultaneously at 185nm and 254nm.
The 185nm ultraviolet light activates a reaction that generates strong oxidizing hydroxyl radicals (OH). These free radicals decompose the carbon bonds of organic compounds and bring the TOC range to extremely low levels. The closed photochemical cycle ensures that the Type 1 water solvent always achieves high spectral purity.

5. Risks of Water Quality Degradation and Storage Rules

5.1 Degradation Kinetics of Type 1 Water

Ultrapure Type 1 water, after being discharged from the tap, faces very rapid degradation kinetics. Due to its absolute resistance of 18.2 MΩ·cm, this fluid is highly ionic from the lab air environment. The water absorbs free carbon dioxide (CO2) to form carbonic acid, causing a mechanical degradation.
In addition, storing Type 1 water in sticky plastic containers poses a risk of plasticizer leaching. After only a short narrow-band period, clean solvents will be downgraded to Type 2 or Type 3. Therefore, quality control professionals must strictly prohibit the storage of Type 1 water.

5.2 SOP Direct Discharge and Vent Filter Setup for Type 3 Tanks

The standard operating procedure (SOP) stipulates that Type 1 water must be discharged directly from the tap. You are not allowed to use Type 1 water that has been stored overnight for microchromatographic analyses. For typical Type 3 water, we can store it in dedicated tanks.

However, Type 3 tanks must be equipped with a vent filter assembly with a carbon adsorption membrane filter structure. This accessory prevents condensation droplets, bacteria, and toxic gases from entering the clean fluid stream. This practical SOP operation ensures homogeneity and narrow-band cleanliness for the entire laboratory.

6. Maintenance Cycle and Consumable Costs of the Filtration System

6.1 Schedule for Replacing Consumables

To ensure the stability of the system’s measurement range, establishing a schedule for replacing worn components is mandatory. The frequency of hardware maintenance is specifically recommended by experts based on operating time. This periodic replacement process prevents risks of degradation of baseline water quality in the sloping range.
Coarse filter and activated carbon column: Replace periodically every 6 months to remove excess chlorine.
Deionization (DI) ion exchange resin column: Replace after 12 months or when the impedance drops below 10 MΩ·cm.
Dual-wavelength UV lamp and UF ultrafiltration membrane: Replace after 24 months of continuous operation.

6.2 Duc Duong’s ISO 17025 Standard After-Sales Service

Duc Duong Company provides comprehensive maintenance solutions certified to ISO 17025 measurement standards. We are committed to distributing genuine Mirae ST equipment from Korea with complete CO/CQ certification documents. Our team of experienced engineers provides support and guidance on operating the laboratory according to standard SOPs for businesses.

At the same time, we provide a package for checking the error of the conductivity probes integrated into the filtration machine. This synchronization ensures that the water quality management cycle of the factory always operates continuously and stably. Factory managers and procurement departments can rest assured about the availability of spare parts and components.

Conclusion

In summary, the application of an automatic ultrapure water filtration solution plays a crucial role in controlling the quality of laboratory solvents. Businesses need to strictly comply with the national standard TCVN 4851 for water classification, integrate wideband UF ultrafiltration membrane technology and dual-wavelength UV lamps to effectively eliminate TOC/Endotoxin levels, and apply a direct flushing system.

Duc Duong Science and Technology Company is proud to be the official distributor of Mirae ST ultrapure water purifiers from Korea, ready to provide technical support and supply complete materials to help laboratories optimize the integrity of measurement data.

To receive a complete technical specifications catalog and optimal price list for the Evo DIO ultrapure water purifier configurations (Type 1 and Type 3) meeting ISO 3696 standards, please fill out the information at Duc Duong Company Contact or contact our analytical equipment project department for the most comprehensive support.

 

DUC DUONG SCIENCE AND TECHNOLOGY COMPANY

Address: 1014/67 Tan Ky Tan Quy, Binh Hung Hoa Ward, Binh Tan District, Ho Chi Minh City

Tel: (028) 3762 8042 – 3762 8043 – 3750 8514 – 3750 8793

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Email: ducduong@ducduongco.com

Website: ducduongco.com

ZALO OA: DUC DUONG SCI

 

FAQ

1. What are the core differences in resistivity and conductivity between Type 1 and Type 3 water according to TCVN 4851?

Based on the legal technical document TCVN 4851:1989, Type 3 water used for general analysis allows a maximum conductivity of 5.0 mS/cm at 25°C. Meanwhile, ultra-pure Type 1 water strictly requires a conductivity not to exceed 0.1 mS/cm. This is equivalent to an ideal resistivity value of 18.2 MOmega.cm, proving that the water source is completely free of dissolved inorganic mineral ions.

2. Why is a total organic carbon (TOC) level below 5 ppb a critical criterion for HPLC detectors?

High-band total organic carbon (TOC) represents polymer impurities or microbial debris remaining in the water solvent. When running high-performance liquid chromatography (HPLC), these organic substances adhere to the stationary phase of the separation column, denaturing the effective spectral retention ability, generating ghost peaks on the chromatogram, and increasing baseline noise. Controlling the TOC range to <= 5 ppb using dual-wavelength UV lamp technology ensures the integrity of trace analysis data.

3. What mechanical principle does the Ultrafiltration (UF) membrane integrated into the Evo DIO system use to remove endotoxins?

Bacterial endotoxins (endotoxin/pyrogen) and degrading enzymes (RNase, DNase) possess macromolecular polymer chain structures with a broad molecular weight gradient. The Ultrafiltration (UF) membrane integrated into the ultrapure water purification systems of Mirae ST Korea operates on a narrow-band mechanical sieving mechanism with an effective molecular shear limit below 5000 Daltons. This membrane structure allows pure water molecules to pass through while completely retaining biological toxins on the membrane surface, providing sterile water that meets standards for cell labs and IVF (in vitro fertilization).

4. Why does TCVN 4851 standard prohibit establishing a pH limit range for Type 1 ultrapure water?

Type 1 ultrapure water possesses absolute ionic purity, so it has absolutely no pH buffering capacity (the ability to resist changes in H+ ion concentration). Upon contact with the electrode of a conventional pH meter, Type 1 water will rapidly absorb a small amount of CO2 gas from the air to convert into H+ and HCO3- ions, causing a false drop in pH and a shock to the digital display data. Therefore, TCVN 4851 standard stipulates that pH measurement should not be performed on Type 1 water, but instead, it should be completely replaced by controlling the electrical resistance parameter of 18.2 MΩ·cm.

5. What technical criteria should be considered during the maintenance and replacement process of the Deionization DI ion exchange column in a water purifier?

The Deionization (DI) ion exchange resin column is responsible for separating dissolved mineral cations and anions through the exchange mechanism of free chemical functional groups. When the ion exchange resin beads become saturated with energy, the resistance displayed on the DIO screen will tend to drop rapidly from 18.2 MΩ·cm to below the control limit of 10 MΩ·cm. At this point, the Lab Manager must establish a SOP to replace the DI column to prevent reverse ionic leaching errors in the fluid, ensuring that the laboratory’s quality management process operates continuously and stably in accordance with ISO 17025 standards.