ST-COD - ISO 15705, HJ/T399-2007 Sealed Tube Test Kit Method

ST-COD according to ISO

The methods of 15705/EPA 410.4 and HJ/T399-2007 use the same reaction as the sealed tube reagent kit method, and are detected by photometry instead of traditional titration. The ST-COD method uses pre made reagent kit sealed tubes, which have the advantages of being more environmentally friendly, safe, and minimizing the use of hazardous reagents.

The SP2000 ST-COD analyzer includes an XYZ sample processing system with detachable sample tubes and test tube racks, making it easy to prepare and add samples that require additional measurements. The analyzer consists of a robotic arm and two manipulators, one manipulator is equipped with a pneumatic fixture, and the other is equipped with a sample needle and stirrer.

The analyzer also includes a sealed tube opening/closing device, with a vertically vibrating vibrator for easy dissolution of solid reagents and sample mixing in the reagent kit, and a rotating oscillator for mixing the sealed tube sample before measurement. The instrument is equipped with two adjustable temperature constant temperature reactors.

The photometer reads the absorbance value and transmits the result to RoboticAccess ™ Used in software for data processing and quality control. The ST-COD reagent kit method can be easily extended for testing other indicators such as total phosphorus, total nitrogen, ammonia nitrogen, and other photometric methods.

Chemical Oxygen Demand (COD) is a universal method for indirectly measuring the organic content in water, and the value of COD is an important parameter for evaluating water quality. Skalar's SP2000 analyzer can be used for automatic COD measurement using either the sealed tube kit method according to ISO 15705/EPA 410.4 and HJ/T399-2007, or the classical titration method according to ISO 6060.Typical Sealed Tube - COD Automatic Analysis

Cheng

Load the sealed tube onto the testing rack and place it on the analyzer. The analyzer will lift the sealed tube and unscrew the bottle cap to automatically quantitatively transfer the sample to the sealed tube. Automatically tighten the sealing tube cover and transfer it to the vertical oscillator. After oscillating and mixing the sealed tube, transfer it to a heating reactor and heat it at 150 ° C for 2 hours. The instrument continuously records the reaction time. When the reaction time is reached, the instrument automatically places a sealed tube on the sample holder and cools it to 60 ° C, while still maintaining insulation and mixing. When the sample is cooled to room temperature, it is shaken and mixed before being transferred to a photometer for measurement at a specific wavelength. The concentration value of the sample is displayed on the computer screen and transmitted to the software and LIMS system.

Automatic steps:●

Lift the sealing tube●

Unscrew the sealing tube cover●

Transfer the sample to the sealed tube and tighten the lid●

Sample and reagent mixing●

Place the sealed tube on the heating reactor●

The sample is heated and reacted at 150 ° C for 2 hours●

Transfer the sample to the cooling bracket for cooling●

Sample oscillation mixing●

Measure COD concentration on a photometer●

Return the sample tube to the sample rack