Specification of

Details

The HI94754B-25 COD kit contains 25 ready-to-use, barcoded vials containing pre-measured reagents. These high quality reagents follow the EPA approved method 410.4. In this method, a heated digestion is required to oxidize organic matter in the sample. During the digestion, hexavalent chromium in the reagent is reduced to trivalent chromium. The amount of reduced chromium is then measured colorimetrically. The intensity of color is determined by a compatible photometer and the COD concentration is displayed in mg/L (ppm) O2. These reagents are designed to be used with samples that have an expected range of 0 to 1500 mg/L (ppm) O2.

Automatic recognition of barcoded samples is an exciting feature when using the HI94754B-25 reagent vials with a barcode compatible photometer. When inserted into the vial holder of the photometer, the sample method and range are automatically identified from the barcode. The barcode has four digits: the first two digits are for parameter identification and the second two digits are for reagent lot ID. Vials for different COD methods can be distinguished by a barcode printed on the vial - the barcodes for different methods are shown in the table below.

Comparison of Methods

Method	Parameter	Range (as O2)	Resolution	Accuracy	Reagent Code
EPA	COD LR	0 to 150 mg/L	1 mg/L	±5 mg/L ±5% of reading	HI94754A-25
EPA	COD MR	0 to 1500 mg/L	1 mg/L	±15 mg/L ±4% of reading	HI94754B-25
Dichromate	COD HR	0 to 15000 mg/L	10 mg/L	±150 mg/L ±3% of reading	HI94754C-25
Mercury-free	COD LR	0 to 150 mg/L	1 mg/L	±5 mg/L ±5% of reading	HI94754D-25
Mercury-free	COD MR	0 to 1500 mg/L	1 mg/L	±15 mg/L ±4% of reading	HI94754E-25
ISO	COD LR	0 to 150 mg/L	1 mg/L	±5 mg/L ±5% of reading	HI94754F-25
ISO	COD MR	0 to 1500 mg/L	1 mg/L	±15 mg/L ±4% of reading	HI94754G-25