DR/2400
Chromium, Total
ChromiumTot_UniCell_Other_DCH_Eng_Ody.fm Page 1 of 4
• Adjust pH of preserved samples to between pH 3–9 before analysis.
• Clean the outside of the vial before placing it in the instrument. Wipe with a damp towel, followed by a dry one.
• Use the standard solution or standard addition method to verify results. See Accuracy Check.
• See Section 3.2.4 in the procedure manual for information on adjusting the calibration curve.
• Make sure that the temperature of the water sample and the sample vial is between 15–25 °C.
• Underrange appears on the display when the instrument is zeroed or when the determined sample concentration is below the
operating range listed for this method.
Chromium, Total
1,5-Diphenylcarbohydrazide Method
UniCell™ Vials
(0.03 to 1.00 mg/L Tot-Cr)
Scope and Application: For water and wastewater
1. Touch
Hach Programs.
Select program
803 Chromium, HCT 156
Touch Start.
2. Pipet 4.0 mL of
sample into a sample
vial.
3. Screw a blue
UniCap A (HCT 156 A)
onto the sample vial.
4. Invert the sample vial
several times to mix.
Tips and Techniques
UniCell Vials
Hach Programs