Hach DR2400 Manual page 356

Lead
Apparatus and Sample Preparation
Sample Collection, Storage and Preservation
Lead
Page 4 of 8
The Extractor plunger may be reused for more than one test but should be rinsed
between uses.
Interfering Substance
3+
Aluminum, Al
+
Ammonium, NH
4
Barium, Ba 2+
Calcium, Ca 2+
Chloride, Cl –
Copper, Cu 2+
Fluoride, F –
2+
Iron, Fe
2+
Magnesium, Mg
2+
Manganese, Mn
–
Nitrate, NO
3
2–
Sulfate, SO
4
2+
Zinc, Zn
Because lead is very common to our environment, care must be taken to prevent
sample contamination. Follow these steps for greatest test accuracy:
• Lead-free water is necessary to minimize sample contamination when
rinsing apparatus or diluting sample. The water may be either distilled or
deionized. If the water is obtained from a grocery store, verify the lead
concentration is zero from the label. If the lead concentration is uncertain,
determine the lead concentration with the LeadTrak test.
• Plastic or glass sample containers and lids may be checked for contamination
by rinsing with 1 mL of pPb-1 Acid Preservative Reagent (Cat. No. 23685-31).
Add 100 mL of lead-free water. After 24 hours, analyze this solution using
the LeadTrak test to confirm the absence of lead.
• Rinse glassware used in this test with a small amount of dilute lead-free
0.1 N nitric acid or pPb-1 Acid Preservative Reagent followed by rinsing
with lead-free water.
• pPb-5 Indicator may be rinsed from the glass sample cells with a few drops
of pPb-1 Acid Preservative Reagent or a small amount of dilute lead-free
nitric acid.
• Acidify solutions containing lead with Nitric Acid (Cat. No. 152-49) or pPb-1
to below pH 2 to prevent adsorption of lead onto the container walls. See
Sample Collection, Storage and Preservation.
Samples may be collected either from household pipes (point-of-use) or from
water sources. Preserved samples may be stored up to six months. Each sample
type typically requires different sampling procedures. Consult with the
appropriate regulatory agency in your area for more information about your
specific sampling requirements.
Interference Levels and Treatments
0.5 mg/L
500 mg/L
6 mg/L
500 mg/L
1000 mg/L
2 mg/L
10 mg/L
2 mg/L
500 mg/L
05 mg/L
1000 mg/L
1000 mg/L
1 mg/L
Lead_None_Other_LTK_Eng_Ody.fm