Match seawater nitrite to the right chemistry and range
Use a seawater-specific, matched vial-and-powder method for 0–600 µg/L nitrite-nitrogen as NO₂-N. The pre-dosed format keeps preparation focused on the measured sample and the specified reagent addition, without heated digestion.
Factory photograph of the matched reagent format; packaging is illustrative, not a physical contents count.
Select the right method
Choose this set for seawater samples within the documented matrix limits and a nitrite-nitrogen range of 0–600 µg/L. It is not the HI764 marine ultra-low-range Checker refill, a nitrate test or a generic freshwater nitrite reagent.
A matched vial-and-powder workflow
The method combines HI96789V-0 Nitrite in Seawater reagent vial with HI96789-0 reagent powder. The prepared vial avoids making the acidic reagent mixture from bulk chemicals, while the matching packet supplies the color-development addition. The kit is specified for 25 nominal tests; the current US description does not separately itemize the physical packet count.
Zero and read the same sample vial
Add 10 mL sample to the reagent vial, cap and invert several times. Zero this sample-filled vial, then add one HI96789-0 packet and shake gently for 90 seconds. Allow 15 minutes for color development and read using the named instrument method. No heated reactor or digestion step is specified. Follow the full manual and the instructions for the supplied lot.
Keep nitrogen and nitrite mass distinct
The primary 0–600 µg/L range is as NO₂-N: nitrogen in nitrite. It equals 0–0.600 mg/L as N, not 0–600 µg/L as nitrite ion. The instrument’s chemical-form conversion changes the numerical reporting basis; do not relabel the same number as NO₂⁻ mass.
Check the seawater matrix before selecting
The manuals report testing with synthetic seawater ASTM D665 and identify chloride above 24000 mg/L as an interference. Other listed limits include sodium above 10000 mg/L, sulfate above 3000 mg/L and magnesium above 2500 mg/L. Seawater labeling does not mean every concentrated brine is suitable; review the complete interference table.
Provide the optical setup, not a heater
Use the HI83314 or HI83399 Nitrite Seawater vial method with the adapter specified by that instrument, accurate 10 mL sample transfer, timing and clean vial surfaces. The US format name and instrument method headings use different diameter conventions; compatibility here is based on the named procedures, not an asserted physical diameter. Instruments and preparation accessories are separate. Store unused vials in their packaging in a cool, dark place.
Compatibility and responsible handling
The named vial procedures are documented for HI83314 and HI83399. Use the method and adapter specified for your instrument. Review every matching component SDS and your actual lot instructions. Photometer, accessories and handling equipment are separate.
Frequently Asked Questions
Why choose this instead of an ordinary nitrite reagent?
It is the documented seawater vial-and-powder method, with matrix-specific interference limits. Select by your required matrix, range and instrument method rather than assuming interchangeability with freshwater kits.
Does 600 µg/L mean nitrite ion mass?
No. The primary range is 0–600 µg/L as NO₂-N, equivalent to 0–0.600 mg/L as nitrogen. Nitrite-ion mass requires a conversion and does not retain the same number.
Is this a refill for the HI764 marine ULR Checker?
No. This is HI96789-25 for the documented seawater vial methods, not HI764-25. The instruments, ranges and reagent formats are different.
How many tests are available after zeroing?
25 nominal tests. The sample-filled vial is zeroed before powder addition, so no extra sacrificial blank vial is deducted. QC and repeats consume reagents.
Is adding sample the only preparation step?
No. Add 10 mL sample and zero the vial, then add one HI96789-0 powder packet, shake gently for 90 seconds and allow 15 minutes of development before reading.
Do I need a heated reactor?
No. The direct seawater nitrite procedure specifies mixing and 15-minute color development, not heated digestion.
Which instruments and vial adapter are supported?
HI83314 and HI83399 directly document HI96789-25. Select their Nitrite Seawater vial method and the adapter specified in the instrument manual; no physical diameter or unverified SKU alias is inferred here.
Can I use it for concentrated brine?
Not without checking the full matrix limits. Chloride above 24000 mg/L can interfere, along with other ions listed in the manuals. The documented test matrix is synthetic seawater ASTM D665.
