Nitrogen Standards, ISA & Buffers


In water and wastewater testing, nitrogen standards, ionic strength adjusters (ISAs), and buffers serve critical but distinct functions for accurate analysis. Nitrogen standards provide known concentrations for calibrating instruments like spectrophotometers and ion-selective electrodes (ISEs) to quantify ammonia, nitrate, nitrite, and total nitrogen, establishing baselines for assessing water quality and treatment efficiency. ISAs equalize ionic strength between standards and samples when using ISEs, which measure ion activity rather than true concentration; by maintaining constant activity coefficients, ISAs ensure measured signals directly correlate with target ion concentrations, improving accuracy in complex matrices like wastewater. Buffers maintain stable pH during analytical procedures, which is essential because many chemical reactions and enzyme activities are pH-sensitive; they calibrate pH meters with precisely known pH values and optimize wastewater treatment processes by controlling influent pH to enhance biological activity, prevent corrosion, and improve chemical treatments like coagulation and disinfection.

Core & Main Ammonia Standard, 1.0 ppm as N, 1 L
$41.30

Mfr. Part # AS1001-Q

Product # 707324

Core & Main Ammonia Standard, 1.0 ppm as N, 500 mL
$28.95

Mfr. Part # AS1001-P

Product # 707323

Core & Main Nitrate Standard as N, 1000 mg/L (ppm), 1 L
$54.35

Mfr. Part # NS4750-Q

Product # 707112

Core & Main Nitrate Standard as N, 1000 mg/L (ppm), 500 mL
$33.15

Mfr. Part # NS4750-P

Product # 707111

Core & Main Nitrate Standard as N, 100 mg/L (ppm), 1 L
$54.35

Mfr. Part # NS4700-Q

Product # 707110

Core & Main Nitrate Standard as N, 100 mg/L (ppm), 500 mL
$33.05

Mfr. Part # NS4700-P

Product # 707109

Core & Main Nitrate Standard as N, 10.0 mg/L (ppm), 1 L
$59.05

Mfr. Part # NS4610-Q

Product # 707108

Core & Main Nitrate Standard as N, 10.0 mg/L (ppm), 500 mL
$32.20

Mfr. Part # NS4610-P

Product # 707107

Core & Main Nitrate Standard as N, 2.0 mg/L, 1 L
$51.40

Mfr. Part # NS4602-Q

Product # 707106

Core & Main Nitrate Standard as N, 2.0 mg/L, 500 mL
$31.15

Mfr. Part # NS4602-P

Product # 707105

Core & Main Nitrate Standard as N, 1.0 mg/L (ppm), 1 L
$53.70

Mfr. Part # NS4601-Q

Product # 707104

Core & Main Nitrate Standard as N, 1.0 mg/L (ppm), 500 mL
$41.25

Mfr. Part # NS4601-P

Product # 707103

Core & Main Ammonia Standard, 100ppm as N, 1 L
$55.65

Mfr. Part # AS1100-Q

Product # 706922

Core & Main Ammonia Standard, 100ppm as N, 500 mL
$34.25

Mfr. Part # AS1100-P

Product # 706921

Core & Main Ammonia Standard, 50ppm as N, 1 L
$68.80

Mfr. Part # AS1050-Q

Product # 706920

Core & Main Ammonia Standard, 50ppm as N, 500 mL
$34.00

Mfr. Part # AS1050-P

Product # 706919

Core & Main Ammonia Standard, 30ppm as N, 1 L
$50.95

Mfr. Part # AS1030-Q

Product # 706918

Core & Main Ammonia Standard Solution, 30 ppm as N, 500 mL
$34.00

Mfr. Part # AS1030-P

Product # 706917

Core & Main Ammonia Standard, 20ppm as N, 1 L
$50.95

Mfr. Part # AS1020-Q

Product # 706916

Core & Main Ammonia Standard, 20ppm as N, 500 mL
$34.00

Mfr. Part # AS1020-P

Product # 706915

Core & Main Ammonia Standard, 10ppm as N, 1 L
$41.30

Mfr. Part # AS1010-Q

Product # 706914

Core & Main Ammonia Standard Solution, 10 ppm as N, 500 mL
$28.95

Mfr. Part # AS1010-P

Product # 706913

Core & Main Ammonia Standard, 5ppm as N, 1 L
$74.60

Mfr. Part # AS1005-Q

Product # 706912

Core & Main Ammonia Standard, 5ppm as N, 500 mL
$34.00

Mfr. Part # AS1005-P

Product # 706911

Core & Main Ammonia Standard, 3ppm as N, 1 L
$62.95

Mfr. Part # AS1003-Q

Product # 706910

Core & Main Ammonia Standard, 3ppm as N, 500 mL
$34.00

Mfr. Part # AS1003-P

Product # 706909

Core & Main Ammonia Standard, 2ppm as N, 1 L
$66.35

Mfr. Part # AS1002-Q

Product # 706908

Core & Main Ammonia Standard, 2ppm as N, 500 mL
$34.00

Mfr. Part # AS1002-P

Product # 706907

Core & Main Ammonia Standard, 1000ppm as N, 1 L
$64.70

Mfr. Part # AS1000-Q

Product # 706906

Core & Main Ammonia Standard, 1000ppm as N, 500 mL
$42.25

Mfr. Part # AS1000-P

Product # 706905

Core & Main Ammonia Standard, 0.2 ppm as N, 1 L
$55.70

Mfr. Part # AS1202-Q

Product # 706904

Core & Main Ammonia Standard, 0.2 ppm as N, 500 mL
$34.00

Mfr. Part # AS1202-P

Product # 706903

Hach Borate Buffer Solution, 1 L, 1470953
$66.19

Mfr. Part # 1470953

Product # 701049

Hach Nitrate Ionic Strength Adjustor (ISA) Buffer Solution, 500 mL, 2488349
$57.45

Mfr. Part # 2488349

Product # 701632

Hach Nitrate Ionic Strength Adjustor (ISA) Powder Pillows, pk/100, 4456369
$90.95

Mfr. Part # 4456369

Product # 702088

Hach Ammonium Ionic Strength Adjustor (ISA) Powder Pillows, pk/100, 2980699
$92.99

Mfr. Part # 2980699

Product # 702042

Hach Ammonia Ionic Strength Adjustor (ISA) Powder Pillows, pk/100, 4447169
$49.19

Mfr. Part # 4447169

Product # 702082

Hach Nitrate Ionic Strength Adjustor Powder Pillows, Pack of 100, 2984799
$90.95

Mfr. Part # 2984799

Product # 702043

Hach Ammonia Ionic Strength Adjustor (ISA), Solution, 500 mL, 2824349
$46.30

Mfr. Part # 2824349

Product # 701950

Hach Nitrate Standard Solution, 1000 mg/L, 500 mL, 1279249
$49.70

Mfr. Part # 1279249

Product # 700931

Hach Nitrite Standard Solution, Stock, 250 mg/L as N, 500 mL, 2340249
$59.09

Mfr. Part # 2340249

Product # 701451

Hach Ammonia Standard Solution, 100 mg/L as NH3-N, 500 mL, 2406549
$40.49

Mfr. Part # 2406549

Product # 701523

Hach Ammonia Standard Solution, 1000 mg/L as NH3-N, 1 L, 2354153
$40.89

Mfr. Part # 2354153

Product # 701481

Hach Nitrate Standard Solution, 1 mg/L, 500 mL, 204649
$41.15

Mfr. Part # 204649

Product # 700825

Hach Nitrate Standard Solution, 100 mg/L, 500 mL, 194749
$39.35

Mfr. Part # 194749

Product # 700807

Hach Ammonia Standard Solution, 1 mg/L as NH3-N, 500 mL, 189149
$41.15

Mfr. Part # 189149

Product # 700796

Hach Nitrate Standard Solution, 10 mg/L as NO3-N (NIST), 500 mL, 30749
$33.35

Mfr. Part # 30749

Product # 700618

Hach Ammonia Standard Solution, 10 mg/L as NH3-N, 500 mL, 15349
$41.15

Mfr. Part # 15349

Product # 700567