Water sampling and analysis - Arsenic - Revision history

Gap: Protected "Water sampling and analysis - Arsenic" ([Edit=Allow only administrators] (indefinite) [Move=Allow only administrators] (indefinite))

2018-05-10T11:04:44Z

Protected "Water sampling and analysis - Arsenic" ([Edit=Allow only administrators] (indefinite) [Move=Allow only administrators] (indefinite))

Gap: /* References */

‎References

Gap at 08:36, 10 August 2026

Gap: Protected "Water sampling and analysis - Arsenic" ([Edit=Allow only administrators] (indefinite) [Move=Allow only administrators] (indefinite))

Protected "Water sampling and analysis - Arsenic" ([Edit=Allow only administrators] (indefinite) [Move=Allow only administrators] (indefinite))

Gap at 08:36, 10 August 2026

Gap: /* 0Arsenic analysis in the laboratory= */

‎0Arsenic analysis in the laboratory=

Gap at 08:36, 10 August 2026

← Older revision		Revision as of 08:36, 10 August 2026
Line 42:		Line 42:
	==References==		==References==
	For references, please visit the page [[References - Geogenic Contamination Handbook]].		For references, please visit the page [[References - Geogenic Contamination Handbook]].
		+
		+	==Related articles on GAP Wiki==
		+	*[[Water sampling and analysis ]]
		+	*[[Water sampling and analysis - Fluoride]]
		+	*[[Detailed water analyses]]

← Older revision		Revision as of 08:36, 10 August 2026
Line 1:		Line 1:
		+	''NOTE: Article from the Geogenic Contamination Handbook''
		+
		+
	Inorganic arsenic in groundwater is found in two different oxidation states: As(III) (arsenite) and As(V) (arsenate). There are also organic forms, but these are rare in drinking water. Both As(III) and As(V) are toxic, but the two species behave somewhat differently in the environment. The testing methods described in this manual give total inorganic arsenic concentrations, which are adequate for most general purposes. Specialised techniques are needed to tell whether arsenic is present as arsenite or arsenate. The detection range of interest is 10 to 50 µg/L (the typical range of national standards for arsenic). Maximum concentrations of naturally occurring arsenic in groundwater can exceed 1000 µg/L.		Inorganic arsenic in groundwater is found in two different oxidation states: As(III) (arsenite) and As(V) (arsenate). There are also organic forms, but these are rare in drinking water. Both As(III) and As(V) are toxic, but the two species behave somewhat differently in the environment. The testing methods described in this manual give total inorganic arsenic concentrations, which are adequate for most general purposes. Specialised techniques are needed to tell whether arsenic is present as arsenite or arsenate. The detection range of interest is 10 to 50 µg/L (the typical range of national standards for arsenic). Maximum concentrations of naturally occurring arsenic in groundwater can exceed 1000 µg/L.
	<br><br>		<br><br>

← Older revision		Revision as of 08:36, 10 August 2026
Line 35:		Line 35:

	UNICEF also supported the development of locally manufactured arsenic test kits in China, Thailand and Vietnam, and in China and Thailand, they are still in use. The Thai kit, developed and marketed by Mahidol University, has a detection range of 5–500 µg/L and is used in Thailand and in other countries in the region.		UNICEF also supported the development of locally manufactured arsenic test kits in China, Thailand and Vietnam, and in China and Thailand, they are still in use. The Thai kit, developed and marketed by Mahidol University, has a detection range of 5–500 µg/L and is used in Thailand and in other countries in the region.
		+
		+
		+	==References==
		+	For references, please visit the page [[References - Geogenic Contamination Handbook]].

← Older revision		Revision as of 08:36, 10 August 2026
Line 22:		Line 22:


−	=~~0Arsenic~~ analysis in the laboratory==	+	==Arsenic analysis in the laboratory==

	All laboratory analyses must be performed by experienced laboratory staff.		All laboratory analyses must be performed by experienced laboratory staff.

@@ Line 4: / Line 4: @@
 <br>
-=Sampling and preservation=
+==Sampling and preservation==
 [[File:Table_4.1.jpg|400px|thumb|right| Table 4.1 Overview of commercially available semi-quantitative arsenic field test kits (this list does not include all available kits, and is not intended as an endorsement of any of the companies or products listed)]]For both field and laboratory testing, it is important that correct sampling procedures be followed. To ensure that the sample is representative, it should be freshly drawn from the aquifer. The groundwater should be pumped to ensure that at least one well volume of water is removed before collecting a sample. An alternative is to measure dissolved oxygen and/or pH can in the pumped water until the parameters have a constant value, before taking a sample. The acid-washed sampling bottle should be rinsed three times using the pumped water, making sure to keep the lid clean, before the sample is collected for analysis. Depending on the analytical method chosen, the arsenic measurement can be carried out directly on-site at the water source, or as soon as possible back in the laboratory.
@@ Line 15: / Line 15: @@
-=Field test kits=
+==Field test kits==
 [[File:Table_4.2.jpg|400px|thumb|right| Table 4.2 Overview of commercially available quantitative arsenic field test kits (this list does not include all available kits, and is not intended as an endorsement of any of the companies or products listed)]]Various arsenic field kits are commercially available (Tables 4.1, 4.2). The most commonly used field test methods rely on the chemical reduction of arsenic present in the sample to arsine gas, which then reacts with other chemicals on a test paper or in an indicator tube to produce a colour with an intensity proportional to the arsenic concentration. The tester then compares the colour with a calibrated colour chart. In some field testing equipment, a digital photometer is used to measure the colour intensity, which eliminates human error.
@@ Line 22: / Line 22: @@
-=Arsenic analysis in the laboratory=
+=0Arsenic analysis in the laboratory==
 All laboratory analyses must be performed by experienced laboratory staff.
@@ Line 29: / Line 29: @@
-=Other semi-quantitative field test kits=
+==Other semi-quantitative field test kits==
 The Asia Arsenic Network, an early player in arsenic testing and kit development, continues to market an inexpensive kit with a range of 20–700 µg/L in Bangladesh. A variation on this kit, measuring arsenic from 10–500 µg/L, was developed by the Environment and Public Health Organization, Nepal.

← Older revision	Revision as of 11:04, 10 May 2018
(No difference)

@@ Line 1: / Line 1: @@
 Inorganic arsenic in groundwater is found in two different oxidation states: As(III) (arsenite) and As(V) (arsenate). There are also organic forms, but these are rare in drinking water. Both As(III) and As(V) are toxic, but the two species behave somewhat differently in the environment. The testing methods described in this manual give total inorganic arsenic concentrations, which are adequate for most general purposes. Specialised techniques are needed to tell whether arsenic is present as arsenite or arsenate. The detection range of interest is 10 to 50 µg/L (the typical range of national standards for arsenic). Maximum concentrations of naturally occurring arsenic in groundwater can exceed 1000 µg/L.
 <br><br>
 __TOC__