There is an assumption that water quality may not be affected during traansportation except for the life of living organisms present in the samples. This i need to elucidate some water quality parameters.
It depends on the parameter that will be analyzed. Temperature, light, toxicity and pH are some of these items that should be taken into consideration. Each parameter has its own sampling, reservation and transportation procedure that must be followed to get the write results. Use the APHA 2012 standards from this link.
https://revistas.ucm.es/index.php/ANHM/article/viewFile/40440/38790
i concur with the above suggestions but to say more: it is truly parameter dependent the ones of interest which can also be dependence on the biological attributes that its activities could bring variation to the actual parameters immediately after sampling (nitrate - ammonia - phosphates) which are usually light dependent.
It depends on what you are analyzing for and how you are analyzing it.
Refrigerate the samples by storing the sample bottles in an ice-packed container. You can as well acidify the samples by adding 2 drops of either (HNO3, HCl or H2SO4)
As said before by colleagues, it depends for what you would like to analyse and what could happen to your samples if you don't protect from loss of original signature (chemical, isotopic, bacteriological, etc.) due to potential interactions with carrying medium as well as with immediate environment due to changes in temperture, light, pH, dissolution of gases etc...
For instance, if you analyse for chemistry then you should prevent precipitation of minerals for cations and leave your samples as are for anions. For stable isotopes, nothing more than prevent fractionation and isotopic exchange tht are probable mainly due to change of phase (liquid to vapor, liquid to solid). Most of the time tightly closed bottles will be OK. For bacteriological analyses, keeping cold (
A good water quality data should be representative of the entire status of the water resource in terms of the hydrochemistry/hydrogeochemistry, biochemical, microbial, metal pollution etc. This therefore means that, the generation of a good water quality data begins from collection of the water samples to analysis in the laboratory.The integrity of the water quality data generated depends on a number of factors. These include:
1. The type of sampling bottle used
2. Adherence to best practices in cleaning the sampling bottles prior to sample collection
3. Adherence to best practices in the field
4. Adherence to best practices in the preservation of the samples prior to laboratory analysis
5. Adherence to best laboratory analysis practice.
The type of sampling bottle used in sampling water resources depends on the parameters of interest. For instance polypropylene containers are used for sampling water resources for the analysis of the common parameters for potable purposes, while dark glass bottles are used for the analysis of organic compounds such as pesticides and PAHs.
In adhering to the best practices in cleaning the sampling bottles, it is required that, the sampling bottles be thoroughly cleaned with detergent and rinsed using 4-1 acid-washed and finally dried.
In terms of adherence to best practices in the field, it is expected for instance that, in collecting water samples from boreholes, the borehole be pumped for sometime (at least five mins) to ensure a representative sample collection and if it is a surface water, the sample be taken at a depth below the surface. It is also important that, physical parameters be taken in the field just after sampling to ensure that, the water Temp, pH and conductivity are not altered due to environmental changes.
Preservation of the samples is one other important factor in ensuring the integrity of the samples.The samples should be kept on ice in an ice-chest under 4 degrees celcius and transported to the laboratory and kept in the refrigerator until analysed (within the shortest possible time, normally within one weeks). Typically for the analysis of metals, it is expected that, the samples be fixed in the field using Conc. HCO3.
You may contact sampling protocols described by Claasen (1982) and Barcelona et al. (1985).
Regarding the analysis of the samples since each parameter requires a prescribed protocol, you may refer to Standard Methods for the Examination of Water and Wastewater (APHA 2011).
Sampling is an important step in determining the water quality. to this end, water sampling must meet a few regulations of water quality standards.
http://www.who.int/water_sanitation_health/dwq/2edvol3d.pdf
I will not talk about methodologies because there are a lot you can do to preserve integrity of your sample from collection to point of analysis. Rather the principle is keep the sample in conditions as close as possible to the state of the sample source.
Thank you all for your contributions its laudable and very helpful. However, the concentration of acid to be use was not mention. I need further clarification.
After all the comments made with hindsight that seem fantastic to me only to emphasize that my biggest problem during the follow-up of samples has taken place during the taking of the same one because the operator has hands with traces of coliforms or other substances or by rubbing the walls or parts of the deposit that have contaminated it without realizing what has caused having to repeat the taking and analysis
it depends with the specific parameter that you would want to analyse ,basically every parameter has a specific way of maintaining its integrity and ensuring that you do not lose any analyte in collection and transportation .Refer to APHA standard methods of water and wastewater analysis manual to ensure you use the correct preservation technique and chain of custody during collection and transportation before analysis
The samples should be refrigerated (during transportation) prior to analyses in the laboratory. In fact the best is to carry out the analyses right there in the field using portable hydrogeochemical kits to avoid changes in the chemical parameters before it gets to the laboratory.
Regards
Preferably use glass bottles for sampling as plastic containers under intense sunlight is said to release some chemical components which may affect the physiochemical composition of sampled water.
Proper plans should be made ahead of time. There should be proper bottles, field equipment and preservatives, such as ice. It’ is right to obtain sampling bottles from the lab where analysis is run, as some bottle sizes and preservatives used can differ slightly. De-contamination of devices should be carried out as cross-contamination can occur if sampling devices are not properly sterile. Equipment blanks is necessary to demonstrate that all sampling and sample processing equipment is free of contaminant. Do not take samples near the bottom and do not skim the water surface in order to prevent the agitation of bottom sediments or surface floating debris. Also, collect samples upstream of the sampler and after any disturbed sediments have been cleared by the current. When sampling wetlands or other slow-flowing or non-flowing water bodies, it is essential to reach out into the water body away from the bottom sediment stirred up when wading to the sampling point to ensure an undisturbed surface water sample. A dip sampler may be needed to prevent disturbed bottom sediments in the sample. Moreover, samples may be collected from a boat. Samples should not be filtered near a running vehicle motor or a generator for risk of contamination by gas/oil fumes. Samples must be collected in the appropriate sample containers with the correct preservative. If samples are not properly prepared, inaccurate results may result due to extraneous components.
The best is to' carry out the analysis on the field using multifunction water qiality device/equipment that uses batery or water quality analysis kits.
Sample preservation between the field and laboratory until analysis is key and very important in defining the integrity of the data generated, findings and conclusion drawn from it. This is why in science we insist that, the samples collected from an environmental media should be representative. That is to say the sample condition outside of the environmental media should be as close to as possible to its condition in the original medium. Sample preservation and transportation therefore, plays a key role in ensuring 'representativity'. Every water quality parameter requires a kind of preservation prior to analysis though, in all cases water samples are to kept on ice in an ice-chest in order to keep the samples under very low temperatures. Physical parameters such as temp, pH, conductivity etc for instance are to measured in the field due to variations in temperatures which has the potential of effecting the readings. For some parameters samples doesn't need to be fixed (i.e major ions) while others (i.e metals) need fixing using acids ( i.e conc. HNO3). Other water quality parameters also require the use of dark bottles etc.......For further reading, you may see APHA.
please check the below links.
- https://www.who.int/water_sanitation_health/dwq/2edvol3d.pdf
- https://pubs.usgs.gov/wsp/1454/report.pdf
- https://pubs.usgs.gov/twri/twri9a4/twri9a4_Chap4_v2.pdf