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Determination of phosphate in soil extracts in the field: A green chemistry enzymatic method.

Campbell ER, Warsko K, Davidson AM, Bill Campbell WH - MethodsX (2015)

Bottom Line: Measurement of ortho-phosphate in soil extracts usually involves sending dried samples of soil to a laboratory for analysis and waiting several weeks for the results.Absorbance of the completed reaction is measured at 360 nm in open-source, portable photometer linked by bluetooth to a smartphone.The phosphate and phosphorus content of the soil is determined by comparison of its absorbance at 360 nm to a previously prepared standard phosphate curve, which is stored in the smartphone app.

View Article: PubMed Central - PubMed

Affiliation: NECi, Lake Linden, MI 49945, USA.

ABSTRACT
Measurement of ortho-phosphate in soil extracts usually involves sending dried samples of soil to a laboratory for analysis and waiting several weeks for the results. Phosphate determination methods often involve use of strong acids, heavy metals, and organic dyes. To overcome limitations of this approach, we have developed a phosphate determination method which can be carried out in the field to obtain results on the spot. This new method uses: •Small volumes.•An enzymatic reaction.•Green chemistry. First, the soil sample is extracted with deionized water and filtered. Next, an aliquot of the soil extract (0.5 mL) is transferred to a disposable cuvette, containing 0.5 mL of reaction mixture [200 mM HEPES, pH 7.6, 20 mM MgCl2, with 80 nmol 2-amino-6-mercapto-7-methylpurine ribonucleoside (MESG) and 1 unit of recombinant purine nucleoside phosphorylase (PNP; EC 2.4.2.1)], mixed, and incubated for 10 min at field temperature. Absorbance of the completed reaction is measured at 360 nm in open-source, portable photometer linked by bluetooth to a smartphone. The phosphate and phosphorus content of the soil is determined by comparison of its absorbance at 360 nm to a previously prepared standard phosphate curve, which is stored in the smartphone app.

No MeSH data available.


Related in: MedlinePlus

Home screen for smart phone or tablet app. The user can simply read the absorbance at 360 nm for each standard and soil extract sample and record them by hand. Alternatively, the user can set up a list of standards and samples and store them along with the absorbance at 360 nm. The GPS function of a smart phone can be used to establish the location where the soil samples were taken and analyzed, which can be also be saved. The list and data can be saved in the cloud and accessed at a later time using a PC via the internet.
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fig0020: Home screen for smart phone or tablet app. The user can simply read the absorbance at 360 nm for each standard and soil extract sample and record them by hand. Alternatively, the user can set up a list of standards and samples and store them along with the absorbance at 360 nm. The GPS function of a smart phone can be used to establish the location where the soil samples were taken and analyzed, which can be also be saved. The list and data can be saved in the cloud and accessed at a later time using a PC via the internet.

Mentions: Another consideration is the availability of a portable photometer which can be used for measuring absorbance at 360 nm, since this wavelength is not visible it cannot be estimated by eye. To overcome this limitation, we have developed an inexpensive open-source portable photometer capable of measurements at 360 nm: NECi Photometer and software app for smart phone/tablet PC (Fig. 3). The home screen for the smart phone and tablet PC app is shown in Fig. 4. The NECi Field Photometer is perfectly suited to the small volume of the field soil phosphate test and associated smartphone or table PC automatically reports the phosphate content of the sample in mg phosphate/L. The NECi Field Photometer is currently being tested and will be available soon. Other portable colorimeters can be used, if they accept the small cuvette used here.


Determination of phosphate in soil extracts in the field: A green chemistry enzymatic method.

Campbell ER, Warsko K, Davidson AM, Bill Campbell WH - MethodsX (2015)

Home screen for smart phone or tablet app. The user can simply read the absorbance at 360 nm for each standard and soil extract sample and record them by hand. Alternatively, the user can set up a list of standards and samples and store them along with the absorbance at 360 nm. The GPS function of a smart phone can be used to establish the location where the soil samples were taken and analyzed, which can be also be saved. The list and data can be saved in the cloud and accessed at a later time using a PC via the internet.
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4487730&req=5

fig0020: Home screen for smart phone or tablet app. The user can simply read the absorbance at 360 nm for each standard and soil extract sample and record them by hand. Alternatively, the user can set up a list of standards and samples and store them along with the absorbance at 360 nm. The GPS function of a smart phone can be used to establish the location where the soil samples were taken and analyzed, which can be also be saved. The list and data can be saved in the cloud and accessed at a later time using a PC via the internet.
Mentions: Another consideration is the availability of a portable photometer which can be used for measuring absorbance at 360 nm, since this wavelength is not visible it cannot be estimated by eye. To overcome this limitation, we have developed an inexpensive open-source portable photometer capable of measurements at 360 nm: NECi Photometer and software app for smart phone/tablet PC (Fig. 3). The home screen for the smart phone and tablet PC app is shown in Fig. 4. The NECi Field Photometer is perfectly suited to the small volume of the field soil phosphate test and associated smartphone or table PC automatically reports the phosphate content of the sample in mg phosphate/L. The NECi Field Photometer is currently being tested and will be available soon. Other portable colorimeters can be used, if they accept the small cuvette used here.

Bottom Line: Measurement of ortho-phosphate in soil extracts usually involves sending dried samples of soil to a laboratory for analysis and waiting several weeks for the results.Absorbance of the completed reaction is measured at 360 nm in open-source, portable photometer linked by bluetooth to a smartphone.The phosphate and phosphorus content of the soil is determined by comparison of its absorbance at 360 nm to a previously prepared standard phosphate curve, which is stored in the smartphone app.

View Article: PubMed Central - PubMed

Affiliation: NECi, Lake Linden, MI 49945, USA.

ABSTRACT
Measurement of ortho-phosphate in soil extracts usually involves sending dried samples of soil to a laboratory for analysis and waiting several weeks for the results. Phosphate determination methods often involve use of strong acids, heavy metals, and organic dyes. To overcome limitations of this approach, we have developed a phosphate determination method which can be carried out in the field to obtain results on the spot. This new method uses: •Small volumes.•An enzymatic reaction.•Green chemistry. First, the soil sample is extracted with deionized water and filtered. Next, an aliquot of the soil extract (0.5 mL) is transferred to a disposable cuvette, containing 0.5 mL of reaction mixture [200 mM HEPES, pH 7.6, 20 mM MgCl2, with 80 nmol 2-amino-6-mercapto-7-methylpurine ribonucleoside (MESG) and 1 unit of recombinant purine nucleoside phosphorylase (PNP; EC 2.4.2.1)], mixed, and incubated for 10 min at field temperature. Absorbance of the completed reaction is measured at 360 nm in open-source, portable photometer linked by bluetooth to a smartphone. The phosphate and phosphorus content of the soil is determined by comparison of its absorbance at 360 nm to a previously prepared standard phosphate curve, which is stored in the smartphone app.

No MeSH data available.


Related in: MedlinePlus