A Simple Spectrophotometric Method for the Quantitative Analysis of Phosphate in the Water Samples

Abstract

A simple spectrophotometric method was used to determine the phosphate content in the water sampels. The method is based on the formation of molybdenum blue complex from the reaction of orthophosphate and ammonium molybdate followed by reduction with ascorbic acid in the aqueous sulfuric acid medium. The color intensity of the molybdenum blue complex is proportionally to the phosphate content in the solution. The system obeys Lamber-Beer’s Law at the 890 nm in the concentration range of 0.1-1 mg P/L and the linier calibration graph was obtained with the slope, 0.6334, intercept, 0.0074 and correlation coefficient of 0.9988. This official method was also used for the quantitative analysis of phosphate in the water samples and the satisfactory result was obtained. The range of phosphate concentration in the water samples are 0.033 – 2.943 mg P/L.

Bacterial Endophytes from Vitis vinifera L. – Metabolomics Characterization of Plant‐Endophyte Crosstalk

“…0.5 ml of supernatant was mixed with 49.5 ml of NBRIP medium [22] and cultivated for 7 days (130 RPM; 24 °C in dark); each day a 1 ml sample was taken, centrifuged (10 min 10 000 g) and the concentration of phosphate was determined spectrophotometrically at A 882 by the ammonium molybdate‐ascorbic acid method [23] …”

“…0.5 ml of supernatant was mixed with 49.5 ml of NBRIP medium [22] and cultivated for 7 days (130 RPM; 24 °C in dark); each day a 1 ml sample was taken, centrifuged (10 min 10 000 g) and the concentration of phosphate was determined spectrophotometrically at A 882 by the ammonium molybdate-ascorbic acid method. [23] Nitrogen Fixation 0.5 ml of supernatant was mixed with 49.5 ml of NFGMM [24] and cultivated for 7 days (130 RPM; 24 °C in dark); each day a 1 ml sample was taken, centrifuged (10 min 10 000 g) and the concentration of ammonium ions was determined spectrophotometrically at A 650 by the method of Baethgen and Alley. [25] Indole-3-acetic Acid Production 0.5 ml of supernatant was mixed with 49.5 ml of Nutrient Broth and cultivated for 7 days (130 RPM; 24 °C in dark); each day a 1 ml sample was taken, centrifuged (10 min 10 000 g) and the concentration of indole compounds was determined by reaction with Salkowski's reagent and the A 535 was recorded.…”

Isolasi Antosianin Kulit Terong Ungu (Solanum melongena) sebagai Biosensor Pendeteksi Kandungan Bahan Kimia pada Makanan

“…Karena dalam hal ini natrium nitrit legal digunakan dalam produk daging olahan, maka pengembangan biosensor ini dibuat untuk mendeteksi penggunaan natrium nitrit di atas ambang batas penggunaan yang telah ditentukan. Karena jika penggunaan melebihi batas maksimum dapat menyebabkan efek yang negatif bagi kesehatan (Habibah et al, 2018). Sehingga dalam pengujian pada makanan yang menjadi sumber acuan adalah hasil uji selektivitas perlakuan 7 dan perlakuan 8, yakni konsentrasi 5% (oranye kekuningan) dan 10% (oranye tua).…”

“…Biosensor pendeteksi untuk daging olahan sangat perlu untuk dilakukan terutama pada produk daging olahan seperti kornet dan sosis. Berdasarkan hasil penelitian (Habibah et al, 2018) menunjukkan bahwa 6 sampel dari 18 sampel daging olahan yang diujikan, terindikasi mengandung natrium nitrit di atas batas maksimum yang telah ditetapkan oleh Kemenkes RI yakni sebesar 125 mg/kg berat badan (Pulungan, 2018).…”

“…Pengembangan biosensor dengan media kertas whatmann ini sangat efektif dan efesien untuk dikembangkan, mengingat sebelumnya untuk menguji kandungan natrium nitrit pada daging olahan memerlukan alat yang tidak mudah untuk di dapat dan diaplikasikan secara luas. Seperti penelitian (Habibah et al, 2018) yang menguji penggunaan natrium nitrit pada daging olahan di atas batas maksimum menggunakan spektofometer uv-vis. Dan juga penelitian (Wulandari et al, 2018) yang melakukan pengujian menggunakan uji spektrofotometri uv-vis.…”