An Automated Multi-Pumping Pulsed Flow System with Spectrophotometric Detection for the Determination of Phosphate in Natural Waters

Abstract

In this work, an automated multipumping pulsed flow system was implemented for the determination of phosphate in natural waters. The developed flow approach was based on the spectrophotometric determination of phosphate by using the vanadomolybdate reaction. The exploitation of a very simple manifold configuration relying on the utilization of just two active components, in this case two solenoid actuated micropumps that were accountable for sample and reagent insertion and commutation, reaction zone formation, and solutions propelling, provided a great operational and optimization simplicity, low reagent consumption, and waste minimization.Linear calibration plots for phosphate concentrations of up to 20 mg L À1 (R 2 ¼ 0.999, n ¼ 6) were obtained, with a detection limit of 0.2 mg L À1 . The sampling rate was about 60 samples per hour. The system was applied to the monitoring of phosphate in local streams at specific sampling stations.

Electrochemiluminescence Sensor for Phosphate Ions Based on Europium(III)‐Modulated CdSe Quantum Dots

“…When Eu 3 + ions were added, the CdSe QDs tended to aggregate, resulting in the formation of huge complexes ( Figure 1B). However, the aggregates formed are redispersed with the addition of PO 4 3À ions ( Figure 1C), which confirmed that the introduction of PO 4 3À ions disrupted the Eu 3 + induced CdSe QDs aggregations because Eu 3 + ions have a higher affinity for oxygen-donor atoms from PO 4 3À ions. UV-vis and PL spectra were also used to characterize the obtained CdSe QDs, CdSe QDs-Eu 3 + aggregates and CdSe QDs-Eu 3 + /phosphate, respectively.…”

“…Figure 3B shows the ECL intensity of CdSe QDs at different pH values (4)(5)(6)(7)(8)(9)(10)(11). Experiments show that, with an increasing solution pH from pH 4 to 11, the ECL intensity of the CdSe QDs film gradually increases for the pH 4 to 9 and then decreases with the further increasing pH value.…”

“…Briefly, 23 mg of NaBH 4 were dissolved in 10 mL H 2 O contained in a small vial with a septum and cooled with ice. 15.8 mg Se powder were added to a solution of NaBH 4 and stirred until completely dissolved under constant cooling conditions and slow N 2 flow. At the same time, 48.6 mg CdCl 2 · 2.5 H 2 O and 45 mL MPA were dissolved in 50 mL H 2 O.…”

“…Besides, some health problems, such as hyperparathyroidism, vitamin D deficiency, and fanconi syndrome, can be diagnosed by measuring phosphate anions concentrations in body fluids [2]. Accordingly, considerable detection strategies for phosphate anions and their derivatives have been developed including chromatography, spectrophotometry [3,4], fluorometry [5][6][7], electrochemical analysis [8,9], and enzymatic biosensors [10]. However, the drawbacks of most of these techniques are that they often require time-consuming sample pretreatment procedures, sophisticated instrumentation, large sample volumes, or specialized skills.…”

Inside Cover: Bio‐Inspired Transition Metal–Organic Hydride Conjugates for Catalysis of Transfer Hydrogenation: Experiment and Theory (Chem. Eur. J. 7/2015)

“…Besides, some health problems, such as hyperparathyroidism, vitamin D deficiency, and fanconi syndrome, can be diagnosed by measuring phosphate anions concentrations in body fluids 2. Accordingly, considerable detection strategies for phosphate anions and their derivatives have been developed including chromatography, spectrophotometry 3, 4, fluorometry 5–7, electrochemical analysis 8, 9, and enzymatic biosensors 10. However, the drawbacks of most of these techniques are that they often require time‐consuming sample pretreatment procedures, sophisticated instrumentation, large sample volumes, or specialized skills.…”