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The determination of Silver Nanoparticles in Water sources. Norah Almadani Chem 4101 12/04/2009. What are Ag Nanoparticles.

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what are ag nanoparticles
What are Ag Nanoparticles

Nanoparticles could be of the same dimension as some biological molecules like proteins and nuclic acids therefore, functulizednanoparticles might intrude into the fold of biomolecules structures.

It is possible that nanosilver could pose a threat to the balance of human health. The toxicity of silver exhibited in liver cells was also shown to be mediated by oxidative stress, and silver nanoparticles were found to induce toxicity in germline stem cells2.

Reduction in size to the nanoscale level results in an enormous increase of surface to volume ratio, therefore, more molecules of the chemical are present on the surface, thus enhancing the intrinsic toxicity

bactirial inhibition of ag naonoparticles
Bactirial Inhibition of Ag Naonoparticles

Different shapes of Silver nanoparticles have different affects on bacterial cells; Ag NP’s in the sub 50 nm exhibit increase efficiency in inhibiting wide range of bacteria.

Ag NP’s of 10nm interact with bacterial cell producing electronic effect enhancing the reactivity of the NP’s.

Depending on the geometry of Ag NP’s the toxicity ranges 1-100 microgram.

the problem
The Problem

silver is known to have an anti-microbial activity, and if presence in high concentration in water sources silver may be highly toxic to living systems

Hypothesis

Engineered silver nanoparticles having the size 20nm-200nm have the toxicity to destroy living systems cells and can be found in water sources using analytical techniques.

method of choice icp ms 8
Method of Choice ICP-MS8

Analyteions are then focused by a series of ion lenses into a quadrupole mass analyzer, which separates the ions based on their m/zratio.The mass analyzerconsists of four parallel stainless steel rods to which a combination of AC and DC voltages are applied. The combination of these voltages allows the analyzer to transmit only ions of a specific m/zratio.

Sample is pumped in to the nebulizer mixes with argon where the sample aresole forms, large droplets are removed from the aerosol as it passes through the cool chamber where the fine aerosol are swept to the Chanel of the plasma due to the electric field and travel through high temperature Ar plasma; there aerosol droplets are dried and decomposed and finally ionized.

The detector used is an electron multiplier

slide7

**www.cartage.org.lb/.../ Inductively/icp-sche.gi

**American Society of Mass Spectrometry

slide8

Experimental Design

*Calibration standards

*Then having 6 samples spiked with 100 micg/L Ag

slide10

Sampling Procedure

Solution containing 10ng/mL Ag, Triton X-144 (0.2%) v/v, dithizone (1X10-3 molL-1

Buffer solution of pH 4 (100 mM acetate buffer)

Centrifuging at 3500 rpm for 10 min.

Kept in 45°C thermostatic

bath for 15min

aqueous

Remove by syringe

Cool in ice bath

Formation of

two layers

To reduce viscosity

Add 1.0 molL-1

HNO3 in MeOH

Surfastant rich

phase

slide12

Instrument Selection8

Agilent 7500ce ICPMS

Key features of instrument:

High sensitivity.

Speed.

Removal of Ar- bace interfering species such as Ar2 using H2 reaction mode.

The removal power of the Octapol Reaction System of matrix interference.

conclusion
Conclusion

Ag nanoparticles could pose a threat to the balance of human health

Ag NP”s of different shape cause bacterial inhibition, where the toxicity depends on the geomery

Analytical problem Ag NP’s presence in water sources

Flouresence, FAAS and ICPM are possible methods of determing the concentration of Ag NP’s

Mettod of choice ICPMS

Ag NP’s are extracted from water by (CPE) solid extraction phase

Quantitative measurment of Ag concentration is determined using standards and calibration curves.

reference
Reference

1. EUROPEAN COMMISSION HEALTH & CONSUMER PROTECTION DIRECTORATE-GENERAL SCIENTIFIC COMMITTEE ON EMERGINGAND NEWLY IDENTIFIED HEALTH RISKS (SCENIHR) “The appropriateness of existing methodologies to assess thepotential risks associated with engineered and adventitious products of nanotechnologies” Adopted by the SCENIHR during the 10th plenary meeting of 10 March 2006

2. “Unique Cellular Interaction of Silver Nanoparticles: Size-Dependent Generation of Reactive Oxygen Species” C. Carlson, S. M. Hussain, A. M. Schrand, L. K. Braydich-Stolle, K. L. Hess, R. L. Jones, and J. J. Schlager† “J. Phys. Chem. B 2008, 112, 13608–13619” 

3.”Silver nanoparticles as a new generation of antimicrobials”MahendraRai, AlkaYadav, AniketGade

slide15

4.”Cloud Point Extraction as an Advantageous Preconcentration Approach for Analysis of Trace Silver Nanoparticles in Environmental Waters” Jing-fu Liu, Jing-bo Chao, Rui Liu, Zhi-qiang Tan, Yong-guang Yin, Yuan Wu, and Gui-bin Jiang

6. “Fluorescence properties of Ag nanoparticles in water”, methanolandhexane Om ParkashSiwach,P.Sen _

 7. “Off-line determination of trace silver in water samples and standard reference materials by cloud point extraction–atomic absorption spectrometry” ErsinKilinca*, ViiaLepaneb, AnuViitakb, and BahattinGumgum

 8. aiglent 7500ce https://cp.chem.agilent.com/en-US/Newsletters/accessagilent/2009/jun/pages/envirolab.aspx

9. Skoog, Holler and Crouch, “Principles of Instrumental Analysis”, 6th