Salta al contenuto principale
Home

Dedicated to discovery

  • A proposito di ELGA
    • A proposito di ELGA
    • Carriere
    • Eventi
  • Supporto
    • Laboratory Planning
  • Contatti
  • EN
  • DE
  • ES
  • FR
  • PT
  • EN-US
Home
  • Prodotti
    • PURELAB
      • PURELAB® Dispenser
      • PURELAB® Flex
      • PURELAB® Quest
      • PURELAB® Pharma Compliance
      • PURELAB® Chorus 1 Complete
      • PURELAB® Chorus 1
      • PURELAB® Chorus 2
      • PURELAB® Chorus 3
      • PURELAB® Chorus 2 +
    • CENTRA
      • CENTRA® R60/120
      • CENTRA® R200
      • CENTRA® RDS
    • MEDICA
      • MEDICA® 150
      • MEDICA® 7/15
      • MEDICA® BIOX 2024
      • MEDICA® Pro-R & Pro-RE
      • MEDICA® R200
      • MEDICA® EDI 15/30
      • MEDICA® Pro-LPS
      • MEDICA® Pro EDI 60/120
      • MEDICA® BIOX
      • Hubgrade
    • BIOPURE
      • BIOPURE® 300/600
    • PURENERGY® 30
    • ELGA Gamma Completa di Prodotti
  • Applicazioni
    • Analisi microbiologica
    • Biochimica clinica
    • Colture cellulari
    • Cromatografia liquida
      • High Performance Liquid Chromatography
    • Elettrochimica
    • Gascromatografia
    • Genetica
    • High Performance Liquid Chromatography (HPLC)
    • Immunochimica
    • Requisiti dell'acqua per laboratori generici
    • Spettrofotometria
    • Spettrometria di massa
    • Spettroscopia atomica
  • Tecnologie
    • Activated Carbon
    • Electrodeionization (EDI)
    • Filtration
    • Ion Exchange
    • PureSure
    • Reverse Osmosis
    • Ultraviolet
  • Impurità nell'acqua
    • Dissolved Gases
    • Inorganic Compounds
    • Microorganisms & Bacteria
    • Organic Compounds
    • Particulates
  • Conoscenza
    • BROSCHÜREN
    • Blog
    • Casi di studio
    • Acqua ultrapura
    • Guide e libri bianchi
  • Where to buy
  • Contattaci
Home
  • Contattaci
  • Prodotti
    • PURELAB
      • PURELAB® Dispenser
      • PURELAB® Flex
      • PURELAB® Quest
      • PURELAB® Pharma Compliance
      • PURELAB® Chorus 1 Complete
      • PURELAB® Chorus 1
      • PURELAB® Chorus 2
      • PURELAB® Chorus 3
      • PURELAB® Chorus 2 +
    • CENTRA
      • CENTRA® R60/120
      • CENTRA® R200
      • CENTRA® RDS
    • MEDICA
      • MEDICA® 150
      • MEDICA® 7/15
      • MEDICA® BIOX 2024
      • MEDICA® Pro-R & Pro-RE
      • MEDICA® R200
      • MEDICA® EDI 15/30
      • MEDICA® Pro-LPS
      • MEDICA® Pro EDI 60/120
      • MEDICA® BIOX
      • Hubgrade
    • BIOPURE
      • BIOPURE® 300/600
    • PURENERGY® 30
    • ELGA Gamma Completa di Prodotti
  • Applicazioni
    • Analisi microbiologica
    • Biochimica clinica
    • Colture cellulari
    • Cromatografia liquida
      • High Performance Liquid Chromatography
    • Elettrochimica
    • Gascromatografia
    • Genetica
    • High Performance Liquid Chromatography (HPLC)
    • Immunochimica
    • Requisiti dell'acqua per laboratori generici
    • Spettrofotometria
    • Spettrometria di massa
    • Spettroscopia atomica
  • Tecnologie
    • Activated Carbon
    • Electrodeionization (EDI)
    • Filtration
    • Ion Exchange
    • PureSure
    • Reverse Osmosis
    • Ultraviolet
  • Impurità nell'acqua
    • Dissolved Gases
    • Inorganic Compounds
    • Microorganisms & Bacteria
    • Organic Compounds
    • Particulates
  • Conoscenza
    • BROSCHÜREN
    • Blog
    • Casi di studio
    • Acqua ultrapura
    • Guide e libri bianchi
  • Where to buy
  • Contattaci
  • A proposito di ELGA
    • A proposito di ELGA
    • Carriere
    • Eventi
  • Supporto
    • Laboratory Planning
  • Contatti
  • EN
  • DE
  • ES
  • FR
  • PT
  • EN-US
  • Normativa sulla privacy
  • Termini e condizioni
  • Dichiarazioni di conformità legale globale
  • Brevetti
  • Trademarks
  • Impressum
  • Minimizing Contamination During Sample Preparation For Trace Analysis
Analytical Chemistry
Water Purity

Minimizing Contamination During Sample Preparation For Trace Analysis

13 Feb 2020
- by Dr Paul Whitehead

Medical research. Selective focus of new experimental vaccine being in the test tubes

Avoiding Contamination In Sample Preparation

With an increase in the sensitivity of applications correlating with a decrease in detection limits, the effects of contamination from a range of sources has become increasingly important. With a number of sources of errors in chemical and trace analyses, how can you ensure that sample preparation contamination is at a minimum? 

Sample Preparation The Largest Source Of Errors In Trace Analysis

A recent survey in 2013 conducted by the Analytical Methods Committee concluded that sample preparation is the largest source of errors in trace analysis, and during sample preparation contamination is always a major concern.  This is not surprising as detection of 1ppb of an impurity has been equated to finding the proverbial needle in a haystack and 1ppt to finding a contact lens on 100 miles of beach! Like trace analysis both are major challenges which can be seriously affected by other material present.

Contamination can come from a whole range of sources, essentially the equipment used, the environment in which sample preparation work is carried out and the reagents.

High-Purity Water Is Essential

All equipment including storage and wash bottles need to be carefully selected and thoroughly cleaned before use. A final high-purity water rinse is essential. Even then, flexible plastic bottles can be a problem if ultrapure water is stored in them for long.  The graph in figure 1 shows phthalates leaching from a plastic wash bottle over a few days.

Example of phthalate ester contamination from wash-bottles

Example of phthalate ester contamination from wash-bottles

Significant contributors to the contamination from the environment come from the people involved. For example, human sweat is a serious potential source of trace metals. Not surprisingly, it is a major source of sodium but it also contains significant amounts of other metals, as shown in the table, as well as a wide range of organic compounds.

Metal

Typical  Concentration (µg/L)

Zn

960

Cd

24

Pb

62

Fe

630

Cu

14,200

Ni

57

Mn

23

Na

264,000

Trace Metals in Human Sweat

Similarly, cosmetics can contain trace levels of many common metals, especially Bi, Zn, Fe, Cu, Cr, Mg, Ti, Al and Mn.

How To Minimize Direct Contamination

Clearly, direct contamination can be minimized by wearing gloves, masks, snoods and other hair coverings but certified release values for protective clothing should be checked to confirm their suitability for particular analyses and occasional in-house checks carried out.

Indirect contamination from these and other sources via the local atmosphere is always possible and good laboratory practise is essential. To minimize these risks sample preparation is often carried out in closed systems such as microwave digesters. With acid digestion at pressures of up to 100 bar and temperatures reaching 300°C most matrices can be decomposed and dissolved in a closed vessel. Under these conditions, carbon content of organics can be reduced to less than 1%.

In microwave digestion, typically up to 0.25g of sample are reacted with 10mL acid/water mixtures. In this scenario, there is 40 times more reagents than sample and, as a result, impurities in the acid and water are 40 times more significant relative to the sample; i.e. 1 ppb Cu in the reagents will add 40ppb Cu to the sample analysis. Very low impurity levels in the reagents are, therefore, essential. The acids used are often specially purified by sub-boiling distillation. The water needs to be ultrapure water when used in any sample preparation for ultra-trace analyses.

 

Dr Paul Whitehead 

After a BA in Chemistry at Oxford University, Paul focused his career on industrial applications of chemistry. He was awarded a PhD at Imperial College, London for developing a microwave-induced-plasma detector for gas chromatography. He spent the first half of his career managing the analytical support team at the Johnson Matthey Research/Technology Centre,specialising in the determination of precious metals and characterising applications such as car-exhaust catalysts and fuel cells. Subsequently, as Laboratory Manager in R&D for ELGA LabWater, he has been involved in introducing and developing the latest water purification technologies. He now acts as a consultant for ELGA.

To find out more about ELGA Labwater's ultrapure water purification systems click here

 

  • Sales Enquiry
  • Richiedi un Preventivo
  • Technical Support
  • Trova un Partner Approvato

Sales Enquiry

At ELGA LabWater, we have exciting offers and news about our products and services that we hope you’d like to hear about. We will use your information to predict what you might be interested in. We will treat your data with respect and you can find the details in our Privacy Policy.

ELGA LabWater works with a network of Approved Partners. In order to answer your questions or enquiries, we may pass your contact details to an Approved Partner, who may contact you directly. 

I'd like to receive updates from ELGA LabWater & ELGA Approved Partners based on my details.

Richiedi un Preventivo

At ELGA LabWater, we have exciting offers and news about our products and services that we hope you’d like to hear about. We will use your information to predict what you might be interested in. We will treat your data with respect and you can find the details in our Privacy Policy.

ELGA LabWater works with a network of Approved Partners. In order to answer your questions or enquiries, we may pass your contact details to an Approved Partner, who may contact you directly. 

I'd like to receive updates from ELGA LabWater & ELGA Approved Partners based on my details.

Technical Support

At ELGA LabWater, we have exciting offers and news about our products and services that we hope you’d like to hear about. We will use your information to predict what you might be interested in. We will treat your data with respect and you can find the details in our Privacy Policy.

ELGA LabWater works with a network of Approved Partners. In order to answer your questions or enquiries, we may pass your contact details to an Approved Partner, who may contact you directly. 

Call us

Can't find what you are looking for?

Support Number
+44 (0)20 3567 7300
United Kingdom Sales
+44 (0)1628 879 704
United States of America Sales
+1 877-315-3542
France Sales
+33 1 40 83 65 00
China Sales
+86 400-616-8882

 

ELGA LabWater Sede Centrale

Lane End Business Park
Lane End, High Wycombe
HP14 3BY
United Kingdom
T: +44 (0) 203 567 7300
F: +44 (0) 203 567 7205

Casi di Studio

  • Abbott Diagnostics
  • DASA Diagnostica Medica
  • NeoDIN Istituto Medico
  • North Staffordshire NHS Trust
  • Scuola Professionale Olsberg

Risorse

  • Informazioni sull'acqua ultrapura
  • Guide e libri bianchi
  • Tecnologie per la purificazione dell'acqua
  • Applicazioni di laboratorio
  • Impurità nell'acqua
  • Latest Blog
  • Water Purity - Different Types of Pure Water
  • What is Clinical Laboratory Reagent Water (CLSI)?
  • What is Total Organic Carbon (TOC)?

© VWS (UK) Ltd. che opera come ELGA LabWater. 2025 - Tutti i diritti riservati.
ELGA è il marchio mondiale dell'acqua di laboratorio di Veolia.

  • Normativa sulla privacy
  • Termini e condizioni
  • Dichiarazioni di conformità legale globale
  • Brevetti
  • Trademarks
  • Impressum
  • Lingua
    • Deutsch
    • English
    • Español
    • Français
    • Italiano
    • Português
    • 日本語
    • 中文
  • Altri Siti Veolia
    • Veolia
    • Veolia Foundation
    • Veolia Water Technologies
Elga Veolia
TOP

© 2017 ELGA Veolia