New Developments in Atomic Spectroscopic Methods - with a Focus on Standardisation- Dr Ulrich Borchers PRIMER CONGRESO INTERNACIONAL DE DOCENCIA E INVESTIGACIÓN EN QUÍMICA México, 27th - 29th October 2010

Dr Ulrich Borchers Food Chemist Head of Dept. Water Quality Education Exam in Food Chemistry (Technical University Braunschweig) PhD Thesis: „Turnover of Nitrogen in Soil and Groundwater“ (Institute for Microbiology at TU Braunschweig) Projects / memberships Interlaboratory trials, Education of sampling personnel Chairman CEN Technical committee „Water quality“ Member of the DIN main committee water analysis Main activities Chemical and microbiological analysis of water Assessment of products for water treatment Sampling techniques and strategies Education of health authorities staff Technical CEO IWW Nord

Topics Performance Requirements Atomic Absorption Spectrometry Routine methods and recent developments Revision of existing Hg methods (ISO/DIS 12846) Atomic Fluorescence Spectrometry Mercury Hydride Forming Elements ICP-OES What’s new in ISO 11885 (2009) ICP-MS Is ISO 17294 still state-of-the-play? Summary and Outlook

Heavy Metals to be Monitored (WFD) DECISION 2455/2001/EC List of Priority Substances (33) Priority Substances Present a significant risk to or via the aquatic environment Priority Hazardous Substances Subset of priority substances, which are toxic, persistent, liable to bioaccumulate or give rise to equivalent level of concern 4

Priority Substances/Other Pollutants Trichloromethane Octylphenol Simazine Priority Substances Other Specific Pollutants Alachlor Atrazin Benzene Chlorpyrifos Chlorfenvinphos Di(2-ethylhexyl)phthalate (DEHP) 1,2-Dichloroethane Diuron Dichloromethane Fluoranthene Isoproturon Lead and its compounds Naphthalene Priority Hazardous Substances Pentabromodiphenylether Anthracene Cadmium and its compounds C10-C13-Chloroalkanes Hexachlorobenzene Hexachlorobutadiene Hexachlorocyclohexane Endosulfan Mercury and its compounds Nonylphenol Pentachlorobenzene Polyaromatic Hydrocarbons (PAH) Tributyltin compounds Pentachlorophenol Trichlorobenzenes Nickel and its compounds Trifluralin DDT / p,p‘-DDT Aldrin Dieldrin Endrin Isodrin Carbontetrachloride Tetrachloroethylene Trichloroethylene 5

Requirements: QA/QC Commission Directive laying down, pursuant to Directive 2000/60/EC of the European Parliament and of the Council, technical specifications for chemical analysis and monitoring of water status Provision of data of proper scientific quality Basis for programme of measures Comparability of monitoring results across Europe Implementation of common principles and harmonised procedures for chemical monitoring 6

Commission Directive – Draft Proposal Standardised methods and other validated method are to be used Any method provided it is properly validated and meets certain performance criteria may be applied Requirements on analytical methods Validation according to EN ISO 17025 Limit of Quantification  30 % of relevant EQS Relative target Uncertainty  50 % If there is no EQS or if existing methods do not meet the criteria „Best available technique“

LOQ Requirements for the 4 priority metals LOQ [ng/l] (30 % of lowest EQS) AAS ICP-OES ICP-MS Cadmium 24  (IWW = 30 ng/l)   Mercury 15  (AFS also OK) Lead 2160 Nickel 6000

Topics Performance Requirements for WFD monitoring Atomic Absorption Spectrometry Routine methods and recent developments Revision of existing Hg methods (ISO TC 147/SC2/WG61) Atomic Fluorescence Spectrometry Mercury Hydride Forming Elements (ISO TC 147/SC2/WG53) ICP-OES What’s new in BS EN ISO 11885 (2009) ICP-MS short outlook to relevant methods for DW Summary and Outlook

AAS in Water Analysis (1) The Initiation! May 1952: First idea on F-AAS by Sir Alan Walsh (born 1916 in England, BSc/MSc in Manchester) 1961: first publication on the „graphite tube“ by Boris L´vov 1962: first commercial F-AAS system

Standardisation of Methods: Co-operation BSI with CEN and ISO BSI Committee EH/3 „Water analysis“ British “mirror committee” of the respective European and International committee CEN TC 230 „Water Analysis“ ISO TC 147 „Water Quality “

Existing Set of Methods Nearly complete set of BS or BS EN (ISO) methods for relevant metals in water Lots of single element standards But also horizontal standards e.g. BS EN ISO 15586 (22 elements by GF-AAS) Complete list see: http://www.bsi-global.com/en/Search-Results/?q=atomic+absorption Recent revisions: Flow systems for HG (instead of batch systems) More general description of light sources More performance based approaches Alternatives for digestion techniques Separate standards for digestion (BS EN ISO 15587-1/-2)

Overview: Digestion Techniques for Water batch systems Continuous systems Open systems Reflux systems UV systems Ultrasonic systems Closed systems Convective heat transfer Microwave assisted Convective heat transfer Microwave assisted

High-Resolution Continuum Source AAS ..... The most interesting development in AAS in the last few years. The advantages Just one light source for all elements Xenon short-arc lamp (W-X-lamp alternatively) All AAS elements are pre-configured Sequential multi-element analysis (like ICP-OES) as standard charge-coupled device (CCD) Simultaneous background correction Easy to operate and robust Improved analytical performance More analytical possibilities

AAS with continuum source (scheme) Optical pathway: LS AAS Optical pathway: CS AAS

High Resolution AAS with Continuum Source - resolution LS AAS versus CS AAS Line Source AAS emission Intensity of the Mn line source Manganese–Triplet: 279,4817 nm 279,8269 nm 280,1085 nm Continuum source AAS absorption spektrum

Topics Performance Requirements for WFD monitoring Atomic Absorption Spectrometry Routine methods and recent developments Revision of existing Hg methods (ISO TC 147/SC2/WG61) Atomic Fluorescence Spectrometry Mercury Hydride Forming Elements (ISO TC 147/SC2/WG53) ICP-OES What’s new in BS EN ISO 11885 (2009) ICP-MS short outlook to relevant methods for DW Summary and Outlook

Existing Hg AAS Standards in the Field of Water A) methods without Enrichment: ISO 5666 standard, 1999-05 Water Quality – Determination of Mercury BS EN 1483 standard, 2007-05 Water quality - Determination of mercury - Method using atomic absorption spectrometry

Existing Hg AAS Standards in the Field of Water B) Methods with Enrichment: ISO 16590 standard, 2000-12 Water Quality – Determination of Mercury after Enrichment by Amagalmation BS EN 12338 standard, 1998-10 Water Quality – Determination of Mercury after Enrichment by Amagalmation

Aim of the Discussion on the Revision of Hg Standards Main items of discussion were: To consider state-of-the-art technology e.g. High resolution CS AAS e.g. modern systems for digestion Is the time high for standards on speciation analysis of Hg? Result: Discussion on robust methods is still open No surveillance limits for Hg species exist For investigative monitoring and specific questions helpful Standardisation should not start at the time being

Strategy for the New BS EN ISO Standard! Only 1 standard for Hg by AAS is needed with 2 alternatives (2 parts) Part 1: Hg without enrichment Part 2: Hg with enrichment (amalgamation) Only one reduction reagent (Sn(II)Cl) as described in BS EN ISO 17852 (Harmonisation of approaches!) No alternative digestion steps NaBH4 in the informative Annex if it can be shown that it works in combination with the new digestion

Strategy for the New BS EN ISO Standard! Working range: 0,005 µg/L with enrichment / 0,1 µg/L without Stabilization of samples / Pre-digestion: Potassium bromate - Potassium bromide digestion Note: reduction of bromate (detoxification!) Reagent should be added in the lab (health/safety hazards) Elimination of excessive oxidising reagent L-ascorbic acid solution, ρ(C6H8O6) = 100 g/l Reduction of Hg Tin(II)chloride solution, ρ(SnCl2 ⋅ 2H2O) = 20 g/l Atomizer Cold vapour generation system Quartz or glass tube atomizer Background correction recommended

Strategy for the New BS EN ISO Standard! Automated stand-alone mercury flow systems flow injection systems or continuous flow systems should be allowed Radiation source, e.g. hollow cathode lamps electrodeless discharge lamps. continuum radiation source (e.g. a Xenon short arc lamp) Formation of the CV continuous flow vapour generator Enrichment by amalgamation of Hg Quarz tube with suitable heating and absorbent (e.g Gold-Platinum Gauge) other absorbents are allowed if the user demonstrates the fitness-for-purpose desorption of Hg at 600° C (minimum)

Stragegy for the new EN/ISO standard! Types of calibration standard calibration standard addition method Validation data A new Interlab trial has to be performed Samples with low Hg conc. are needed to prove the application range e.g. drinking water with Hg = 20 ng/l Informative Annexes no alternatives with respect to the Bromine Chloride combined preservation and digestion step NaBH4 has to be checked whether it works with the potassium bromate/bromide reagent

State of the Work and Further Steps ISO Committee Draft (CD) 12846 Water quality — Determination of mercury - Method using atomic absorption spectrometry (AAS) with and without enrichment Deadline for CD comments: 2009-03-23 Preparation of the Draft International Standard (DIS) version for enquiry until end of July 2009 Interlaboratory trial for the validation of the method End of 2009

Topics Performance Requirements for WFD monitoring Atomic Absorption Spectrometry Routine methods and recent developments Revision of existing Hg methods (ISO TC 147/SC2/WG61) Atomic Fluorescence Spectrometry Mercury Hydride Forming Elements (ISO TC 147/SC2/WG53) ICP-OES What’s new in BS EN ISO 11885 (2009) ICP-MS short outlook to relevant methods for DW Summary and Outlook

Existing Hg AAS Standards in the Field of Water C) Methods using AFS instead of AAS: EN 13506 standard, 2002-04 Water quality — Determination of mercury — Method using atomic fluorescence spectrometry BS EN ISO 17852 standard, 2006-06 Water quality — Determination of mercury — Method using atomic fluorescence spectrometry EPA 1631: 2002-06 Method 1631, Revision E: Mercury in Water by Oxidation, Purge and Trap, and Cold Vapor Atomic Fluorescence Spectrometry EN 13506 is now withdrawn as ISO 17852 has been published

Relevant Items to Mention AFS is the most sensitive technique for Hg! In Germany excellent perfomance data in water PTs Differences between BS EN 13506 and BS EN ISO 17852 EN 13506: Potassium Dichromate as preservation reagent ISO 17852: Potassium bromate – Potassium bromide Most relevant problems in practical application Blanks (lab and reagents!!)

Statistical Data for Hg by AFS (CEN/ISO Interlaboratory Trial)

Hydride Forming Elements by AFS ISO/CD 23914-1 “Determination of antimony – Part 1: Method using hydride generation atomic fluorescence spectrometry (HG-AFS) ISO/DIS 17378-1 “Determination of arsenic – Part 1: Method using hydride generation atomic fluorescence spectrometry (HG-AFS) ISO/DIS 17379-1 “Determination of selenium – Part 1: Method using hydride generation atomic fluorescence spectrometry (HG-AFS)

Hydride Forming Elements by AFS ISO/CD 23914-1 “Determination of antimony – Part 1: Method using hydride generation atomic fluorescence spectrometry (HG-AFS) ISO/DIS 17378-1 “Determination of arsenic – Part 1: Method using hydride generation atomic fluorescence spectrometry (HG-AFS) ISO/DIS 17379-1 “Determination of selenium – Part 1: Method using hydride generation atomic fluorescence spectrometry (HG-AFS) All 3 projects are cancelled due to massive exceedance of target dates (dormant stage)

Topics Performance Requirements for WFD monitoring Atomic Absorption Spectrometry Routine methods and recent developments Revision of existing Hg methods (ISO TC 147/SC2/WG61) Atomic Fluorescence Spectrometry Mercury Hydride Forming Elements (ISO TC 147/SC2/WG53) ICP-OES What’s new in BS EN ISO 11885 (2009) ICP-MS short outlook to relevant methods for DW Summary and Outlook

Topics Performance Requirements for WFD monitoring Atomic Absorption Spectrometry Routine methods and recent developments Revision of existing Hg methods (ISO TC 147/SC2/WG61) Atomic Fluorescence Spectrometry Mercury Hydride Forming Elements (ISO TC 147/SC2/WG53) ICP-OES What’s new in BS EN ISO 11885 (2009) ICP-MS short outlook to relevant methods for DW Summary and Outlook

What’s New in BS EN ISO 11885 (2009) Main changes (compared to the 1998 ed.): New Performance Data from an validation trial in 2006 with 28 labs from 6 countries (UK = 1) Clause 6: Interferences: fully re-structrured; more detailed description Amendments to consider the “State-of-the-play”

Performance Data (Interlab trial 2006) Par l nAP X xass  CVR CVr (2006) CVr (1996) % µg/l Al 24 4,1 120 125,3 95,7 9,8 2,9 4,3 As 18 0,0 63,3 62,5 101,2 8,6 5,8 - B 20 9,1 64,1 63,6 100,9 8,1 3,5 Ba 23 4,2 330 3,9 2,1 3.8 Ca 26 66900 66310 5,7 2,2 6,0 Cd 13,5 14,0 96,3 5,5 1,8 2,8 Co 22 19,4 20,0 96,8 4,5 2,5 Cr 16,2 16,0 9,0 3,1 3,3 Cu 25 634 662,7 3,7 1,2 5,1 Fe 4,0 196 208,5 93,9 4,7 1,7 5,0 K 21 5490 5443 2,3 10,6

Performance Data (Interlab trial 2006) Par l nAP X xass  CVR CVr (2006) CVr (1996) % µg/l Li 16 5,9 131 134 97,8 10,9 2,5 - Mg 26 3,8 10160 10223 99,4 2,6 1,2 6,0 Mn 27 0,0 51,0 53,0 96,3 4,9 1,8 2,7 Na 24 49500 47720 103,8 4,8 1,6 9,7 Ni 23 25,9 26,9 96,4 7,4 3,3 P 21 4,5 884 901,6 98,0 6,8 1,3 1,7 Pb 20 18,4 20,0 92,1 15,8 8,2 S 11,3 19180 4,7 2,1 5,1 Si 17 10,7 3280 3269 100,2 2,3 Sr 495 4,4 Zn 4,2 124 127,5 97,3 1,9 5,4

Other Instrumental Developments (catchwords) Hydride Generation ICP-OES For Arsenic species Microwave Plasma torches (MPT) Ar or He plasma, about 100 Watt New types of nebulizers, e.g. Dual nebulizers Micro-nebulizers A very recommendable review: N.H. Bings; A, Bogaerts, J.A.C. Broekart; Atomic spectrometry; Anal. Chem (2008) 80, pp. 4317-4347

Topics Performance Requirements for WFD monitoring Atomic Absorption Spectrometry Routine methods and recent developments Revision of existing Hg methods (ISO TC 147/SC2/WG61) Atomic Fluorescence Spectrometry Mercury Hydride Forming Elements (ISO TC 147/SC2/WG53) ICP-OES What’s new in BS EN ISO 11885 (2009) ICP-MS short outlook to relevant methods for DW Summary and Outlook

Uranium in Drinking Water DHI (DK) study for COM DG ENV: New Limit for Drinking Water in Europe 10 to 30 µg/l ICP-MS (Uranium-Isotope 238) BS EN ISO 17294-2 LOQ/application range: 0,1 µg/l (to 0,01 µg/l) External calibration Internal Standard Performance data IWW LOQ: 0,02 µg/l Precision: 0,3 % Exp. U: 6 % (at level 2 µg/l) Potentiostatische Anreicherung im komplexierten Zustand auf der Oberfläche einer stationären Quecksilbertropfelektrode und anschließender voltametrischer Bestimmung Komplexbildner: Chloranilsäure

Uranium in German Drinking Waters Name of the Study Max. Value [µg/l] Ratio 2 – 10 µg/l [%] Ratio >10 µg/l [%] Number of results KUS-Study Germany 26,2 7,5 0,5 1790 LfU Bavaria 40 19,7 9,4 704 IWW Northrine-Westfalia 13 8,5 0,2 457 Foodwatch Germany 39 9,3 1,8 8177

IC – ICP-MS coupling: Bromate analysis Limit for Drinking Water in Europe 10 µg/l IC Perkin Elmer HPLC Series 200 Column IonPac AS 16 (4 x 250 mm) NaOH (30 mM), 0,9 ml/min ICP-MS PerkinElmer, Elan DRCII, Performance data IWW LOQ: 0,02 µg/l Precision: 0,3 % Exp. U: 6 % (at level 2 µg/l)

Topics Performance Requirements for WFD monitoring Atomic Absorption Spectrometry Routine methods and recent developments Revision of existing Hg methods (ISO TC 147/SC2/WG61) Atomic Fluorescence Spectrometry Mercury Hydride Forming Elements (ISO TC 147/SC2/WG53) ICP-OES What’s new in BS EN ISO 11885 (2009) ICP-MS short outlook to relevant methods for DW Summary and Outlook

Summary (1) AAS, ICP-OES, ICP-MS and AFS offer an optimal instrumentation Available instruments are in general fit for purpose (also for WFD monitoring) In routine water labs a combination of two techniques is necessary (e.g. HG-AAS/AFS and ICP-MS or ICP-OES) None of these classical techniques is going to be superseded High automation level guarantees marketable routine analysis

Summary (2) Atomic spectrometry takes the centre stage in inorganic water analysis Modern methods meet high demands on specificity, selectivity, sensitivity Enjoyable amount of innovation from research and practice Routine and surveillance analysis rely on standardised methods