Padua, 21 st January 2015

Transcription

1 ODOUR MEASUREMENT TECHNIQUES Maurizio Benzo Padua, 21 st January 2015

2 ODOUR ANALYSIS TECHNIQUES CHEMICAL ANALYSIS SENSORIAL ANALYSIS GC-MS GC-FID e-nose GC-O OLFACTOMETRY FIELD SURVEY COMBINED ANALYSIS

3 GC-MS SYSTEM EQUIPPED WITH THERMAL DESORBER

4 SOLID PHASE MICRO EXTRACTION (SPME) ADSORBING FIBER

5 GC-MS: BIOFILTER EMISSION DIMETHYLSULFIDE [rotten vegetables] DIMETHYLDISULFIDE [cooked cabbage] LIMONENE [citrus peel] TERPENES [pine resin]

6 OLFACTOMETRY: DEFINITIONS EROM (European Reference Odour Mass) 1EROM= 123 µg n-butanol evaporated in 1 cubic meter of standard air (293 K, kpa), equivalent to 40 ppb v/v ODOUR CONCENTRATION It is measured in ou E /m 3, European olfactometric units per cubic meter equivale alla sensazione olfattiva provocata da 1EROM 1 ou E /m 3 It is equivalent to olfactive perception produced by 1 EROM, i.e. by 40 ppb of n- butanol ODOUR THRESHOLD (OT) Odour perception threshold for 50% of panelist

7 EUROPEAN NORM EN THE PANEL Selection, recruiting and training of panelists: individual sensitivity to n-butanol must be in the range ppb OLFACTOMETRIC MEASUREMENT Each sample is presented to eight panelists for three times: Result is calculated by geometrical mean of 24 values DATA EXCLUSION If panelists make too many errors, or their values are too far from the mean, values are discarded.

8 AIR SAMPLING NALOPHAN BAGS VACUUM PUMP (LUNG EFFECT)

9 AIR SAMPLING COMPOSTING PLANT: BIOFILTER EMISSION HOOD

10 AIR SAMPLING COMPOSTING PLANT: SCRUBBER EMISSIONS PIPELINE

11 AIR SAMPLING DIFFUSE EMISSIONS BY COMPOSTHEAP VACUUM PUMP AIRFLOW FROM CYLINDER FLUX CHAMBER

12 OLFACTOMETRIC LAB ACTIVE CHARCOAL FILTERS AIR CONDITIONER OLFACTOMETER

13 OLFACTOMETER SCENTROID mod. SS600 6 PLACES FOR PANELISTS

14 OLFACTOMETER SCENTROID mod. SS600 PANELIST S PLACE

15 OLFACTOMETER SCENTROID mod. SS600 PANEL LEADER S PLACE

16 PANEL AT WORK!

17 MEASUREMENT OF INDIVIDUAL THRESHOLD WITH AN OLFACTOMETER PROGRESSIVE SAMPLE DILUTIONS A gas sample, e.g. n-butanol at a concentration of ppb, is presented to panelists at decreasing dilutions in step of 2: the sample is diluted with pure air 640 times, 320 times, 160 times, 80 times, and so on. If a panelist perceives an odour at the 160 times dilution, but not at 320 times, his odour threshold will be in the middle, so threshold dilution is calculated as geometrical mean of the two values, (160 x 320) ½, or 160 x (2) ½ = 226 Individual odour threshold of panelist is calculated dividing starting n- butanol concentration by threshold dilution, then: 3000 ppb / 226 = 13.3 ppb 13.3 ppb is the individual threshold for the panelist.

18 INDIVIDUAL ODOUR THRESHOLD FOR n-butanol (63 PANELISTS) from 20 to 40 ppb from 40 to 80 ppb

19 n-butanol ODOUR PERCEPTION THRESHOLD: MEDIAN = OT (AT 50%) SOGLIA DI PERCEZIONE PER n-butanolo 1000,00 100,0 20 ppb ppb v/v v n-buoh 10,0 1,0 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% PERCENTUALE CUMULATIVA DEL PANEL

20 ODOUR THRESHOLDS AS REPORTED IN SCIENTIFIC LITERATURE: LOWEST AND HIGHEST VALUES COMPOSTO LOWEST OT HIGHEST OT RANGE butyric aldehyde 4,2 ppb 8300 ppb 2000 limonene 1,0 ppb 200 ppb 200 dimethyl sulfide 0,9 ppb 18,4 ppb 20 dimethyl disulfide 0,024 ppb 82,6 ppb 3500

21 GASCROMATOGRAPHY-OLFACTOMETRY (GC-O)

22 GASCROMATOGRAPHY-OLFACTOMETRY

23 GASCROMATOGRAPHY-OLFACTOMETRY

24 GASCROMATOGRAPHY-OLFACTOMETRY OF COMPOSTING PLANT EMISSION rotten sulfide garlic-like TIC minuti

25 GASCROMATOGRAPHY-OLFACTOMETRY OF COMPOSTING PLANT EMISSION CAMPHENE DIMETHYL TRISULFIDE C3 BENZENES m/z 126 m/z 120 m/z minuti

26 GASCROMATOGRAPHY-OLFACTOMETRY Techniques of GC-O analysis through sample dilutions: CHARM ANALYSIS Introduced by Terry Acree (Cornell University) AEDA: AROMA EXTRACT DILUTION ANALYSIS Introduced by Werner Grosch (Deutsche Forschungsanstalt für Lebensmittelchemie)

27 ETRA ANAEROBIC DIGESTION PLANT IN BASSANO The plant lies 1,5 km far from Cartigliano adn 5 km far from Bassano centre

28 ODOUR FIELD INSPECTION IN BASSANO A GRID OF SQUARES WITH SIDES OF ABOUT 200 M WAS BUILT ON THE TERRITORY AROUND THE PLANT, BASED ON THE FREQUENCY OF COMPLAINTS BY THE RESIDENTS (CARTIGLIANO) THE GRID IS MADE OF 33 CELLS AND 48 INTERSECTION POINTS AND IS MAINLY DEVELOPED AT THE SOUTH OF THE TOWN, FOLLOWING THE MAIN WIND DIRECTION

29 ODOUR FIELD INSPECTION IN BASSANO 14 ASSESSORS RECRUITED AND SELECTED MEASURING THEIR OLFACTORY SENSITIVITY TO N-BUTANOL (INDIVIDUAL ODOUR THRESHOLD IN THE RANGE PPB) ASSESSORS WERE TRAINED TO PROPER RECOGNITION OF TYPICAL PLANT ODOURS (BIOGAS, BIOFILTER, GREEN WASTE)

30 ODOUR FIELD INSPECTION IN BASSANO TWELVE DIFFERENT PATHS, EACH ONE CROSSING FOUR NON- ADJACENT CELL VERTICES, WERE CREATED EVERY DAY TWO ASSESSORS MADE DIFFERENT PATHS AT EVERY DAY TWO ASSESSORS MADE DIFFERENT PATHS AT DIFFERENT DAY TIMES (EXCEPT FOR NIGHT TIME, FROM 1 A.M. TO 7 A.M.)

31 ODOUR FIELD INSPECTION IN BASSANO ODOUR ASSESSMENT WAS MADE ON EACH POINT BY SNIFFING THE AIR EVERY 10 SECONDS OVER A PERIOD OF 10 MINUTES (I.E. 60 MEASUREMENTS), AND EVALUATING ANY PERCEIVED ODOUR RECOGNITION OF: - BIOGAS ODOUR - BIOFILTER ODOUR - GREEN WASTE ODOUR - OTHER ODOURS - NO ODOUR

32 ODOUR FIELD INSPECTION IN BASSANO DURING THE CAMPAIGN EVERY POINT WAS VISITED 26 TIMES, BY DIFFERENT PANELLISTS AT DIFFERENT HOURS AND WEEK DAYS SIX MONTHS CAMPAIGN FROM 16 JULY 2009 TO 15 JANUARY 2010

33 CELL ODOUR FREQUENCY CALCULATION MEASUREMENT POINT 1 CELL F% MEASUREMENT POINT 2 MEASUREMENT MEASUREMENT POINT 3 POINT 4 FOR EACH CELL OF THE GRID ODOUR FREQUENCY IS CALCULATED AS THE RATIO BETWEEN POSITIVE ODOUR RECOGNITION IN THE FOUR MEASUREMENT POINTS AND THE TOTAL NUMBER OF MEASUREMENTS ODOUR FREQUENCY IS CALCULATED FOR EACH ODOUR TYPE AND FOR EACH CELL OF THE GRID

34 CELL ODOUR FREQUENCY: BIOFILTER

35 ISOFREQUENCY CURVES: BIOFILTER

36 ISOFREQUENCY CURVES: BIOFILTER

37 ISOFREQUENCY CURVES: BIOGAS

38 ISOFREQUENCY CURVES: GREEN WASTE

39 ISOFREQUENCY CURVES: TOTAL PLANT ODOUR

40 SEASONAL COMPARISON: BIOFILTER SUMMER WINTER

41 SEASONAL COMPARISON: BIOGAS SUMMER WINTER

42 SEASONAL COMPARISON: GREEN WASTE SUMMER WINTER

43 SEASONAL COMPARISON: TOTAL PLANT ODOUR SUMMER WINTER

44 ODOUR FIELD INSPECTION IN BASSANO ADVANTAGES USE OF LOCAL ASSESSORS LESS EXPENSIVE DRAWBACKS PROPER TRAINING OF ASSESSORS MAY BE CRITICAL DIFFICULT RECOGNITION OF UNFAMILIAR ODOURS

45 THANK S FOR ATTENTION! maurizio.benzo@osmotech.it