Zefon Air-O-Cell CSI Laborotory Manual
Contents
1. Clean Room Monitoring Evaluation of low airborne dust and contaminants from personnel skin cells clothing fibers cosmetics etc Fiber Analysis Asbestos fiberglass cellulose ceramics etc Stack Emissions Fly ash inorganic dust etc Air O Cell CSI ADVANTAGES e The sample collected in the Air O Cell CSI cassette can be examined and re examined by both optical and electron microscopy in any order without significant particle loss or complex sample preparation e Provides excellent detection limits over conventional filter sampling utilizing 25mm or 37mm diameter filter cassettes e Eliminates sample loss to cassette walls known to occur with filter samples from vibration or static charge during sampling and shipment e Eliminates the need for direct handling or preparation of collection media or microscope slides in the field 2 e Eliminates potential cross contamination between samples and during shipping that may occur with other devices e The high chemical stability clarity and ultra smooth surface of the collection media enable a wide range of chemical microbiological and elemental analysis techniques e The unique low carbon x ray background is specifically designed to enable the differentiation of common carbon containing indoor air quality particles soot rubber particles fibers etc in addition to inorganic contaminants e The Air O Cell CSI will work with virtually any kind of sampling pump capable2. of pulling a 15LPM vacuum air flow e The collection efficiency of the A r O Cell CSI cassette has proven to have stable performance at temperatures down to O F depending on humidity PRINCIPLES OF OPERATION The Air O Cell CSI operates on the well established principle of inertial impaction Particles in the air stream are accelerated as they approach the tapered inlet open ing and drawn through a small slit aimed directly at a glass slide This glass slide contains a sticky and optically clear sampling media which can permanently collect and hold particles As the particles come through the slit the air velocity forces the particles to impact into the sampling media while the air stream makes a sharp 90 turn and proceeds around the slide and out of the cassette The air flow path through the A r O Cell CSI cassette is illustrated below in Figure 1 Figure1 AIR FLOW PATH OF THE Air O Cell CSI air flow into cassette an collection i glass p s exit orifice lateral view OPERATIONAL PERFORMANCE The Air O Cell CSI Sampler has been evaluated in commercial and university labo ratories to determine the collection efficiency and operational aspects of the col lector With impactor type samplers the most common measure of efficiency is defined by its cut point curve The cut point also referred to as the 2 50 point is defined by the particle size at which 50 of the particles are collected and 50 pas
3. AIR O CELL CSI Bioaerosol Sampling Cassette For the collection of viable and non viable airborne particles Laboratory amp User Manual _ Air 0 Cell cs me 8 By 02 2009 S before Use Air Op 50 DOD 42 7 4ir o cen C Am By 02 2009 before Use 47 00 Use By 02 2009 d before Use Sampling Equipment Specialists a ae Ri 0 Move Air O Cell CSI Sampling Cassette The Air O Cell Collector for SEM Identification CSI is a unique sampling cassette specifically designed for the rapid collection and quantitative and elemental analysis of a wide range of airborne aerosols With the Air O Cell CSI you can use optical and scanning electron microscopy and x ray analysis on the exact same air sample The Air O Cell CS collects both viable and non viable particulate such as mold spores pollen insect parts skin cell fragments fibers asbestos fiberglass cellu lose etc and inorganic particles Suggested amp potential applications include but are not limited to the following APPLICATIONS Indoor Air Quality Mold spores pollen insect parts dust mites skin cell fragments plant fragments dust fibers combustion emissions etc Home Inspection Mold contamination before or after real estate transactions Flood Restoration Evaluation of mold spore contamination before during and after remediation Allergy Testing Mold spores pollen insect parts dust mites
4. Air O Cell CSI cassette can be prepared for and analyzed using Scanning Elec tron Microscopy SEM This procedure can be done on the same sample after standard optical is performed or without optical examination If optical examination is not performed it is not necessary to rinse the sample however heating of the sample is still required beginning with step 3 Specific fields identified with the opti cal analysis can now be re examined and further evaluated under the SEM Slide preparation for SEM examination Note The adhesive needs to be fully dried heated and cured prior to sputter coat ing and Scanning Electron Microscope analysis This procedure is required to not only prevent out gassing into the electron microscope column but also to prevent micro cracking in the adhesive substrate Throughout the following steps take pre cautions to ensure the sample is not exposed to airborne laboratory contaminants 1 Following optical analysis carefully remove the top glass coverslip from the Air O Cell CSI coverslip by first applying a light rinse of deionized or distilled water and slowly removing the 22 x 22mm coverslip This is best per formed by applying finger pressure on an angle or blunt forceps to avoid breaking the cover slip The stain residue should be lightly rinsed from the sample with deionized or distilled water A second rinse with 50 isopropyl alcohol and deionized or distilled water should be performed immediately follo
5. ab after 10 minutes has elapsed This will ensure even staining of the sample It should be noted that the slide can also be mounted media side up 6 Counting and quantification of sample components is conducted by counting cali brated cross sections of the deposited sample trace The number and type of particles counted per cubic meter of air is calculated based on the length of the deposition trace length of trace actually examined volume of air collected and number of particles counted The Air O Cell CSI particle deposition area at a flow rate of 15 Ipm is approximately 0 8 1 0 mm wide by 14 5mm long yielding an approximate area of 14 5mmz2 The width of the deposition trace will appear to vary slightly with flow rate and the rela tive concentration of deposited particles The density of particle deposition will also vary slightly from the middle to outer edges of deposition For this reason using the deposition trace area is not recommended for direct calculation of particle con centrations The recommended procedure for calculating particle concentrations is based on using the Air O Cell CSI trace length and microscope field diameter and will be discussed below One field of view counted is defined as the calibrated diameter of the microscope field of view in mm covering one cross sectional pass or traverse across the sample deposition trace A typical sample preparation and microscopic counting procedure is illustrated in Fig
6. ny special calibration methods should be employed Because the cassette does not produce significantly measurable back pressure the rotameter can optionally be connected directly to the pump without the Air O Cell CSI cassette in line to calibrate the pump flow rate To begin sampling remove the tape seals covering the inlet and outlet and placed them on the side of the cassette Then connect the Air O Cell CSI cassette to the sampling pump using flexible tubing Turn the sampling pump on for an appropriate sample time ranging from 5 to 10 minutes and both seals replaced after sampling is complete Unlike other impaction or filter sampling devices the Air O Cell CSI cassette can be oriented in any vertical or horizontal direction without concern for sample loss of large particles or vibration Outdoor background samples should always be collected for comparison purposes Sampling in HVAC Systems The Air O Cell CSI cassette design allows for isokinetic sampling of aerosols in Heat ing Ventilation and Air Conditioning HVAC Systems Sampling can be conducted at the supply diffuser or inside most conventional ducts The inlet of the cassette should always be facing into the flow stream The inlet orifice has a cross sectional area of approximately 11 mm 15 mm 165 0 mm2 tapering to a slit with dimen sions of 1 055mm x 14 5 mm 15 30 mm2 Approximate face velocity of the Air O Cell CSI cassette is listed in Table 1 Table 1 Ai
7. quation 1 Two example calculations for mold spores and pollen grains are given below Example 1 Mold Spore Example Microscope field diameter at 900x 0 240 mm Number of traverses 10 Sample volume 15 lpm 10 minutes 15 1000 10 0 150m Mold spore counts 50 14 5mm 1 x x 50 2000 ct m 0 240 x 10 0 15 Example 2 Pollen Example Microscope field diameter at 200x 1 11 mm Number of traverses 10 Sample volume 15 lpm 30 minutes 15 1000 30 0 450 Pollen counts 25 14 5mm 14 5 25 72 grains m 1 11 x 10 5 0 RECOMMENDED MICROSCOPIC COUNTING GUIDELINES Counting amp Identification Guidelines Pollen Entire trace or 100 grains whichever comes first should be examined at a minimum magnification of 200X Identification and speciation should be performed at minimum magnification of 400 Mold Spores A minimum of 15 of the entire trace should be examined or a minimum of 100 mold spores counted whichever comes first Identification and speciation should be performed at minimum magnification of 400 9 Fibers The entire trace or 100 fibers whichever comes first should be examined at a minimum magnification of 200X Other Aerosols And Opaque Particles Skin cell fragments combustion emissions insect parts A minimum of 10 of the entire trace should be examined or a minimum of 100 particles counted whichever comes first SEM EXAMINATION The
8. r Flow Velocity Guide At Orifice And Slit Face Sample Velocity at inlet of Velocity at Flow Rate sample port sample slit Ipm fpm mph fpm mph 15 299 34 4440 50 5 Recommended Sampling Time Intervals Although the Air O Cell CSI cassette can provide excellent detection limits over conventional filter sampling utilizing 25mm or 37mm diameter filter cassettes it is also sensitive to overloading In an appropriately loaded sample the trace should be barely visible and transparent but not opaque or dense If the sample appears highly visible or opaque additional shorter time interval samples should be collected The recommended sampling flow rate is 15 liters per minute lpm Recommended sampling times at 15 lpm for different environmental sampling conditions are given in Table 2 5 Table 2 RECOMMENDED SAMPLING INTERVALS Sampling Time Environmental Dust Conditions minutes 15 Ipm Outdoor sampling on a clean windless day 10 min Clean office environment or outdoors no visible dust 10 min Indoor environment high activity personnel 5 min Indoor environment evidence of drywall renovation or industrial dust 1 min Indoor environment visible dust emissions from point sources present 0 5 min The Air O Cell CSI sampler is recommended to be operated in temperatures be tween O F and 120 F At lower temperatures however ice can accumulate inside the cassette if the relative humidity i
9. s not extremely low After collection of the sample the user should inspect the inside of the inlet for ice or condensation and decrease sample times to avoid ice buildup OPTICAL EXAMINATION Optical analysis of the collected sample should be performed by an experienced Microbiologist Aerobiologist Mycologist or Environmental Microscopist Slide preparation for optical examination The sealing band should be cut and the glass cover slip containing the sample trace removed and placed deposition side up onto a glass microscope slide A small drop of deionized or distilled water should be placed on the microscope slide and between the CSI cover slip to act as an optical coupling agent Preparing the sample in this fashion will allow the CSI cover slip to be easily removed from the glass microscope slide after optical analysis for SEM preparation and sample analysis Note Air O Cell CSI cassettes should only be opened in the laboratory One to two 1 2 drops of staining or mounting media Lacto Phenol Cotton Blue is recommended for mold spore analysis should be placed on the center of CSI cover slip directly on the deposition trace A 22x22mm cover slip should then be slowly placed on an angle over the drop of stain to evenly disperse the stain over the depo sition area Do not press down on the slide during or after staining Excess staining solution should be removed from around the edges of the cover slip with a tissue wipe or cotton sw
10. s through the sampler at a pre determined flow rate The cut point for the Air O Cell CSI Sampler has been determined to be 1 56 microns at a flow rate of 15 LPM This cut point is ideal for fungal analysis because particles smaller than this are not of interest and may even create enough background debris to obscure adequate viewing of the sample and compromising reliable analysis The graph below dis plays the collection efficiency curve for the Air O Cell CSI sampler when used at a flow rate of 15 LPM AIR O CELL CSI COLLECTION EFFICIENCY CURVE COLLECTION EFFICIENCY 2 5 5 5 10 AERODYNAMIC DIAMETER microns RECOMMENDED SAMPLING PROCEDURES General The Air O Cell CSI sampler is designed to operate at an optimal flow rate of 15 liters per minute The user can employ any sampling pump capable of a minimum flow rate of 15 Ipm It is also capable of operating in any vertical or horizontal orienta tion or in restricted access spaces smaller than 2 inches in diameter As a result the Air O Cell CSI is ideally suited for sampling in HVAC ducts plenums wall cavities or other confined spaces 4 Sampling of Ambient Static Environments A rotameter calibrated to a primary standard soap bubble tube meter or a dry bubble meter should be used to calibrate the sampling pump to a flow rate of 15 lpm Some pumps only work with specific calibration devices Please reference the owner s manual for your pump to verify if a
11. ure 2 ILLUSTRATION OF Air O Cell CSI COUNTING METHOD microscopic slide Air 0 Cell CSI slide analysis starts at 1st traverse completes and moves to 2nd traverse sample particulate Figure 2 The calculation of particle concentration per cubic meter of air can be performed by using the following equations First determine the actual air volume collected in cubic meters m3 by following the calculation given in Equation 1 EQUATION 1 Air volume m Sampling rate liters per minute 1000 x Number of minutes Second determine the length of sample trace counted based on the microscope field of view and number of fields of view counted Accurately calibrate and mea sure the diameter of the microscope field of view using a stage micrometer slide Remember each microscope is different and each different combination of ocular and objective lens must be calibrated separately Stated lens magnifications are rarely precise The microscopist should then record the number of complete tra verses examined across the width of the deposition trace and use the formula given in Equation 2 to calculate the actual length of the deposition trace examined EQUATION 2 Trace Length Counted mm Microscope field diameter mm x number of traverses EQUATION 3 Cts m3 Trace length 14 5mm 1 of particle counts Total length of trace counted Air Volume m From Equation 2 From E
12. wed by a final rinse of deionized or distilled water 2 Remove excess water droplets with a light spray of canned air or dusting spray 3 Placetheslideonawarmingplateatapproximately 125 F 150 Fforapproximately30 minutestodryandcurethesample TransfertheslidetoanSEMspecimenmountand affix with carbon conductive paint silver paint or conductive carbon tabs 4 Apply a bead of conductive carbon or silver paint from the bottom of the specimen mount to at least 2 edges and top surfaces of the CSI cover slip This procedure is required to minimize charging in the sputter coater and electron microscope 10 5 Sputter coat using a gold target and argon as the carrier gas The following coating parameters are recommended e Working distance greater than 5 cm No more than 30mA of current Minimum vacuum pressure of 0 08 torr Coat the slide in 3 increments of 15 seconds for a total of 45 seconds to reduce heating of the sample Coating in steps will minimize heating of the sample and CSI adhesive SEM Analysis Accelerating Voltage Analyze the sample at an SEM accelerating voltage of 15 20kv Note The lower accelerating voltage provides better image and X ray resolution of carbon and light element particles found in IAQ samples It will also minimize sample charging and minimize cracking of the CSI collection media All bioaerosol samplers are not created equal and will not provide the same results All Zefon products provide you
13. with assurance of validated industry proven performance and the highest quality product Ordering Information Field Equipment Product Number Description CSIO10 Air O Cell CSI 10 box AOCIW10 Inner Wall Adapter 10 box AOCCAL In Line Calibration Adapter Zefon INTERNATIONAL Sampling Equipment Specialists a 5350 SW Ist Lane Ocala FL 34474 www zefon com Phone 800 282 0073 352 854 8080 Fax 352 854 7480 0 Sampling Equipment Specialists pes as 5350 SW Ist Lane Ocala FL 34474 www zefon com Phone 800 282 0073 352 854 8080 Fax Fax 352 854 7480 Copyright 2006 Zefon International Inc LAO3037 Rev 1
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