Saturday, January 16, 2016

Onsite real-time analysis of fumigants via GC-PID/TCD



ANYL 335 
PAPER TITLE: Onsite real-time analysis of fumigants via GC-PID/TCD 

DIVISION: Division of Analytical Chemistry
SESSION: Advances in Analytical Separations
SESSION TIME: 8:00 AM - 11:45 AM

PRESENTATION FORMAT: Oral 
DAY & TIME OF PRESENTATION: 9:20am-9:45am 
AUTHORS (FIRST NAME, LAST NAME): John N. Driscoll2 , Jennifer L. Maclachlan1 INSTITUTIONS (ALL): 1. PID Analyzers, LLC, Centerville, MA, United States. 2. PID Analyzers, LLC, Sandwich, MA, United States. ABSTRACT BODY: Abstract: Although many different chemicals have been used as fumigants for agricultural products and soils, we have focused on some of the more common fumigants that can be detected by gas chromtaography (GC) using a photoionization detector (PID). These include methyl bromide, 1,3 dichloropropene, phosphine and methyl isothiocyanate (MITC). Deaths from fumigants have occurred in ships, grain elevators, soil fumigation, green houses, and even residential sites. A field method for detecting common fumigants is essential since many workers encounter these toxic chemicals, which do not have OSHA field detection methods. CA Deptartment of Pesticide Regulation requires that an area which has been fumigated and aerated must be checked for safe levels of that fumigant before entry into the area. Using a Model 312 portable gas chromatograph (GC), which is battery operated and weighs 26 pounds, it is possible to detect ppb levels of some common fumigants with a photoionization detector (PID). A 30M x 0.32 mm capillary with 5 or 10 micron methyl silicone film is used for separating gases and volatile compounds. For phosphine, a 6’ x 1/8” porous polymer column is used for the chromatography since it is a gas. If a thermal conductivity detector (TCD) is used on the same GC, it can detect all of the common fumigants during the fumigation process since it is a universal detector with a response from 0.1% to 100% levels. All of the compounds above have ionization potentials between 10.1 and 10.5 eV so these compounds be detected at ppb levels by GC-PID. The MITC hydrolyzes to methyl isocyanate (MIC), so this is the active component to be detected. The TCD does respond to all of the fumigants both organic and inorganic. A portable GC-PID with a thick film capillary column or a 6’ porous polymer column can detect methyl bromide, 1,3 dichloropropene, phosphine and methyl isothiocyanate (MITC at levels of 0.1 of the PEL. The portable GC is easily carried to the field and can be operational in about 20-30 minutes. If a GC-TCD is also used, the GC-TCD can monitor any of the fumigants during the process of fumigation.

Analytical method development for toxic compounds with a field portable GC/PID



PAPER ID: 2410818 
PAPER TITLE: Analytical method development for toxic compounds with a field portable GC/PID (final paper number: ANYL 333)

DIVISION: Division of Analytical Chemistry
SESSION: Advances in Analytical Separations
SESSION TIME: 8am-11:45am

PRESENTATION FORMAT: Oral
DAY & TIME OF PRESENTATION: 8:30am-8:55am
ROOM & LOCATION: East Coast - Wyndham San Diego Bayfront


AUTHORS (FIRST NAME, LAST NAME): John N. Driscoll2Jennifer L. Maclachlan1
INSTITUTIONS (ALL): 1. PID Analyzers, LLC, Centerville, MA, United States.
2. PID Analyzers, LLC, Sandwich, MA, United States. 
ABSTRACT BODY: 
Abstract: 
There are many situations today that require rapid identification of air toxics in the field. These include spills, train derailments, significant chemical plant leaks, hazardous waste cleanups and more. The equipment must be light weight, battery operated, rugged, sensitive (ppb) or even sub ppb (with a concentrator), and most of all easy to use by first responders. The photoionization detector (PID) has low ppb sensitivity via direct injection, requires no support gases and can be used with a concentrator to measure ppt levels of toxic compounds. Analytical methods for the measurement and identification of chemical agents, benzene, vinyl chloride, acrolein, hydrazine, and chlorinated hydrocarbons will be described using a battery operated Model GC122 weighing less than six pounds. 

New analytical method for the measurement of sub ppb levels of inorganic arsenic in drinking water and fruit juices by HG/GC/PID




PAPER ID: 2385175 
PAPER TITLE: New analytical method for the measurement of sub ppb levels of inorganic arsenic in drinking water and fruit juices by HG/GC/PID (final paper number: ANYL 87)

DIVISION: Division of Analytical Chemistry
SESSION: Analytical Division Poster Session
SESSION TIME: 7pm-9pm

PRESENTATION FORMAT: Poster
DAY & TIME OF PRESENTATION:
ROOM & LOCATION: Hall D - San Diego Convention Center 


AUTHORS (FIRST NAME, LAST NAME): John N. Driscoll2, Jennifer L. Maclachlan1
Joseph Sabol3 INSTITUTIONS (ALL): 1. PID Analyzers, LLC, Centerville, MA, United States. 
2. PID Analyzers, LLC, Sandwich, MA, 3. Chemical Consultant, Racine, WI United States. 
ABSTRACT BODY: 
Abstract: 
Cutter and others (1) described Hydride Generation (HG) with Gas Chromatography (GC)/Photoionization Detector (PID) with a liquid nitrogen concentrator more than twenty-five years ago for part per billion (ppb) detection of metalloids such as As, Sb and Se, in natural waters. These early papers on HG/GC/PID (1 ) used a liquid nitrogen trap to collect the AsH3 from the hydride generator. The trap was heated to drive off the concentrated AsHsample into the GC. Cutter (2) has continued his work on the analysis of As in natural waters with GC/PID and is able to detect 0.75 parts per trillion (ppt) of As. An additional advantage of this PID method is that it could also be used to detect organoarsenic compounds.
Driscoll and Maclachlan described a modified HG/GC/PID method for the analysis of ppb levels of arsenic in drinking water and apple juice at the American Chemical Society meeting in New Orleans in 2013 (3). We have used that method and developed modifications and significant improvements including the elimination of the liquid nitrogen concentrator and detection of sub ppb levels of As.
The advantages of the new HG/GC/PID analytical method are that it does not use liquid nitrogen, is easy to use, can determine inorganic arsenic (As+3 & As+5), does not require a high level of operator training and the capital cost is a fraction of Graphite Furnace Atomic Adsorption (GFAAS), or LC/ICP/MS system. This HG/GC/PID method will be described in detail in this paper.
References:
1 Cutter LS, GA Cutter, San Diego McGlone, Anal Chem 63,1138 (1991)
2 Cutter, G. A., and Cutter, L. S. (2006). Biogeochemistry of arsenic and antimony in the North Pacific Ocean.Geochemistry, Geophysics, Geosystems, 7 (5),
3 Driscoll, JN and Jennifer MacLachlan, ACS National Meeting NOLA (2013), Division of Agriculture and Food Chemistry,Comparison of sensitive methods for the measurement of inorganic arsenic in apple juice: Photoionization (PID)and ICP-MS