Proceedings of the International Cyanide Detection Testing Workshop

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For the detection of cyanide from biological matrices, no specifi c derivatization is necessary as HCN is volatile. Therefore, the most common pre-analysis step in GC analysis of cyanide is sampling of cyanide from the sample head space. Either equilibrium or dynamic headspace methods can be used to prepare a sample for GC analysis (63, 66, 70, 79, 81, 94, 124, 141, 143, 149, 152, 158). Another pre-analysis step for cyanide analysis is cryogenic oven trapping, which has been used to trap liberated HCN into headspace with high resolution and sensitivity (86, 147). Because thiocyanate and ATCA are nonvolatile, they require chemical modifi cation (normally derivatization) to allow analysis by GC. Chemical modifi cation is also necessary for analysis of cyanide by ECD (because of its poor response) or for simultaneous analysis of cyanide and thiocyanate. Therefore, a number of pretreatment steps have been developed to facilitate the analysis of cyanide, thiocyanate, and ATCA by GC. In GC analysis, the NPD permits the sensitive and specifi c detection of nitrogencontaining compounds, and has been used for the detection of cyanide and thiocyanate in plasma, urine and saliva (79, 83, 145, 146, 150). However, this detector may be unstable at times, and is less sensitive than some other types of GC detectors. This has led to the creation of analytical methods that take advantage of more stable and sensitive detectors such as the ECD and MS. When using ECD detectors in GC analysis of HCN, derivatization is required before analysis. Derivatization of cyanide has been performed by alkylation of cyanide (83) or the conversion of HCN into cyanogen chloride by choramine-T oxidation (Figure 2) (70, 151, 156). Kage and coworkers (83) used GC-ECD to simultaneously analyze cyanide and thiocyanate using an extractive alkylation technique. 82 One of the most sensitive methods for analysis of cyanide, thiocyanate, and ATCA is GC-MS (83, 94). With MS detection, stable isotope standards (e.g. 13 CN for 12 CN) can be used to correct for matrix effects common to cyanide and cyanide metabolites. This can eliminate the need for standard addition techniques and matrix matching. Dumas et al. (94) used stable isotope standards with GC-MS and head space analysis to analyze cyanide concentrations. Kage and co-workers also used GC-MS to analyze both cyanide and thiocyanate simultaneously (83). ATCA has also been analyzed by GC-MS. Logue et al. (45, 157) analyzed ATCA in plasma and urine using GC-MS by fi rst converting the non-volatile metabolite into a volatile form using trimethylsilyl-trifl uoroacetamide. Cyanide-protein adducts have not been analyzed by GC-MS. Suggested procedures for delayed analysis of biological samples For cyanide analysis, a sample should be collected quickly after exposure and cyanide analysis should be performed as soon as possible because of the rapid detoxifi cation of cyanide from blood samples (discussed above). However, if analysis of cyanide cannot be performed quickly and storage of biological samples is necessary, the following should be considered: 1) Volatility and nucleophilicity of cyanide. As described above, HCN is volatile and cyanide ion is nucleophilic. Tightly sealed vials, low temperatures, high pH, and the addition of preserving agents are common procedures that have been used to prevent evaporative loss of cyanide. Storing samples at low temperatures is extremely important to reduce evaporative loss, and slow biochemical reactions. However, there
are many discrepancies in the literature when evaluating the stability of cyanide in biological fl uids under various conditions (43, 87, 131, 172, 179). Generally, nucleophilic losses are reduced by adding sequestering agents (e.g., hydroxocobalamin) or chemicals that produce sequestering agents (e.g. sodium nitrite to produce methemoglobin) (87, 123, 193). One method found to improve cyanide stability is the addition of silver ions to biological samples (87). 2) Cyanide concentration varies in biological components. Cyanide in blood primarily resides in erythrocytes (red blood cells) (64, 82, 87, 174, 194) by binding to methemoglobin, forming cyanomethemoglobin. Cyanide may also be present in plasma, especially if cyanide concentrations exceed erythrocyte concentrations (82, 87). To ensure accurate cyanide concentrations when analyzing blood, collection containers that contain anticoagulants (e.g., heparin) should be used to prevent clotting. Analysis of cyanide from tissues requires knowledge of the behavior of cyanide in specifi c organs since the enzyme that catalyzes conversion of cyanide to thiocyanate has highly variable concentrations depending on the organ. Therefore, in specifi c organs, there will be little to no cyanide because of extremely fast metabolism to thiocyanate. 3) Potential for cyanide formation during storage. Artifactual formation of cyanide may also occur in biological samples depending on storage conditions (77, 172-174). It has been suggested that oxyhemoglobin (175), thiocyanate oxidase (173, 174), and white blood cells (77) may oxidize thiocyanate to cyanide and these reactions are dependent 83 on the temperature and pH of the sample. Microorganisms may also be responsible for cyanide production and low temperature storage will help to eliminate their growth (173). These considerations are common to all the analytical methods for analysis of cyanide from biological samples and certainly contribute to discrepancies in similar studies in the literature. For post-mortem analysis of cyanide, production and transformation of cyanide must be considered when interpreting results along with other considerations discussed above (74, 195-198). Some of the same issues must also be considered for thiocyanate, as a number of problems with storage of samples to be analyzed for thiocyanate have been found (56). This may be due to interconversion of thiocyanate and cyanide over time and the removal and production of thiocyanate by biological processes other than cyanide detoxifi cation (24, 58). It has been suggested that ATCA is not involved in other biological processes and it has been found to be stable during storage (18, 45, 47, 48, 59). While ATCA may not have the storage issues of cyanide and thiocyanate, there is little information on its toxicokinetics, which currently limits its use as a biomarker for cyanide exposure. Also, cyanide-protein adducts have recently been discovered, and therefore little information about the toxicokinetics and stability of these adducts is known. Conclusions The analytical determination of cyanide and its metabolites is not an easy task due to chemical properties, biological activities, and limited research. Numerous methods have been developed and each has its own advantages and disadvantages. However, they
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Proceedings of the International Cy
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Proceedings of the Cyanide Detectio
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ACKNOWLEDGEMENTS The Proceedings of
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PREFACE The International Cyanide D
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EXECUTIVE SUMMARY The International
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ATCA) in homogenized fi sh tissue m
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Validation of the ISE method applie
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Importing countries should also req
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INTRODUCTION Cyanide fi shing is a
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through the implementation of a net
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Working Group 2 The Export Working
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o o o o Can the U.S. require verifi
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Polymeric membrane based ion select
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Goal 2: Provide recommendations on
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hands-on training that develops a d
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Goal 3: Identify research needs to
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Working Group 1 Participants Bob KO
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estimated at roughly 3 to 5 days. H
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Goal 2 : Identify steps, agreements
Page 41 and 42: 3) certifi cate, but tests positive
Page 43 and 44: Report from Working Group 3 The Par
Page 45 and 46: No. of Shipments 6,000 5,000 4,000
Page 47 and 48: Goal 3: Provide a recommendation wi
Page 49: Working Group 3 Participants Eric P
Page 53 and 54: Introduction Since the early 1960
Page 55 and 56: ainbow trout exposed to 40 mg SCN -
Page 57 and 58: Blennies, which were net-caught and
Page 59 and 60: electrical potential (similar to an
Page 61 and 62: in the Philippines under contract w
Page 63 and 64: endorsing the IMA’s use of the IS
Page 65 and 66: The intended products from the rese
Page 67 and 68: WPCF 1992, 1998). Both of these stu
Page 69 and 70: ASTM (1997) Standard test methods f
Page 71 and 72: Kuegsen, M., Kloock, J.P., Knobbe,
Page 73 and 74: Philippines. In Proceedings from th
Page 75 and 76: 3) 4) 5) 6) the metabolism of cyani
Page 77 and 78: or new matrices. 5.2.3 Modifi catio
Page 79 and 80: Level Two: The method should be val
Page 81 and 82: of cyanide exposure and to identify
Page 83 and 84: Special considerations for the anal
Page 85 and 86: tissue samples indispensable. Altho
Page 87 and 88: y reduction and subsequent separati
Page 89 and 90: can also be used for analysis of cy
Page 91: thiocyanate in saliva and serum bas
Page 95 and 96: Table 3. Analytical Methods to dete
Page 97 and 98: Poisoning, In Textbook of military
Page 99 and 100: (70) Odoul, M., Fouillet, B., Nouri
Page 101 and 102: V. (1975) Stable reagents for the c
Page 103 and 104: (159) Felscher, D. and Wulfmeyer, M
Page 105 and 106: Purpose of this Document The purpos
Page 107 and 108: day. One cyanide tablet (2 g) is mi
Page 109 and 110: 10-90% following exposure to cyanid
Page 111 and 112: existing cyanide detection methods
Page 113 and 114: - Plasma lactate — elevated plasm
Page 115 and 116: Method Advantages Disadvantages Hig
Page 117 and 118: Paper Method Matrix Detection Limit
Page 119 and 120: Table 4 lists experts identifi ed t
Page 121 and 122: X Jerry Thomas CDC Em Steve Borron
Page 123 and 124: References Barber, C. and Pratt, V.
Page 125 and 126: Rates of Recovery. Environmental Ma
Page 127: COUNTRY REPORTS
Page 130 and 131: The first three of these destructiv
Page 132 and 133: enforcement is minimal. There is an
Page 134 and 135: 1. Management/guidance to the Minis
Page 136 and 137: in Vietnam now and requires more ef
Page 138 and 139: Figure 2: Administrative structure
Page 140 and 141: References Baquero, J. (1999) Marin
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Acronyms • CDT • Cyanide Detect
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Law/Ordinance/Decree /Decision 52/2
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of samples required for analysis. U
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Field test kit. BFAR recognizes the
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Political Will Having planted the s
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gravely by fi shing communities. Th
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ecome the partner and counterpart o
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Ion-Selective Electrodes for Cyanid
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References Alban, J., Manipula, B.E
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levels with mV readings recorded as
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Trends Determined by Cyanide Testin
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Implementing agencies: • Quaranti
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APPENDIX
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1:30 Overview of and Potential Cyan
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Kristine Johnson Director Kingfi sh
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Assessment of U.S. Role in Trade: U
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