A forensic toxicology laboratory is mainly provided with preserved viscera, body fluids and other biological samples for the determination of presence or absence of toxic substances and their metabolites and to evaluate their role as a determinant or contributory factor in the cause and manner of death or suspect case of poisoning. A forensic toxicology laboratory, also plays an integral role in human performance by determining the absence or presence of poisons and chemicals in blood, breath or other appropriate specimens. A hospital medical toxicology laboratory, has to conduct routine biochemical analysis of patients for therapeutic and academic purpose. It has no responsibility to criminal justice process. But a crime laboratory or forensic toxicology laboratory, has responsibility to the prosecution, the victim, the suspect, the society, the police and judiciary.
Human resource constitutes the backbone of any system. The personnels employed should be efficient, competent, and technically sound. The number of staff members will depend on the work load of the laboratory and can be segregated in three different levels – administrative, technical and non-technical.
Director/Chief Scientist/Chief Toxicologist/Chief Chemist
A forensic toxicology laboratory, should be directed by a person who is qualified by a reason of appropriate education (master degree in chemistry/ forensic science/toxicology) and Doctorate in the field of chemistry/ toxicology and experience to assume the required professional, organizational, educational, managerial and administrative responsibilities. The director should have minimum ten years of fulltime laboratory experience in forensic toxicology laboratory. The director should also have a documented training and experience in the forensic application of analytical toxicology (such as court testimony, research, participation in continuing education programs, including knowledge of evidentiary procedures) that apply when toxicological samples are received, stored, processed, analyzed and toxicological data/reports are submitted as a part of legal proceeding.
Responsibilities of Chief Scientist/Chief Toxicologist/Chief Chemist/Director
The responsibilities of Chief Scientist/Chief toxicologist/Chief chemist/Director are:
- Monitor laboratory practices to verify continuing compliance with policies and procedures.
- Evaluate instrument calibration and the maintenance of records.
- Periodically, assess the adequacy of the report and review the activities.
- Maintain training records of laboratory personnel.
- Recommend training to improve the quality of laboratory staff, etc.
A forensic toxicology laboratory should have a series of forensic scientists as scientist grade III, scientist grade II, scientists grade I. The grades of scientists are based on their experience and expertise. Senior scientist should be looked upon as an individual with considerable expertize and may serve as a training coordinator for new analysts. He should be skilled in demonstration of competency and allowed to report and testify to the case-works in the court of law.
A laboratory technician should have a minimum of bachelors degree in Natural Science/Forensic Science/Chemistry with hands on experience in Analytical Chemistry/Toxicology and capable of performing variety of test procedures for drugs, alcohol and other chemicals.
A laboratory assistant should have bachelors degree in Natural science. He should be capable of performing various test procedures and maintaining proper laboratory records.
A laboratory attendant should have an intermediate (10+2), in Science. The responsibility of laboratory attendant is to clean the laboratory equipments and arrange the chemicals and glasswares, etc.
The non-technical staff consists of clerk, librarian, store-keeper, accountant, viscera cutter, peon and sweeper. The number of non-technical staff should be decided as per the requirement.
The forensic toxicology laboratory should be near the mortuary and must have rapid facility for sample transportation. The building should be in area with ample natural light through windows. The laboratory premises should be well- connected by road transport network. It should have sufficient number of vehicles for transportation and travel of laboratory personnel from time to time. The area for the functional purpose in forensic toxicology laboratory, can be divided into various segments.
PHYSICAL FACILITY, AREA AND SPACE REQUIREMENT
Availability of adequate space and area is one of the prime factors, as it provides the foundation for all further planning and development of the laboratory. The space acquired should be sufficient enough to accommodate all the laboratory buildings, including open area for parking, waste disposal or incineration, etc. The laboratory premises should be well connected with road, or with convenient transport network. The area in the main building can be divided into various segments as follows:
Reception and Visitor Room (Size 150 sq ft)
Visitor room should always be outside the second security gate.
Administrative or Office Room (Size According to Requirement)
It is a place required for all official works.
Laboratory Director/Chief Scientist Room (180 sq ft)
Director room should be situated inside the second security gate for the safety purpose.
Scientists Room (450 sq ft, Three Cabins of 15 × 10 sq ft each)
It is the room for the scientists to perform works such as documentation, report writing, etc. The room can be divided into cabins according to the number of scientists.
Library (360 sq ft)
The scientists and trainees regularly require consultation of reference books, journals, and other literatures during routine case-work and for research purpose. To meet the needs, there must be a library in the laboratory premises, with computer facility and internet connection. It should be fully air conditioned with proper lighting.
Conference or Seminar Room (700 sq ft)
There should be a seminar or conference room for seminars, presentations, conferences, meetings, lectures, etc. It should be well-equipped with a computer and a projector.
Stores (1500 sq ft)
Proper storage facility is required for chemicals and reagents. Stores of glassware and stationary items should be moisture-free and rodent-free.
Chemical Store (200 sq ft)
All chemicals which are used for laboratory working should be present in chemical store. The chemical store should consist of racks divided into blocks to store separate chemicals. This room should be air conditioned with proper ventilation.
Store for Sample or Parcel (900 sq ft)
It is a place to store samples. Store for exhibits, should be divided into two portions, one for incoming (450 sq ft) case parcels and the other for outgoing (450 sq ft) case parcels. A cold chamber should be present in sample store. It should be divided into parts to store samples to prevent contamination. An ultraviolet lamp should be present inside the room for sterilization destroy the micro-organisms. The switch of UV lamp should always be outside the door of the store room. The sample store should always be near the isolation and extraction unit.
Glasswares and Other Consumables (200 sq ft)
It is a place for storing glasswares, gowns, aprons, rubber gloves, gumboots, towels, masks and other consumables.
Stationary Store (200 sq ft)
Most frequently required stationary in forensic toxicology laboratory are case files, registers, working sheets, pen and pencils, packing envelopes, boxes, packing cloths, reporting sheets, papers, carbon sheets, marker pens, etc. All stationary articles should be stored in moisture-free room.
Document Record Room (180 sq ft)
It is a room to maintain all records related to laboratory work, example—old case files, training records, etc. Regulation policy statement, (the laboratory should maintain procedures to control, that form the part of regulatory system) control the data related to testing and calibration memoranda, related softwares, etc. The entire document that form the part of management system control in various media, whether hard copy or soft copy. Procedure manuals should be reviewed and approved for the authorized personnel and authorized edition of appropriate document should be available at all locations, as required for effective functioning of laboratory. Specialization calibration charts, case file reporting performa, analysis of records, books, literature, journals, memorandum, operation manuals, laboratory manuals, safety measurements, photographs, visitor records, employee's attendance records, reviews, requests, tenders and contract records, technical records, etc.
Case Opening Room (225 sq ft)
It is necessary to have a separate case opening room for the purpose of opening the case, parcel. It should be adjacent to the parcel store or preferably in between the parcel store and isolation/extraction room. It should have proper ventilation and exhaust fans.
Toxicology Museum (240 sq ft)
It is useful to have a toxicology museum for academic purpose. It should have all the poison samples properly preserved and labelled with brief facts about the poison. It can be obtained from the authorized supplier. List of items to be placed in toxicology museum has been listed in Table 1.1. Pictorial view of the museum is shown in Figure 1.1.
Area of Sample Analysis
Area of sample analysis can be divided into several sections, such as extraction and isolation unit, screening test unit, sophisticated instrumental unit, washing room, etc.
Extraction and Isolation Unit (525 sq ft)
This room is used for extraction and isolation procedure of samples. The extraction and isolation of poison from postmortem samples and other body fluids is a challenging task and the initial step of isolation and purification of compounds is vital for proper analysis and reliable results. The room should have proper ventilation with at least two exhaust fans and fume hood each. The following instruments are essential in this unit:
- Tissue homogenizer
- Steam distillation unit
- Ice bath
- Ice making machine
- Muffle furnace
- Hot plate
- Microwave digester
- Vortex mixer
- Centrifuge machine
- Water bath
- Fume hood
- Washbasin with continuous water supply.
- Room should be non-air conditioned.
- Electronic balance
- Top-loading balance
Screening Test Unit (300 sq ft)
Screening test is required to individualize a specific group of compounds. It can be done by various spot tests, microcrystal test, TLC, etc. The essential requirements for screening tests are listed as follows.
- Standard reference sample
- pH meter
- Vortex mixer
- Gutziet apparatus
- Breath alcohol analyzer
- TLC preparation system
- UV cabinet
- Immuno-assay kits and reagents
- Sink with continuous water supply
- Kits for rapid screening of drugs
- Conductivity meter
- Melting point apparatus
Sophisticated Analytical Instrumental Unit (950 sq ft)
This unit should contain all sophisticated analytical instruments required for qualitative and quantitative estimation of toxic substances in the case samples and research work. The instruments used in forensic toxicology laboratory should be highly sensitive, because the quantity of material involved is extremely small, often in micro and nanogram level. For a sample material to be identified positively, the techniques should be highly specific and rapid. We have listed the instruments, which are required for proper analysis of samples of routine work, research and development activities and, which require separate room for each instrument:
- UV and visible spectroscopy.
- Fourier transform infrared spectroscopy (FTIR). It must be placed in separate cabin, which must be moisture-free and fitted with dehumidifier.
- High performance thin layer chromatography (HPTLC).
- Gas liquid chromatography (GLC).
- Gas chromatography—mass spectroscopy (GC-MS).
- Liquid chromatography—mass spectroscopy (LC-MS).
- Atomic absorption spectrometry (AAS).
- Inductive coupled plasma (ICP).
Besides above, some other instruments are microwave digester, Ion chromatography, Breath analyzer, voltammetric tracemetal analyzer, pressurized solvent extractor, etc.
Instrumental unit should be fully air conditioned and dust free. All the gas cylinders must be placed in separate cabins outside the instrument rooms. Each instrument should be arranged in separate cabin, if possible.
Washing Room (150 sq ft)
There should be a separate room to clean and wash the used laboratory glasswares, etc. The washing room must have continuous source of water supply, geyser and oven. It should have sufficient space in order to have separate area for chromic acid washing and normal washing. It should have proper ventilation with exhaust fan.
Laboratory work means long hours of standing and walking. It is desirable to have a resilient floor. This reduces breakage. However, the floor should be of a material which is acid, alkali, and salt resistant and can be easily cleaned and disinfected. In washing and sterilizing rooms, moisture resistant floors are preferable.
The walls of the laboratory should be of the permanent, durable construction, but the partitions should be temporary, so that they can be taken out or replaced easily if need arises or activities expand. Finish of the walls must be hard, impermeable, chemically resistant and washable. Tiles as wall finish are desirable only in washing and sterilization rooms.
The ceilings should be made-up of materials that are easily washable and disinfected so as to reduce airborne contamination. The height of ceilings should be 2.5–2.8 m, so as to allow for wall mounted racks and other equipment.
Width of the doors should not be less than 1m wide to allow easy access of equipments. All the doors should open towards the corridor.
As far as possible, sitting of laboratory should be such to allow natural light by providing square windows. Windows should be as tall as possible and should be at least 90 cm above the floor, so that benches can be put below them. Illumination of the laboratory needs to be carefully planned. Artificial light may be of fluorescent type. On the working benches, the intensity of light may be 250–500 lux.
Benching should be so designed that work with microscope can be done on benches running at right angle to the windows and walls. The top of the benches used for seating workers should be 80 cm above floor level, and those of where workers stand should be 90 cm.
Basins for washing hands are essential in all laboratories and should have elbow type taps. Waste pipes should be acid resistant. It is advisable to use PVC piping between sink outlet and connection to the main drainage. Hot water connections are required only at the basins for washing hands and at wash-up sinks. Filtered soft water supply for biochemical investigations is a pre-requisite. Sinks may be of porcelain.
Refrigeration is to be provided in the laboratory. A minimum of two 165 litre capacity is necessary. Refrigeration for storing standards and samples with −40°C must be available.
Intercom facilities should be provided within the laboratory sections and outside stations. Moreover, a dedicated telephone line is required for information of the callers.
A mechanical ventilator system is required in the laboratory areas. In the laboratory where fumes are expected, 10–15 air changes per hour are recommended. In other areas, 4–6 air changes are sufficient.
A system that does not recirculate air is recommended, as laboratory procedures may involve working with an infectious agent.
Due consideration should be given to muffling of the sound produced by running of the equipments. Noise level in the laboratory should not exceed 40–50 dB.
The coloring of the laboratory areas should preferably be lily white or apple, so as to give adequate light as laboratories involve direct observation of many procedures involved.
Fire Protection, Detection and Fighting System
As laboratories are very vulnerable to fire hazards, fire fighting system should be installed in all the laboratory areas.
- Fire hydrants and fire extinguishers should be provided.
- Fire exit routes to be clearly identified and earmarked with red paint and well-illuminated.
Besides normal supply, separate reserve emergency overhead tank should be provided for toxicology laboratory services. Filtered soft water supply for biochemical investigations is a prerequisite for accurate estimations.
Besides providing continuous electricity supply, provision of emergency light and stand by generators for laboratory is to be insured for its smooth functioning.
The glassware requirement in forensic toxicology laboratory varies widely. A wide range of glasswares are required in a forensic toxicology laboratory. These have to be purchased according to the requirement. Only those glasswares that are of certain significance related to analytical procedure are listed in Table 1.2 and shown in Figure 1.2.
Chemicals are required to perform extraction and isolation of poisons, spot tests, solvent systems and chromogenic reagents. Particular attention should be given for insuring a reliable supply of such chemicals. Availability of consumables for chromatographic and other techniques must be guaranteed if equipment is to be used to full advantage. List of minimum required chemicals are given in Table 1.3 and shown in Figure 1.3.
Large number of plastic ware are also required for toxicology lab. It has to be purchased according to the demands. List of minimum required plastic ware are given in Table 1.4 and shown in Figure 1.4.
Equipment and Machinery
We need sophisticated analytical instruments, which are sensitive and reliable for the analysis of poisons in the biological samples. The equipment and machinery can be further divided into two categories, i.e. major equipment and minor equipment.
For quantitative analysis and trace analysis, we need sophisticated analytical instruments such as GLC, AAS, ICP, HPLC, etc. Complete list of major equipment is given in Table 1.5 and shown in Figures 1.5A to N.
Figs 1.5A to H: Major equipment used in laboratory. (A) Gas liquid chromatography (Nucon); (B) High performance liquid chromatography (Dionex Ultimate 3000); (C) UV visible spectrometer (ECIL); (D) Gas chromatography with head space (Perkin Elmer); (E) Atomic absorption spectrophotometer (Analytical Jena); (F) Gas chromatography-mass spectrometer (Perkin Elmer); (G) High performance thin layer chromatography (Desaga); (H) Accelerated solvent extractor (Dionex)
Figs 1.5I to N: Major equipment used in laboratory. (I) Inductive coupled plasma-spectrometry; (J) Fourier–transform infrared spectrometry (varian); (K) Voltammetric trace metal analyzer (Metrohm); (L) Breath analyzer (Uniphos); (M) Ion chromatography (Metrohm); (N) Microwave digester (Aurora)
For qualitative test, color/spot test is done by using some minor equipment. Complete list of minor equipments are given in Table 1.6 and shown in Figures 1.6A to J.
Standards for chemicals, poisons, etc. are essential for standardization and calibration of instruments. A certified reference material (CRM), suitable for the preparation of a standard, to which calibration materials can be compared, must be certified by a method generally recognized by scientific community as one that validates the CRM for this purpose.
Figs 1.6A to H: Minor equipment used in laboratory. (A) pH meter; (B) Ultrasonic bath; (C) Double distillation unit; (D) Muffle furnace; (E) Mini centrifuge; (F) Vortex mixer; (G) Electronic weighing balance; (H) Water bath
Figs 1.6I and J: Minor equipment used in laboratory. (I) Heating mantle; (J) Micropipette controller (Bio Gene)
Reference materials (RMs) should be stored at low temperature or protected from light and moisture. List of Drugs standard, Pesticides standard, Metallic standard, AAS standard, UV-visible spectrophotometer standard are given in Tables 1.7 to 1.11, respectively.
HPLC instruments require special type of solvents called HPLC solvent. List of few HPLC solvents are given in Table 1.12 and shown in Figure 1.7.
Several miscellaneous items are also required in the laboratory for different purposes, which are listed below in Table 1.13 and shown in Figure 1.8.
Waste Disposal Procedures for Biological Material
The laboratory should have documented waste management policy. There must be a clear policy in place for the disposal of materials on completion of examination.
The entire laboratory should be secure and the document and exhibit store area should be strictly prohibited to unauthorized person. The area should be locked by biometric lock. The physical layout of the laboratory must be such that unauthorized person cannot enter without direction and unauthorized person should be escorted and may be required to sign a log book upon entry and exit from the laboratory, recording the full name and address, name of the person to whom the visitor will meet, time, date and purpose of the visit.
In the field of crime investigation, forensic toxicology has a significant role. The deaths due to poisoning are on increase every year with economic advancement and development in science and technology. The poisoning deaths may be due to acute or chronic poisoning. It involves wide range of poisons like agricultural poisons, pharmaceutical drugs, drugs of abuse, household poisons, food poisons, mass disaster due to leakage of chemicals and gases from industries, occupational and environmental hazards, etc.
In India, there are about 35 forensic science laboratories in various states. These laboratories are overburdened with analytical samples due to increasing crimes related to poisoning. And the court of law expects authentic scientific reports as evidence. The government needs to set-up well-planned and equipped forensic toxicology laboratory to deal with poisoning cases.
Layout of forensic toxicology laboratory is given in Figure 1.9. We have tried to describe in detail the manpower requirement, area requirement, equipment, glassware and chemical requirements, along with a clear layout diagram of the laboratory. This chapter provides a detailed guideline for setting up a well-planned modern forensic toxicology laboratory.
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