What methods are used to compare ink samples?

What methods are used to compare ink samples?

Such approaches include high- performance liquid chromatography, infrared spectroscopy (IR), capillary electrophoresis, and TLC. Research has shown that TLC is a particularly useful method for analyzing inks.

What are the two methods used by investigators in analyzing ink?

Typically, the nondestructive methods include: (1) a visual and microscopic examination of the writing to assess its color and the type of pen used; (2) infrared reflectance and luminescence examinations to determine whether the inks reflect or absorb infrared light and whether the inks luminesce; and (3) viewing the …

How are inks compared in forensics?

Sometimes, the key to determining authenticity of a document lies in the ink that the writer used. This process enables the examiner to accurately determine whether the colors of the two inks match by comparing their light transmission, absorption, and reflection characteristics. …

What method is used to identify the chemical composition of ink once identified how do investigators compare the ink?

Determining individual dye components ― An examination called liquid chromatography can be conducted to identify the chemical composition of inks on a document. In this technique, a small cutting from the questioned document is dissolved in a solvent and analyzed.

What are some ways that forensic scientists can analyze ink?

The most common forensic methods for analyzing inks from documents are thin layer chromatography (TLC) and optical examination [4–9].

How can ink analysis be used to help solve a case?

Forensic scientists are able to use ink chromatography to solve crimes by matching documents or stains found at a crime scene to the marker or pen that belongs to a suspect. Forensic scientists analyze the unknown ink and compare it to writing utensils collected from possible suspects.

What are the different properties of ink?

INK PROPERTIES. There are three basic groups of ink properties: optical properties, structural properties, and drying characteristics. An ink’s color is a function of the pigment used, and an ink’s other optical properties are primarily determined by the pigment characteristics.

Is ink analysis accurate?

This technique managed to spot the age of the ink on documents written up to five years previously and with an approximation margin of about 20%. In these cases, significant dating errors occur because the type of paper used and the mass/quantity of the ink deposited influence the analysis.

How do investigators determine the make and model of a typewriter used to write a ransom note?

Identifying the make and model means that the examiner must have access to a database of typefaces used in various typewriter models, new and old. Most manufacturers use either pica or elite typefaces, but the size, shape, and style of the letters vary, making identification of the manufacturer and model possible.

What are the techniques that can be used in examining questioned papers?

Instruments used in the questioned document section include: Video Spectral Comparator (VSC), Electrostatic Detection Apparatus (ESDA), Stereo-Microscope, Spectrophotometer, and Fingerprint Live Scanner etc.

How do crime scene investigators use ink samples?

How do you analyze ink?

The main method of non-destructive ink analysis is micro-spectrophotometry . This involves scanning the ink with ultraviolet or infrared light to record its spectrum, that is, the wavelengths of light it absorbs. Some inks fluoresce, or emit light, on exposure to ultraviolet, while others disappear.