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Table 1 Chemographic method for GSR analysis

From: Spectroscopic (analytical) approach to gunshot residue analysis for shooting distance estimation: a systematic review

Reference

Test type

Compound detected

Reagent used

Description/color reaction

Ananth, Kalthom, and Me (Ananth et al. 2014)

Dermal nitrate/paraffin test

Nitrate

Diphenylamine dissolved in strong sulfuric acid

Picked up GSR on paraffin wax + reagent gives a blue color spot indicating the presence of nitrates

Chang, Jayaprakash, and Yew (Chang et al. 2013a, b)

Spot test

Lead (Pb)

Sodium rhodizonate

GSR sample + reagent gives a pink coloration indicating the presence of lead.

Saverio Romolo and Margot (2001)

Walker test/Marshal and Tewari test

Nitrite

2-Naphthylamine sulfanilic acid and citric acid

GSR sample + reagent gives a pink coloration for the presence of nitrite

Ananth et al. (2014)

Modified Griess test

Nitrite

Griess reagenta

GSR sample + reagent gives a rose color for the presence of nitrite

Dalby et al. (2010)

Harrison and Gilroy’s test

Lead (Pb), barium (Ba), and antimony (Sb)

• Triphenyl methylarsonium iodide alcoholic solution

• Sodium rhodizonate

• Dilute hydrochloric acid

GSR sample + triphenyl methylarsonium iodide alcoholic solution gives orange ring color for the presence of Sb. Two drops of sodium rhodizonate are added to the center of the orange ring, color changes to red for Pb or Ba or both. A drop of dilute hydrochloric acid is added to the red spot, color changes to blue for Pb. No color change is indicative of Ba

Ananth et al. (2014)

Lunge testb

Nitrocellulose (NC)

Lunge reagent

GSR sample + reagent gives a red azo color for NC

Niewoehner (2015)

Zincon reagent testc

Zinc (Zn) and titanium (Ti)

Zincon reagent

GSR sample + reagent gives a blue-colored complex for Zn and Ti

  1. aGriess reagent: 3% sulfanilamide N-(1-naphthyl) ethylene diamide dihydrochloride in 5% sulfuric acid
  2. bDetect organic compounds (NC) in GSR
  3. cApplied to Pb-free ammunition, e.g., Sintox ammunition