While the effect of HCl on bone collagen extraction and IRMS measurements have been addressed previously, the effects of the variation of HCl concentration on the measurement of δ¹⁵N analysis have never been reported. To this effect, “chunks” of four right rib shafts from one individual of the skeletal collection of Sainte-Marie-de-Beauce Cemetery (Canada, 1748–1878) were separated in 15 subsamples: three unacidified aliquots of different grain sizes (0–0.125 mm, 0.125 to 1 mm and >1 mm) and four aliquots that underwent three different HCl treatments (1%, 2% or 5%). Each aliquot was analyzed in duplicate or triplicate for δ¹⁵N depending on material availability. The unacidified samples show the largest δ¹⁵N variation (7.5 to 9.2‰) and the mean δ¹⁵N increase with HCl acid concentration, from 9.0‰ vs. AIR (1%) to 9.4‰ (5%). Also, we observe variations in δ¹⁵N from one analytical sequence to another while controls remain invariant. Therefore, we conclude that powdered samples (0–1 mm grain size) have to be thoroughly washed prior to analysis to remove soil contamination in trabecular bone, and that increases in δ¹⁵N in correlation with HCl concentration is likely the result of protein hydrolysis extent from 2 to 5% HCl solutions. Thus, unacidified >1 mm and samples acidified with 1% HCl provide the most reliable %N, C:N and δ¹⁵N values. The analytical sequences of the same sample producing different δ¹⁵N values, while control standards are invariant, remain unexplained. Replication of this study on cortical bones, while monitoring the impact on amino acids, would help to better understand acid pre-treatment effects on δ¹⁵N analysis for diet reconstruction.

虽然盐酸对骨胶原的提取和IRMS测量的影响已得到解决以前，盐酸浓度对的测量的变化的影响δ ¹⁵从未被报道Ñ分析。为此，将Saint-Marie-de-Beauce公墓（加拿大，1748-1878年）的一个骨骼收藏中的四个右肋骨的“块”分为15个子样本：三个不同酸度大小的未酸化的等分试样（0 –0.125毫米，0.125至1毫米和> 1毫米）和四个等分试样，分别接受了三种不同的HCl处理（1％，2％或5％）。每个等分试样一式两份或一式三份分析δ ¹⁵ Ñ根据材料的可用性。在未酸化样品最大δ ¹⁵ Ñ变化（7.5至9.2‰）和平均δ ¹⁵加N用HCl酸浓度，从9.0‰与AIR（1％）至9.4‰（5％）。此外，我们观察到的变化δ ¹⁵ n的一个分析序列到另一个而控制保持不变。因此，我们的结论是粉末样品（0-1毫米粒径）必须被彻底洗涤分析之前，以除去在骨小梁土壤污染，并且在增加δ ¹⁵ N的用HCl浓度的相关性可能是蛋白水解的结果范围从2％到5％的HCl溶液。因此，未酸化> 1毫米，样品用1％HCl酸化提供最可靠的％N，C：N和δ ¹⁵N个值。产生不同的同一样品的分析序列δ ^15个N个值，而控制标准是不变的，仍无法解释。在骨皮质这项研究的复制，同时监控对氨基酸的影响，将有助于更好地了解酸预处理效果δ ^15个ñ分析饮食重建。